diff --git a/internal/pkg/core/openolt_flowmgr.go b/internal/pkg/core/openolt_flowmgr.go
new file mode 100644
index 0000000..449afe8
--- /dev/null
+++ b/internal/pkg/core/openolt_flowmgr.go
@@ -0,0 +1,4119 @@
+/*
+ * Copyright 2020-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//Package core provides the utility for olt devices, flows and statistics
+package core
+
+import (
+	"context"
+	"crypto/md5"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"math/big"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/opencord/voltha-lib-go/v3/pkg/flows"
+	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	tp "github.com/opencord/voltha-lib-go/v3/pkg/techprofile"
+	rsrcMgr "github.com/opencord/voltha-openolt-adapter/internal/pkg/resourcemanager"
+	"github.com/opencord/voltha-protos/v3/go/common"
+	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
+	ofp "github.com/opencord/voltha-protos/v3/go/openflow_13"
+	openoltpb2 "github.com/opencord/voltha-protos/v3/go/openolt"
+	tp_pb "github.com/opencord/voltha-protos/v3/go/tech_profile"
+	"github.com/opencord/voltha-protos/v3/go/voltha"
+
+	"github.com/EagleChen/mapmutex"
+	"github.com/opencord/voltha-openolt-adapter/internal/pkg/olterrors"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+const (
+
+	HsiaFlow = "HSIA_FLOW"
+
+	EapolFlow = "EAPOL_FLOW"
+
+	DhcpFlow = "DHCP_FLOW"
+
+	MulticastFlow = "MULTICAST_FLOW"
+
+	IgmpFlow = "IGMP_FLOW"
+
+	IPProtoDhcp = 17
+
+	IPProtoIgmp = 2
+
+	EapEthType = 0x888e
+	LldpEthType = 0x88cc
+	IPv4EthType = 0x800
+
+	IgmpProto = 2
+
+	ReservedVlan = 4096
+
+	DefaultMgmtVlan = 4091
+
+
+	Upstream = "upstream"
+	Downstream = "downstream"
+	Multicast = "multicast"
+	PacketTagType = "pkt_tag_type"
+	Untagged = "untagged"
+	SingleTag = "single_tag"
+	DoubleTag = "double_tag"
+
+
+	EthType = "eth_type"
+	EthDst = "eth_dst"
+	TPID = "tpid"
+	IPProto = "ip_proto"
+	InPort = "in_port"
+	VlanVid = "vlan_vid"
+	VlanPcp = "vlan_pcp"
+
+	UDPDst = "udp_dst"
+	UDPSrc = "udp_src"
+	Ipv4Dst = "ipv4_dst"
+	Ipv4Src = "ipv4_src"
+	Metadata = "metadata"
+	TunnelID = "tunnel_id"
+	Output = "output"
+	GroupID = "group_id"
+
+	PopVlan = "pop_vlan"
+	PushVlan = "push_vlan"
+	TrapToHost = "trap_to_host"
+	MaxMeterBand = 2
+	VlanPCPMask = 0xFF
+	VlanvIDMask = 0xFFF
+	IntfID = "intfId"
+	OnuID = "onuId"
+	UniID = "uniId"
+	PortNo = "portNo"
+	AllocID = "allocId"
+
+	NoneOnuID = -1
+	NoneUniID = -1
+	NoneGemPortID = -1
+
+	BinaryStringPrefix = "0b"
+	BinaryBit1 = '1'
+
+	maxRetry  = 300
+	maxDelay  = 100000000
+	baseDelay = 10000000
+	factor    = 1.1
+	jitter    = 0.2
+)
+
+type gemPortKey struct {
+	intfID  uint32
+	gemPort uint32
+}
+
+type pendingFlowDeleteKey struct {
+	intfID uint32
+	onuID  uint32
+	uniID  uint32
+}
+
+type tpLockKey struct {
+	intfID uint32
+	onuID  uint32
+	uniID  uint32
+}
+
+type schedQueue struct {
+	direction    tp_pb.Direction
+	intfID       uint32
+	onuID        uint32
+	uniID        uint32
+	tpID         uint32
+	uniPort      uint32
+	tpInst       interface{}
+	meterID      uint32
+	flowMetadata *voltha.FlowMetadata
+}
+
+type queueInfoBrief struct {
+	gemPortID       uint32
+	servicePriority uint32
+}
+
+//OpenOltFlowMgr creates the Structure of OpenOltFlowMgr obj
+type OpenOltFlowMgr struct {
+	techprofile        map[uint32]tp.TechProfileIf
+	deviceHandler      *DeviceHandler
+	resourceMgr        *rsrcMgr.OpenOltResourceMgr
+	onuIdsLock         sync.RWMutex
+	perGemPortLock     *mapmutex.Mutex                    // lock to be used to access the flowsUsedByGemPort map
+	flowsUsedByGemPort map[gemPortKey][]uint32            //gem port id to flow ids
+	packetInGemPort    map[rsrcMgr.PacketInInfoKey]uint32 //packet in gem port local cache
+	onuGemInfo map[uint32][]rsrcMgr.OnuGemInfo //onu, gem and uni info local cache, indexed by IntfId
+	onuGemInfoLock    sync.RWMutex
+	pendingFlowDelete sync.Map
+	perUserFlowHandleLock    *mapmutex.Mutex
+	interfaceToMcastQueueMap map[uint32]*queueInfoBrief /*pon interface -> multicast queue map. Required to assign GEM to a bucket during group population*/
+}
+
+var autoAddFlow bool = true
+var noticeDownloadRequest bool = false
+var mapCreateScheduler map[string]bool = map[string]bool{}
+var mapAddFlow map[string]bool = map[string]bool{}
+
+func resetFlowMap() {
+	mapCreateScheduler = map[string]bool{}
+	mapAddFlow = map[string]bool{}
+}
+
+//NewFlowManager creates OpenOltFlowMgr object and initializes the parameters
+func NewFlowManager(ctx context.Context, dh *DeviceHandler, rMgr *rsrcMgr.OpenOltResourceMgr) *OpenOltFlowMgr {
+	logger.Infow(ctx, "initializing-flow-manager", log.Fields{"device-id": dh.device.Id})
+	var flowMgr OpenOltFlowMgr
+	var err error
+	var idx uint32
+
+	flowMgr.deviceHandler = dh
+	flowMgr.resourceMgr = rMgr
+	flowMgr.techprofile = make(map[uint32]tp.TechProfileIf)
+	if err = flowMgr.populateTechProfilePerPonPort(ctx); err != nil {
+		logger.Errorw(ctx, "error-while-populating-tech-profile-mgr", log.Fields{"error": err})
+		return nil
+	}
+	flowMgr.onuIdsLock = sync.RWMutex{}
+	flowMgr.flowsUsedByGemPort = make(map[gemPortKey][]uint32)
+	flowMgr.packetInGemPort = make(map[rsrcMgr.PacketInInfoKey]uint32)
+	ponPorts := rMgr.DevInfo.GetPonPorts()
+	flowMgr.onuGemInfo = make(map[uint32][]rsrcMgr.OnuGemInfo, ponPorts)
+	for idx = 0; idx < ponPorts; idx++ {
+		if flowMgr.onuGemInfo[idx], err = rMgr.GetOnuGemInfo(ctx, idx); err != nil {
+			logger.Error(ctx, "failed-to-load-onu-gem-info-cache")
+		}
+		//Load flowID list per gem map per interface from the kvstore.
+		flowMgr.loadFlowIDlistForGem(ctx, idx)
+	}
+	flowMgr.onuGemInfoLock = sync.RWMutex{}
+	flowMgr.pendingFlowDelete = sync.Map{}
+	flowMgr.perUserFlowHandleLock = mapmutex.NewCustomizedMapMutex(maxRetry, maxDelay, baseDelay, factor, jitter)
+	flowMgr.perGemPortLock = mapmutex.NewCustomizedMapMutex(maxRetry, maxDelay, baseDelay, factor, jitter)
+	flowMgr.interfaceToMcastQueueMap = make(map[uint32]*queueInfoBrief)
+	flowMgr.loadInterfaceToMulticastQueueMap(ctx)
+	logger.Info(ctx, "initialization-of-flow-manager-success")
+	return &flowMgr
+}
+
+func (f *OpenOltFlowMgr) registerFlow(ctx context.Context, flowFromCore *ofp.OfpFlowStats, deviceFlow *openoltpb2.Flow) error {
+	gemPK := gemPortKey{uint32(deviceFlow.AccessIntfId), uint32(deviceFlow.GemportId)}
+	if f.perGemPortLock.TryLock(gemPK) {
+		logger.Debugw(ctx, "registering-flow-for-device ",
+			log.Fields{
+				"flow":      flowFromCore,
+				"device-id": f.deviceHandler.device.Id})
+		flowIDList, ok := f.flowsUsedByGemPort[gemPK]
+		if !ok {
+			flowIDList = []uint32{deviceFlow.FlowId}
+		}
+		flowIDList = appendUnique(flowIDList, deviceFlow.FlowId)
+		f.flowsUsedByGemPort[gemPK] = flowIDList
+
+		f.perGemPortLock.Unlock(gemPK)
+
+		// update the flowids for a gem to the KVstore
+		return f.resourceMgr.UpdateFlowIDsForGem(ctx, uint32(deviceFlow.AccessIntfId), uint32(deviceFlow.GemportId), flowIDList)
+	}
+	logger.Error(ctx, "failed-to-acquire-per-gem-port-lock",
+		log.Fields{
+			"flow-from-core": flowFromCore,
+			"device-id":      f.deviceHandler.device.Id,
+			"key":            gemPK,
+		})
+	return olterrors.NewErrAdapter("failed-to-acquire-per-gem-port-lock", log.Fields{
+		"flow-from-core": flowFromCore,
+		"device-id":      f.deviceHandler.device.Id,
+		"key":            gemPK,
+	}, nil)
+}
+
+func (f *OpenOltFlowMgr) divideAndAddFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32,
+	classifierInfo map[string]interface{}, actionInfo map[string]interface{}, flow *ofp.OfpFlowStats, TpID uint32,
+	UsMeterID uint32, DsMeterID uint32, flowMetadata *voltha.FlowMetadata) {
+	var allocID uint32
+	var gemPorts []uint32
+	var TpInst interface{}
+
+	logger.Infow(ctx, "dividing-flow", log.Fields{
+		"device-id":  f.deviceHandler.device.Id,
+		"intf-id":    intfID,
+		"onu-id":     onuID,
+		"uni-id":     uniID,
+		"port-no":    portNo,
+		"classifier": classifierInfo,
+		"action":     actionInfo,
+		"usmeter-iD": UsMeterID,
+		"dsmeter-iD": DsMeterID,
+		"tp-id":      TpID})
+	if onuID == 0 {
+		logger.Errorw(ctx, "no-onu-id-for-flow",
+			log.Fields{
+				"port-no":   portNo,
+				"classifer": classifierInfo,
+				"action":    actionInfo,
+				"device-id": f.deviceHandler.device.Id})
+		return
+	}
+
+	uni := getUniPortPath(f.deviceHandler.device.Id, intfID, int32(onuID), int32(uniID))
+	logger.Debugw(ctx, "uni-port-path", log.Fields{
+		"uni":       uni,
+		"device-id": f.deviceHandler.device.Id})
+
+	tpLockMapKey := tpLockKey{intfID, onuID, uniID}
+	if f.perUserFlowHandleLock.TryLock(tpLockMapKey) {
+		logger.Debugw(ctx, "dividing-flow-create-tcont-gem-ports", log.Fields{
+			"device-id":  f.deviceHandler.device.Id,
+			"intf-id":    intfID,
+			"onu-id":     onuID,
+			"uni-id":     uniID,
+			"port-no":    portNo,
+			"classifier": classifierInfo,
+			"action":     actionInfo,
+			"usmeter-id": UsMeterID,
+			"dsmeter-id": DsMeterID,
+			"tp-id":      TpID})
+		allocID, gemPorts, TpInst = f.createTcontGemports(ctx, intfID, onuID, uniID, uni, portNo, TpID, UsMeterID, DsMeterID, flowMetadata)
+		if allocID == 0 || gemPorts == nil || TpInst == nil {
+			logger.Error(ctx, "alloc-id-gem-ports-tp-unavailable")
+			f.perUserFlowHandleLock.Unlock(tpLockMapKey)
+			return
+		}
+		args := make(map[string]uint32)
+		args[IntfID] = intfID
+		args[OnuID] = onuID
+		args[UniID] = uniID
+		args[PortNo] = portNo
+		args[AllocID] = allocID
+
+		/* Flows can be added specific to gemport if p-bits are received.
+		 * If no pbit mentioned then adding flows for all gemports
+		 */
+		f.checkAndAddFlow(ctx, args, classifierInfo, actionInfo, flow, TpInst, gemPorts, TpID, uni)
+		f.perUserFlowHandleLock.Unlock(tpLockMapKey)
+	} else {
+		logger.Errorw(ctx, "failed-to-acquire-per-user-flow-handle-lock",
+			log.Fields{
+				"intf-id":     intfID,
+				"onu-id":      onuID,
+				"uni-id":      uniID,
+				"flow-id":     flow.Id,
+				"flow-cookie": flow.Cookie,
+				"device-id":   f.deviceHandler.device.Id})
+		return
+	}
+}
+
+// CreateSchedulerQueues creates traffic schedulers on the device with the given scheduler configuration and traffic shaping info
+func (f *OpenOltFlowMgr) CreateSchedulerQueues(ctx context.Context, sq schedQueue) error {
+
+	logger.Debugw(ctx, "CreateSchedulerQueues",
+		log.Fields{"dir": sq.direction,
+			"intf-id":      sq.intfID,
+			"onu-id":       sq.onuID,
+			"uni-id":       sq.uniID,
+			"tp-id":        sq.tpID,
+			"meter-id":     sq.meterID,
+			"tp-inst":      sq.tpInst,
+			"flowmetadata": sq.flowMetadata,
+			"device-id":    f.deviceHandler.device.Id})
+
+	Direction, err := verifyMeterIDAndGetDirection(sq.meterID, sq.direction)
+	if err != nil {
+		return err
+	}
+
+	/* Lets make a simple assumption that if the meter-id is present on the KV store,
+	 * then the scheduler and queues configuration is applied on the OLT device
+	 * in the given direction.
+	 */
+
+	var SchedCfg *tp_pb.SchedulerConfig
+	KvStoreMeter, err := f.resourceMgr.GetMeterIDForOnu(ctx, Direction, sq.intfID, sq.onuID, sq.uniID, sq.tpID)
+	if err != nil {
+		return olterrors.NewErrNotFound("meter",
+			log.Fields{"intf-id": sq.intfID,
+				"onu-id":    sq.onuID,
+				"uni-id":    sq.uniID,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	if KvStoreMeter != nil {
+		if KvStoreMeter.MeterId == sq.meterID {
+			logger.Debugw(ctx, "scheduler-already-created-for-upstream", log.Fields{"device-id": f.deviceHandler.device.Id})
+			return nil
+		}
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"unsupported":       "meter-id",
+			"kv-store-meter-id": KvStoreMeter.MeterId,
+			"meter-id-in-flow":  sq.meterID,
+			"device-id":         f.deviceHandler.device.Id}, nil)
+	}
+
+	logger.Debugw(ctx, "meter-does-not-exist-creating-new",
+		log.Fields{
+			"meter-id":  sq.meterID,
+			"direction": Direction,
+			"device-id": f.deviceHandler.device.Id})
+
+	if sq.direction == tp_pb.Direction_UPSTREAM {
+		SchedCfg, err = f.techprofile[sq.intfID].GetUsScheduler(ctx, sq.tpInst.(*tp.TechProfile))
+	} else if sq.direction == tp_pb.Direction_DOWNSTREAM {
+		SchedCfg, err = f.techprofile[sq.intfID].GetDsScheduler(ctx, sq.tpInst.(*tp.TechProfile))
+	}
+
+	if err != nil {
+		return olterrors.NewErrNotFound("scheduler-config",
+			log.Fields{
+				"intf-id":   sq.intfID,
+				"direction": sq.direction,
+				"tp-inst":   sq.tpInst,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	var meterConfig *ofp.OfpMeterConfig
+	if sq.flowMetadata != nil {
+		for _, meter := range sq.flowMetadata.Meters {
+			if sq.meterID == meter.MeterId {
+				meterConfig = meter
+				logger.Debugw(ctx, "found-meter-config-from-flowmetadata",
+					log.Fields{"meterConfig": meterConfig,
+						"device-id": f.deviceHandler.device.Id})
+				break
+			}
+		}
+	} else {
+		logger.Errorw(ctx, "flow-metadata-not-present-in-flow", log.Fields{"device-id": f.deviceHandler.device.Id})
+	}
+	if meterConfig == nil {
+		return olterrors.NewErrNotFound("meterbands", log.Fields{
+			"reason":        "Could-not-get-meterbands-from-flowMetadata",
+			"flow-metadata": sq.flowMetadata,
+			"meter-id":      sq.meterID,
+			"device-id":     f.deviceHandler.device.Id}, nil)
+	} else if len(meterConfig.Bands) < MaxMeterBand {
+		logger.Errorw(ctx, "invalid-number-of-bands-in-meter",
+			log.Fields{"Bands": meterConfig.Bands,
+				"meter-id":  sq.meterID,
+				"device-id": f.deviceHandler.device.Id})
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"reason":          "Invalid-number-of-bands-in-meter",
+			"meterband-count": len(meterConfig.Bands),
+			"metabands":       meterConfig.Bands,
+			"meter-id":        sq.meterID,
+			"device-id":       f.deviceHandler.device.Id}, nil)
+	}
+	cir := meterConfig.Bands[0].Rate
+	cbs := meterConfig.Bands[0].BurstSize
+	eir := meterConfig.Bands[1].Rate
+	ebs := meterConfig.Bands[1].BurstSize
+	pir := cir + eir
+	pbs := cbs + ebs
+	TrafficShaping := &tp_pb.TrafficShapingInfo{Cir: cir, Cbs: cbs, Pir: pir, Pbs: pbs}
+
+	TrafficSched := []*tp_pb.TrafficScheduler{f.techprofile[sq.intfID].GetTrafficScheduler(sq.tpInst.(*tp.TechProfile), SchedCfg, TrafficShaping)}
+	TrafficSched[0].TechProfileId = sq.tpID
+
+	if err := f.pushSchedulerQueuesToDevice(ctx, sq, TrafficShaping, TrafficSched); err != nil {
+		return olterrors.NewErrAdapter("failure-pushing-traffic-scheduler-and-queues-to-device",
+			log.Fields{"intf-id": sq.intfID,
+				"direction": sq.direction,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	/* After we successfully applied the scheduler configuration on the OLT device,
+	 * store the meter id on the KV store, for further reference.
+	 */
+	if err := f.resourceMgr.UpdateMeterIDForOnu(ctx, Direction, sq.intfID, sq.onuID, sq.uniID, sq.tpID, meterConfig); err != nil {
+		return olterrors.NewErrAdapter("failed-updating-meter-id",
+			log.Fields{"onu-id": sq.onuID,
+				"meter-id":  sq.meterID,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	logger.Infow(ctx, "updated-meter-info-into-kv-store-successfully",
+		log.Fields{"direction": Direction,
+			"Meter":     meterConfig,
+			"device-id": f.deviceHandler.device.Id})
+
+	return nil
+}
+
+func (f *OpenOltFlowMgr) pushSchedulerQueuesToDevice(ctx context.Context, sq schedQueue, TrafficShaping *tp_pb.TrafficShapingInfo, TrafficSched []*tp_pb.TrafficScheduler) error {
+	trafficQueues, err := f.techprofile[sq.intfID].GetTrafficQueues(ctx, sq.tpInst.(*tp.TechProfile), sq.direction)
+
+	if err != nil {
+		return olterrors.NewErrAdapter("unable-to-construct-traffic-queue-configuration",
+			log.Fields{"intf-id": sq.intfID,
+				"direction": sq.direction,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	logger.Debugw(ctx, "sending-traffic-scheduler-create-to-device",
+		log.Fields{
+			"direction":     sq.direction,
+			"TrafficScheds": TrafficSched,
+			"device-id":     f.deviceHandler.device.Id})
+	if _, err := f.deviceHandler.Client.CreateTrafficSchedulers(ctx, &tp_pb.TrafficSchedulers{
+		IntfId: sq.intfID, OnuId: sq.onuID,
+		UniId: sq.uniID, PortNo: sq.uniPort,
+		TrafficScheds: TrafficSched}); err != nil {
+		return olterrors.NewErrAdapter("failed-to-create-traffic-schedulers-in-device", log.Fields{"TrafficScheds": TrafficSched}, err)
+	}
+	logger.Infow(ctx, "successfully-created-traffic-schedulers", log.Fields{
+		"direction":      sq.direction,
+		"traffic-queues": trafficQueues,
+		"device-id":      f.deviceHandler.device.Id})
+
+	logger.Debugw(ctx, "sending-traffic-queues-create-to-device",
+		log.Fields{"direction": sq.direction,
+			"traffic-queues": trafficQueues,
+			"device-id":      f.deviceHandler.device.Id})
+	if _, err := f.deviceHandler.Client.CreateTrafficQueues(ctx,
+		&tp_pb.TrafficQueues{IntfId: sq.intfID, OnuId: sq.onuID,
+			UniId: sq.uniID, PortNo: sq.uniPort,
+			TrafficQueues: trafficQueues,
+			TechProfileId: TrafficSched[0].TechProfileId}); err != nil {
+		return olterrors.NewErrAdapter("failed-to-create-traffic-queues-in-device", log.Fields{"traffic-queues": trafficQueues}, err)
+	}
+	logger.Infow(ctx, "successfully-created-traffic-schedulers", log.Fields{
+		"direction":      sq.direction,
+		"traffic-queues": trafficQueues,
+		"device-id":      f.deviceHandler.device.Id})
+
+	if sq.direction == tp_pb.Direction_DOWNSTREAM {
+		multicastTrafficQueues := f.techprofile[sq.intfID].GetMulticastTrafficQueues(ctx, sq.tpInst.(*tp.TechProfile))
+		if len(multicastTrafficQueues) > 0 {
+			if _, present := f.interfaceToMcastQueueMap[sq.intfID]; !present {
+				//assumed that there is only one queue per PON for the multicast service
+				//the default queue with multicastQueuePerPonPort.Priority per a pon interface is used for multicast service
+				//just put it in interfaceToMcastQueueMap to use for building group members
+				logger.Debugw(ctx, "multicast-traffic-queues", log.Fields{"device-id": f.deviceHandler.device.Id})
+				multicastQueuePerPonPort := multicastTrafficQueues[0]
+				f.interfaceToMcastQueueMap[sq.intfID] = &queueInfoBrief{
+					gemPortID:       multicastQueuePerPonPort.GemportId,
+					servicePriority: multicastQueuePerPonPort.Priority,
+				}
+				//also store the queue info in kv store
+				if err := f.resourceMgr.AddMcastQueueForIntf(ctx, sq.intfID, multicastQueuePerPonPort.GemportId, multicastQueuePerPonPort.Priority); err != nil {
+					logger.Errorw(ctx, "failed-to-add-mcast-queue", log.Fields{"error": err})
+					return err
+				}
+
+				logger.Infow(ctx, "multicast-queues-successfully-updated", log.Fields{"device-id": f.deviceHandler.device.Id})
+			}
+		}
+	}
+	return nil
+}
+
+// RemoveSchedulerQueues removes the traffic schedulers from the device based on the given scheduler configuration and traffic shaping info
+func (f *OpenOltFlowMgr) RemoveSchedulerQueues(ctx context.Context, sq schedQueue) error {
+
+	var Direction string
+	var SchedCfg *tp_pb.SchedulerConfig
+	var err error
+	logger.Infow(ctx, "removing-schedulers-and-queues-in-olt",
+		log.Fields{
+			"direction": sq.direction,
+			"intf-id":   sq.intfID,
+			"onu-id":    sq.onuID,
+			"uni-id":    sq.uniID,
+			"uni-port":  sq.uniPort,
+			"device-id": f.deviceHandler.device.Id})
+	if sq.direction == tp_pb.Direction_UPSTREAM {
+		SchedCfg, err = f.techprofile[sq.intfID].GetUsScheduler(ctx, sq.tpInst.(*tp.TechProfile))
+		Direction = "upstream"
+	} else if sq.direction == tp_pb.Direction_DOWNSTREAM {
+		SchedCfg, err = f.techprofile[sq.intfID].GetDsScheduler(ctx, sq.tpInst.(*tp.TechProfile))
+		Direction = "downstream"
+	}
+
+	if err != nil {
+		return olterrors.NewErrNotFound("scheduler-config",
+			log.Fields{
+				"int-id":    sq.intfID,
+				"direction": sq.direction,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	KVStoreMeter, err := f.resourceMgr.GetMeterIDForOnu(ctx, Direction, sq.intfID, sq.onuID, sq.uniID, sq.tpID)
+	if err != nil {
+		return olterrors.NewErrNotFound("meter",
+			log.Fields{
+				"onu-id":    sq.onuID,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	if KVStoreMeter == nil {
+		logger.Warnw(ctx, "no-meter-installed-yet",
+			log.Fields{
+				"direction": Direction,
+				"intf-id":   sq.intfID,
+				"onu-id":    sq.onuID,
+				"uni-id":    sq.uniID,
+				"device-id": f.deviceHandler.device.Id})
+		return nil
+	}
+	cir := KVStoreMeter.Bands[0].Rate
+	cbs := KVStoreMeter.Bands[0].BurstSize
+	eir := KVStoreMeter.Bands[1].Rate
+	ebs := KVStoreMeter.Bands[1].BurstSize
+	pir := cir + eir
+	pbs := cbs + ebs
+
+	TrafficShaping := &tp_pb.TrafficShapingInfo{Cir: cir, Cbs: cbs, Pir: pir, Pbs: pbs}
+
+	TrafficSched := []*tp_pb.TrafficScheduler{f.techprofile[sq.intfID].GetTrafficScheduler(sq.tpInst.(*tp.TechProfile), SchedCfg, TrafficShaping)}
+	TrafficSched[0].TechProfileId = sq.tpID
+
+	TrafficQueues, err := f.techprofile[sq.intfID].GetTrafficQueues(ctx, sq.tpInst.(*tp.TechProfile), sq.direction)
+	if err != nil {
+		return olterrors.NewErrAdapter("unable-to-construct-traffic-queue-configuration",
+			log.Fields{
+				"intf-id":   sq.intfID,
+				"direction": sq.direction,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	if _, err = f.deviceHandler.Client.RemoveTrafficQueues(ctx,
+		&tp_pb.TrafficQueues{IntfId: sq.intfID, OnuId: sq.onuID,
+			UniId: sq.uniID, PortNo: sq.uniPort,
+			TrafficQueues: TrafficQueues,
+			TechProfileId: TrafficSched[0].TechProfileId}); err != nil {
+		return olterrors.NewErrAdapter("unable-to-remove-traffic-queues-from-device",
+			log.Fields{
+				"intf-id":        sq.intfID,
+				"traffic-queues": TrafficQueues,
+				"device-id":      f.deviceHandler.device.Id}, err)
+	}
+	logger.Infow(ctx, "removed-traffic-queues-successfully", log.Fields{"device-id": f.deviceHandler.device.Id})
+	if _, err = f.deviceHandler.Client.RemoveTrafficSchedulers(ctx, &tp_pb.TrafficSchedulers{
+		IntfId: sq.intfID, OnuId: sq.onuID,
+		UniId: sq.uniID, PortNo: sq.uniPort,
+		TrafficScheds: TrafficSched}); err != nil {
+		return olterrors.NewErrAdapter("unable-to-remove-traffic-schedulers-from-device",
+			log.Fields{
+				"intf-id":            sq.intfID,
+				"traffic-schedulers": TrafficSched}, err)
+	}
+
+	logger.Infow(ctx, "removed-traffic-schedulers-successfully", log.Fields{"device-id": f.deviceHandler.device.Id})
+
+	/* After we successfully remove the scheduler configuration on the OLT device,
+	 * delete the meter id on the KV store.
+	 */
+	err = f.resourceMgr.RemoveMeterIDForOnu(ctx, Direction, sq.intfID, sq.onuID, sq.uniID, sq.tpID)
+	if err != nil {
+		return olterrors.NewErrAdapter("unable-to-remove-meter",
+			log.Fields{
+				"onu":       sq.onuID,
+				"meter":     KVStoreMeter.MeterId,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	logger.Infow(ctx, "removed-meter-from-KV-store-successfully",
+		log.Fields{
+			"meter-id":  KVStoreMeter.MeterId,
+			"dir":       Direction,
+			"device-id": f.deviceHandler.device.Id})
+	return err
+}
+
+// This function allocates tconts and GEM ports for an ONU
+func (f *OpenOltFlowMgr) createTcontGemports(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, uni string, uniPort uint32, TpID uint32, UsMeterID uint32, DsMeterID uint32, flowMetadata *voltha.FlowMetadata) (uint32, []uint32, interface{}) {
+	var allocIDs []uint32
+	var allgemPortIDs []uint32
+	var gemPortIDs []uint32
+	tpInstanceExists := false
+	var err error
+
+	allocIDs = f.resourceMgr.GetCurrentAllocIDsForOnu(ctx, intfID, onuID, uniID)
+	allgemPortIDs = f.resourceMgr.GetCurrentGEMPortIDsForOnu(ctx, intfID, onuID, uniID)
+
+	tpPath := f.getTPpath(ctx, intfID, uni, TpID)
+
+	logger.Debugw(ctx, "creating-new-tcont-and-gem", log.Fields{
+		"intf-id":   intfID,
+		"onu-id":    onuID,
+		"uni-id":    uniID,
+		"device-id": f.deviceHandler.device.Id,
+		"tp-id":     TpID})
+
+	techProfileInstance, _ := f.techprofile[intfID].GetTPInstanceFromKVStore(ctx, TpID, tpPath)
+	if techProfileInstance == nil {
+		logger.Infow(ctx, "tp-instance-not-found--creating-new",
+			log.Fields{
+				"path":      tpPath,
+				"device-id": f.deviceHandler.device.Id})
+		techProfileInstance, err = f.techprofile[intfID].CreateTechProfInstance(ctx, TpID, uni, intfID)
+		if err != nil {
+			// This should not happen, something wrong in KV backend transaction
+			logger.Errorw(ctx, "tp-instance-create-failed",
+				log.Fields{
+					"error":     err,
+					"tp-id":     TpID,
+					"device-id": f.deviceHandler.device.Id})
+			return 0, nil, nil
+		}
+		if err := f.resourceMgr.UpdateTechProfileIDForOnu(ctx, intfID, onuID, uniID, TpID); err != nil {
+			logger.Warnw(ctx, "failed-to-update-tech-profile-id", log.Fields{"error": err})
+		}
+	} else {
+		logger.Debugw(ctx, "tech-profile-instance-already-exist-for-given port-name",
+			log.Fields{
+				"uni":       uni,
+				"device-id": f.deviceHandler.device.Id})
+		tpInstanceExists = true
+	}
+
+	switch tpInst := techProfileInstance.(type) {
+	case *tp.TechProfile:
+		if UsMeterID != 0 {
+			sq := schedQueue{direction: tp_pb.Direction_UPSTREAM, intfID: intfID, onuID: onuID, uniID: uniID, tpID: TpID,
+				uniPort: uniPort, tpInst: techProfileInstance, meterID: UsMeterID, flowMetadata: flowMetadata}
+			if err := f.CreateSchedulerQueues(ctx, sq); err != nil {
+				logger.Errorw(ctx, "CreateSchedulerQueues-failed-upstream",
+					log.Fields{
+						"error":     err,
+						"meter-id":  UsMeterID,
+						"device-id": f.deviceHandler.device.Id})
+				return 0, nil, nil
+			}
+		}
+		if DsMeterID != 0 {
+			sq := schedQueue{direction: tp_pb.Direction_DOWNSTREAM, intfID: intfID, onuID: onuID, uniID: uniID, tpID: TpID,
+				uniPort: uniPort, tpInst: techProfileInstance, meterID: DsMeterID, flowMetadata: flowMetadata}
+			if err := f.CreateSchedulerQueues(ctx, sq); err != nil {
+				logger.Errorw(ctx, "CreateSchedulerQueues-failed-downstream",
+					log.Fields{
+						"error":     err,
+						"meter-id":  DsMeterID,
+						"device-id": f.deviceHandler.device.Id})
+				return 0, nil, nil
+			}
+		}
+		allocID := tpInst.UsScheduler.AllocID
+		for _, gem := range tpInst.UpstreamGemPortAttributeList {
+			gemPortIDs = append(gemPortIDs, gem.GemportID)
+		}
+		allocIDs = appendUnique(allocIDs, allocID)
+
+		if tpInstanceExists {
+			return allocID, gemPortIDs, techProfileInstance
+		}
+
+		for _, gemPortID := range gemPortIDs {
+			allgemPortIDs = appendUnique(allgemPortIDs, gemPortID)
+		}
+		logger.Infow(ctx, "allocated-tcont-and-gem-ports",
+			log.Fields{
+				"alloc-ids": allocIDs,
+				"gemports":  allgemPortIDs,
+				"device-id": f.deviceHandler.device.Id})
+		// Send Tconts and GEM ports to KV store
+		f.storeTcontsGEMPortsIntoKVStore(ctx, intfID, onuID, uniID, allocIDs, allgemPortIDs)
+		return allocID, gemPortIDs, techProfileInstance
+	case *tp.EponProfile:
+		// CreateSchedulerQueues for EPON needs to be implemented here
+		// when voltha-protos for EPON is completed.
+
+		// TODO
+		if UsMeterID != 0 {
+			go func() {
+				sq := schedQueue{direction: tp_pb.Direction_UPSTREAM, intfID: intfID, onuID: onuID, uniID: uniID, tpID: TpID,
+					uniPort: uniPort, tpInst: techProfileInstance, meterID: UsMeterID, flowMetadata: flowMetadata}
+				if err := f.L2oamCreateSchedulerQueues(ctx, sq); err != nil {
+					logger.Errorw(ctx, "CreateSchedulerQueues-failed-upstream",
+						log.Fields{
+							"error":     err,
+							"meter-id":  UsMeterID,
+							"device-id": f.deviceHandler.device.Id})
+					//return 0, nil, nil
+				}
+			}()
+		}
+		/*
+			if DsMeterID != 0 {
+					sq := schedQueue{direction: tp_pb.Direction_DOWNSTREAM, intfID: intfID, onuID: onuID, uniID: uniID, tpID: TpID,
+						uniPort: uniPort, tpInst: techProfileInstance, meterID: DsMeterID, flowMetadata: flowMetadata}
+					if err := f.L2oamCreateSchedulerQueues(ctx, sq); err != nil {
+						logger.Errorw(ctx, "CreateSchedulerQueues-failed-downstream",
+							log.Fields{
+								"error":     err,
+								"meter-id":  DsMeterID,
+								"device-id": f.deviceHandler.device.Id})
+						return 0, nil, nil
+					}
+			}
+		*/
+
+		allocID := tpInst.AllocID
+		for _, gem := range tpInst.UpstreamQueueAttributeList {
+			gemPortIDs = append(gemPortIDs, gem.GemportID)
+		}
+		allocIDs = appendUnique(allocIDs, allocID)
+
+		if tpInstanceExists {
+			return allocID, gemPortIDs, techProfileInstance
+		}
+
+		for _, gemPortID := range gemPortIDs {
+			allgemPortIDs = appendUnique(allgemPortIDs, gemPortID)
+		}
+		logger.Infow(ctx, "allocated-tcont-and-gem-ports",
+			log.Fields{
+				"alloc-ids": allocIDs,
+				"gemports":  allgemPortIDs,
+				"device-id": f.deviceHandler.device.Id})
+		// Send Tconts and GEM ports to KV store
+		f.storeTcontsGEMPortsIntoKVStore(ctx, intfID, onuID, uniID, allocIDs, allgemPortIDs)
+		return allocID, gemPortIDs, techProfileInstance
+	default:
+		logger.Errorw(ctx, "unknown-tech",
+			log.Fields{
+				"tpInst": tpInst})
+		return 0, nil, nil
+	}
+}
+
+func (f *OpenOltFlowMgr) storeTcontsGEMPortsIntoKVStore(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, allocID []uint32, gemPortIDs []uint32) {
+
+	logger.Debugw(ctx, "storing-allocated-tconts-and-gem-ports-into-KV-store",
+		log.Fields{
+			"intf-id":     intfID,
+			"onu-id":      onuID,
+			"uni-id":      uniID,
+			"alloc-id":    allocID,
+			"gemport-ids": gemPortIDs,
+			"device-id":   f.deviceHandler.device.Id})
+	/* Update the allocated alloc_id and gem_port_id for the ONU/UNI to KV store  */
+	if err := f.resourceMgr.UpdateAllocIdsForOnu(ctx, intfID, onuID, uniID, allocID); err != nil {
+		logger.Errorw(ctx, "error-while-uploading-allocid-to-kv-store", log.Fields{"device-id": f.deviceHandler.device.Id})
+	}
+	if err := f.resourceMgr.UpdateGEMPortIDsForOnu(ctx, intfID, onuID, uniID, gemPortIDs); err != nil {
+		logger.Errorw(ctx, "error-while-uploading-gemports-to-kv-store", log.Fields{"device-id": f.deviceHandler.device.Id})
+	}
+	if err := f.resourceMgr.UpdateGEMportsPonportToOnuMapOnKVStore(ctx, gemPortIDs, intfID, onuID, uniID); err != nil {
+		logger.Error(ctx, "error-while-uploading-gemtopon-map-to-kv-store", log.Fields{"device-id": f.deviceHandler.device.Id})
+	}
+	logger.Infow(ctx, "stored-tconts-and-gem-into-kv-store-successfully", log.Fields{"device-id": f.deviceHandler.device.Id})
+	for _, gemPort := range gemPortIDs {
+		f.addGemPortToOnuInfoMap(ctx, intfID, onuID, gemPort)
+	}
+}
+
+func (f *OpenOltFlowMgr) populateTechProfilePerPonPort(ctx context.Context) error {
+	var tpCount int
+	for _, techRange := range f.resourceMgr.DevInfo.Ranges {
+		for _, intfID := range techRange.IntfIds {
+			f.techprofile[intfID] = f.resourceMgr.ResourceMgrs[uint32(intfID)].TechProfileMgr
+			tpCount++
+			logger.Debugw(ctx, "init-tech-profile-done",
+				log.Fields{
+					"intf-id":   intfID,
+					"device-id": f.deviceHandler.device.Id})
+		}
+	}
+	if tpCount != int(f.resourceMgr.DevInfo.GetPonPorts()) {
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"reason":             "tP-count-does-not-match-number-of-pon-ports",
+			"tech-profile-count": tpCount,
+			"pon-port-count":     f.resourceMgr.DevInfo.GetPonPorts(),
+			"device-id":          f.deviceHandler.device.Id}, nil)
+	}
+	logger.Infow(ctx, "populated-techprofile-for-ponports-successfully",
+		log.Fields{
+			"numofTech":   tpCount,
+			"numPonPorts": f.resourceMgr.DevInfo.GetPonPorts(),
+			"device-id":   f.deviceHandler.device.Id})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) addUpstreamDataFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32,
+	portNo uint32, uplinkClassifier map[string]interface{},
+	uplinkAction map[string]interface{}, logicalFlow *ofp.OfpFlowStats,
+	allocID uint32, gemportID uint32, tpID uint32) error {
+	uplinkClassifier[PacketTagType] = SingleTag
+	logger.Debugw(ctx, "adding-upstream-data-flow",
+		log.Fields{
+			"uplinkClassifier": uplinkClassifier,
+			"uplinkAction":     uplinkAction})
+	return f.addHSIAFlow(ctx, intfID, onuID, uniID, portNo, uplinkClassifier, uplinkAction,
+		Upstream, logicalFlow, allocID, gemportID, tpID)
+	/* TODO: Install Secondary EAP on the subscriber vlan */
+}
+
+func (f *OpenOltFlowMgr) addDownstreamDataFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32,
+	portNo uint32, downlinkClassifier map[string]interface{},
+	downlinkAction map[string]interface{}, logicalFlow *ofp.OfpFlowStats,
+	allocID uint32, gemportID uint32, tpID uint32) error {
+	downlinkClassifier[PacketTagType] = DoubleTag
+	logger.Debugw(ctx, "adding-downstream-data-flow",
+		log.Fields{
+			"downlinkClassifier": downlinkClassifier,
+			"downlinkAction":     downlinkAction})
+	if vlan, exists := downlinkClassifier[VlanVid]; exists {
+		if vlan.(uint32) == (uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 4000) { //private VLAN given by core
+			if metadata, exists := downlinkClassifier[Metadata]; exists { // inport is filled in metadata by core
+				if uint32(metadata.(uint64)) == MkUniPortNum(ctx, intfID, onuID, uniID) {
+					logger.Infow(ctx, "ignoring-dl-trap-device-flow-from-core",
+						log.Fields{
+							"flow":      logicalFlow,
+							"device-id": f.deviceHandler.device.Id,
+							"onu-id":    onuID,
+							"intf-id":   intfID})
+					return nil
+				}
+			}
+		}
+	}
+
+	/* Already this info available classifier? */
+	downlinkAction[PopVlan] = true
+	dlClVid, ok := downlinkClassifier[VlanVid].(uint32)
+	if ok {
+		downlinkAction[VlanVid] = dlClVid & 0xfff
+	} else {
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"reason":    "failed-to-convert-vlanid-classifier",
+			"vlan-id":   VlanVid,
+			"device-id": f.deviceHandler.device.Id}, nil).Log()
+	}
+
+	return f.addHSIAFlow(ctx, intfID, onuID, uniID, portNo, downlinkClassifier, downlinkAction,
+		Downstream, logicalFlow, allocID, gemportID, tpID)
+}
+
+func (f *OpenOltFlowMgr) addHSIAFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32, classifier map[string]interface{},
+	action map[string]interface{}, direction string, logicalFlow *ofp.OfpFlowStats,
+	allocID uint32, gemPortID uint32, tpID uint32) error {
+	/* One of the OLT platform (Broadcom BAL) requires that symmetric
+	   flows require the same flow_id to be used across UL and DL.
+	   Since HSIA flow is the only symmetric flow currently, we need to
+	   re-use the flow_id across both direction. The 'flow_category'
+	   takes priority over flow_cookie to find any available HSIA_FLOW
+	   id for the ONU.
+	*/
+	logger.Infow(ctx, "adding-hsia-flow",
+		log.Fields{
+			"intf-id":     intfID,
+			"onu-id":      onuID,
+			"uni-id":      uniID,
+			"device-id":   f.deviceHandler.device.Id,
+			"classifier":  classifier,
+			"action":      action,
+			"direction":   direction,
+			"alloc-id":    allocID,
+			"gemport-id":  gemPortID,
+			"logicalflow": *logicalFlow})
+	var vlanPbit uint32 = 0xff // means no pbit
+	var vlanVid uint32
+	if _, ok := classifier[VlanPcp]; ok {
+		vlanPbit = classifier[VlanPcp].(uint32)
+		logger.Debugw(ctx, "found-pbit-in-flow",
+			log.Fields{
+				"vlan-pbit": vlanPbit,
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"device-id": f.deviceHandler.device.Id})
+	} else {
+		logger.Debugw(ctx, "pbit-not-found-in-flow",
+			log.Fields{
+				"vlan-pcp":  VlanPcp,
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"device-id": f.deviceHandler.device.Id})
+	}
+	if _, ok := classifier[VlanVid]; ok {
+		vlanVid = classifier[VlanVid].(uint32)
+		logger.Debugw(ctx, "found-vlan-in-the-flow",
+			log.Fields{
+				"vlan-vid":  vlanVid,
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"device-id": f.deviceHandler.device.Id})
+	}
+	flowStoreCookie := getFlowStoreCookie(ctx, classifier, gemPortID)
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(intfID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "flow-already-exists",
+			log.Fields{
+				"device-id": f.deviceHandler.device.Id,
+				"intf-id":   intfID,
+				"onu-id":    onuID})
+		return nil
+	}
+	flowID, err := f.resourceMgr.GetFlowID(ctx, intfID, int32(onuID), int32(uniID), gemPortID, flowStoreCookie, HsiaFlow, vlanVid, vlanPbit)
+	if err != nil {
+		return olterrors.NewErrNotFound("hsia-flow-id",
+			log.Fields{
+				"direction": direction,
+				"device-id": f.deviceHandler.device.Id,
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+			}, err).Log()
+	}
+	classifierProto, err := makeOpenOltClassifierField(classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifier, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Debugw(ctx, "created-classifier-proto",
+		log.Fields{
+			"classifier": *classifierProto,
+			"device-id":  f.deviceHandler.device.Id})
+	actionProto, err := makeOpenOltActionField(action, classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": action, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Debugw(ctx, "created-action-proto",
+		log.Fields{
+			"action":    *actionProto,
+			"device-id": f.deviceHandler.device.Id})
+	networkIntfID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-interface-id",
+			log.Fields{
+				"classifier": classifier,
+				"action":     action,
+				"device-id":  f.deviceHandler.device.Id,
+			}, err).Log()
+	}
+	flow := openoltpb2.Flow{AccessIntfId: int32(intfID),
+		OnuId:         int32(onuID),
+		UniId:         int32(uniID),
+		FlowId:        flowID,
+		FlowType:      direction,
+		AllocId:       int32(allocID),
+		NetworkIntfId: int32(networkIntfID),
+		GemportId:     int32(gemPortID),
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo,
+		TechProfileId: tpID,
+	}
+	if err := f.addFlowToDevice(ctx, logicalFlow, &flow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, nil, err).Log()
+	}
+	logger.Infow(ctx, "hsia-flow-added-to-device-successfully",
+		log.Fields{"direction": direction,
+			"device-id": f.deviceHandler.device.Id,
+			"flow":      flow,
+			"intf-id":   intfID,
+			"onu-id":    onuID})
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &flow, flowStoreCookie, HsiaFlow, flowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, flow.AccessIntfId,
+		flow.OnuId,
+		flow.UniId,
+		flow.FlowId /*flowCategory,*/, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flowID,
+			log.Fields{
+				"flow":      flow,
+				"device-id": f.deviceHandler.device.Id,
+				"intf-id":   intfID,
+				"onu-id":    onuID}, err).Log()
+	}
+
+	go f.l2oamAddFlowDevice(ctx, intfID, onuID, classifierProto.OVid, classifierProto.IVid)
+
+	return nil
+}
+
+func (f *OpenOltFlowMgr) addDHCPTrapFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32,
+	classifier map[string]interface{}, action map[string]interface{}, logicalFlow *ofp.OfpFlowStats, allocID uint32,
+	gemPortID uint32, tpID uint32) error {
+
+	networkIntfID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-interface-id", log.Fields{
+			"classifier": classifier,
+			"action":     action,
+			"device-id":  f.deviceHandler.device.Id},
+			err).Log()
+	}
+
+	for k := range action {
+		delete(action, k)
+	}
+
+	action[TrapToHost] = true
+	classifier[UDPSrc] = uint32(68)
+	classifier[UDPDst] = uint32(67)
+	classifier[PacketTagType] = SingleTag
+
+	flowStoreCookie := getFlowStoreCookie(ctx, classifier, gemPortID)
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(intfID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "flow-exists--not-re-adding",
+			log.Fields{
+				"device-id": f.deviceHandler.device.Id,
+				"intf-id":   intfID,
+				"onu-id":    onuID})
+		return nil
+	}
+
+	flowID, err := f.resourceMgr.GetFlowID(ctx, intfID, int32(onuID), int32(uniID), gemPortID, flowStoreCookie, DhcpFlow, 0 /*classifier[VLAN_PCP].(uint32)*/)
+
+	if err != nil {
+		return olterrors.NewErrNotFound("flow",
+			log.Fields{
+				"interface-id": intfID,
+				"gem-port":     gemPortID,
+				"cookie":       flowStoreCookie,
+				"device-id":    f.deviceHandler.device.Id},
+			err).Log()
+	}
+
+	logger.Debugw(ctx, "creating-ul-dhcp-flow",
+		log.Fields{
+			"ul_classifier": classifier,
+			"ul_action":     action,
+			"uplinkFlowId":  flowID,
+			"intf-id":       intfID,
+			"onu-id":        onuID,
+			"device-id":     f.deviceHandler.device.Id})
+
+	classifierProto, err := makeOpenOltClassifierField(classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifier}, err).Log()
+	}
+	logger.Debugw(ctx, "created-classifier-proto", log.Fields{"classifier": *classifierProto})
+	actionProto, err := makeOpenOltActionField(action, classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": action}, err).Log()
+	}
+
+	dhcpFlow := openoltpb2.Flow{AccessIntfId: int32(intfID),
+		OnuId:         int32(onuID),
+		UniId:         int32(uniID),
+		FlowId:        flowID,
+		FlowType:      Upstream,
+		AllocId:       int32(allocID),
+		NetworkIntfId: int32(networkIntfID),
+		GemportId:     int32(gemPortID),
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo,
+		TechProfileId: tpID,
+	}
+	if err := f.addFlowToDevice(ctx, logicalFlow, &dhcpFlow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, log.Fields{"dhcp-flow": dhcpFlow}, err).Log()
+	}
+	logger.Infow(ctx, "dhcp-ul-flow-added-to-device-successfully",
+		log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"flow-id":   flowID,
+			"intf-id":   intfID,
+			"onu-id":    onuID})
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &dhcpFlow, flowStoreCookie, "DHCP", flowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, dhcpFlow.AccessIntfId,
+		dhcpFlow.OnuId,
+		dhcpFlow.UniId,
+		dhcpFlow.FlowId, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", dhcpFlow.FlowId,
+			log.Fields{
+				"flow":      dhcpFlow,
+				"device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+
+	return nil
+}
+
+//addIGMPTrapFlow creates IGMP trap-to-host flow
+func (f *OpenOltFlowMgr) addIGMPTrapFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32, classifier map[string]interface{},
+	action map[string]interface{}, logicalFlow *ofp.OfpFlowStats, allocID uint32, gemPortID uint32, tpID uint32) error {
+	return f.addUpstreamTrapFlow(ctx, intfID, onuID, uniID, portNo, classifier, action, logicalFlow, allocID, gemPortID, IgmpFlow, tpID)
+}
+
+//addUpstreamTrapFlow creates a trap-to-host flow
+func (f *OpenOltFlowMgr) addUpstreamTrapFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32, classifier map[string]interface{},
+	action map[string]interface{}, logicalFlow *ofp.OfpFlowStats, allocID uint32, gemPortID uint32, flowType string, tpID uint32) error {
+
+	networkIntfID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-interface-id",
+			log.Fields{
+				"classifier": classifier,
+				"action":     action,
+				"device-id":  f.deviceHandler.device.Id},
+			err).Log()
+	}
+
+	for k := range action {
+		delete(action, k)
+	}
+
+	action[TrapToHost] = true
+	classifier[PacketTagType] = SingleTag
+	delete(classifier, VlanVid)
+
+	flowStoreCookie := getFlowStoreCookie(ctx, classifier, gemPortID)
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(networkIntfID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "flow-exists-not-re-adding", log.Fields{"device-id": f.deviceHandler.device.Id})
+		return nil
+	}
+
+	flowID, err := f.resourceMgr.GetFlowID(ctx, intfID, int32(onuID), int32(uniID), gemPortID, flowStoreCookie, flowType, 0, 0 /*classifier[VLAN_PCP].(uint32)*/)
+
+	if err != nil {
+		return olterrors.NewErrNotFound("flow-id",
+			log.Fields{
+				"intf-id":   intfID,
+				"oni-id":    onuID,
+				"cookie":    flowStoreCookie,
+				"flow-type": flowType,
+				"device-id": f.deviceHandler.device.Id,
+				"onu-id":    onuID},
+			err).Log()
+	}
+
+	logger.Debugw(ctx, "creating-upstream-trap-flow",
+		log.Fields{
+			"ul_classifier": classifier,
+			"ul_action":     action,
+			"uplinkFlowId":  flowID,
+			"flowType":      flowType,
+			"device-id":     f.deviceHandler.device.Id,
+			"intf-id":       intfID,
+			"onu-id":        onuID})
+
+	classifierProto, err := makeOpenOltClassifierField(classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifier, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Debugw(ctx, "created-classifier-proto",
+		log.Fields{
+			"classifier": *classifierProto,
+			"device-id":  f.deviceHandler.device.Id})
+	actionProto, err := makeOpenOltActionField(action, classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": action, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+
+	flow := openoltpb2.Flow{AccessIntfId: int32(intfID),
+		OnuId:         int32(onuID),
+		UniId:         int32(uniID),
+		FlowId:        flowID,
+		FlowType:      Upstream,
+		AllocId:       int32(allocID),
+		NetworkIntfId: int32(networkIntfID),
+		GemportId:     int32(gemPortID),
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo,
+		TechProfileId: tpID,
+	}
+
+	if err := f.addFlowToDevice(ctx, logicalFlow, &flow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, log.Fields{"flow": flow, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Infof(ctx, "%s ul-flow-added-to-device-successfully", flowType)
+
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &flow, flowStoreCookie, flowType, flowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, flow.AccessIntfId,
+		flow.OnuId,
+		flow.UniId,
+		flow.FlowId, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flow.FlowId, log.Fields{"flow": flow, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+
+	return nil
+}
+
+// Add EAPOL flow to  device with mac, vlanId as classifier for upstream and downstream
+func (f *OpenOltFlowMgr) addEAPOLFlow(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, portNo uint32,
+	classifier map[string]interface{}, action map[string]interface{}, logicalFlow *ofp.OfpFlowStats, allocID uint32,
+	gemPortID uint32, vlanID uint32, tpID uint32) error {
+	logger.Infow(ctx, "adding-eapol-to-device",
+		log.Fields{
+			"intf-id":    intfID,
+			"onu-id":     onuID,
+			"port-no":    portNo,
+			"alloc-id":   allocID,
+			"gemport-id": gemPortID,
+			"vlan-id":    vlanID,
+			"flow":       logicalFlow})
+
+	uplinkClassifier := make(map[string]interface{})
+	uplinkAction := make(map[string]interface{})
+
+	uplinkClassifier[EthType] = uint32(EapEthType)
+	uplinkClassifier[PacketTagType] = SingleTag
+	uplinkClassifier[VlanVid] = vlanID
+	uplinkClassifier[VlanPcp] = classifier[VlanPcp]
+	uplinkAction[TrapToHost] = true
+	flowStoreCookie := getFlowStoreCookie(ctx, uplinkClassifier, gemPortID)
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(intfID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "flow-exists-not-re-adding", log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"onu-id":    onuID,
+			"intf-id":   intfID})
+		return nil
+	}
+	uplinkFlowID, err := f.resourceMgr.GetFlowID(ctx, intfID, int32(onuID), int32(uniID), gemPortID, flowStoreCookie, "", 0, 0)
+	if err != nil {
+		return olterrors.NewErrNotFound("flow-id",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"coookie":   flowStoreCookie,
+				"device-id": f.deviceHandler.device.Id},
+			err).Log()
+	}
+	logger.Debugw(ctx, "creating-ul-eapol-flow",
+		log.Fields{
+			"ul_classifier": uplinkClassifier,
+			"ul_action":     uplinkAction,
+			"uplinkFlowId":  uplinkFlowID,
+			"device-id":     f.deviceHandler.device.Id,
+			"intf-id":       intfID,
+			"onu-id":        onuID})
+
+	classifierProto, err := makeOpenOltClassifierField(uplinkClassifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"classifier": uplinkClassifier,
+			"device-id":  f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Debugw(ctx, "created-classifier-proto",
+		log.Fields{
+			"classifier": *classifierProto,
+			"device-id":  f.deviceHandler.device.Id})
+	actionProto, err := makeOpenOltActionField(uplinkAction, uplinkClassifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": uplinkAction, "device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	logger.Debugw(ctx, "created-action-proto",
+		log.Fields{
+			"action":    *actionProto,
+			"device-id": f.deviceHandler.device.Id})
+	networkIntfID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-interface-id", log.Fields{
+			"classifier": classifier,
+			"action":     action,
+			"device-id":  f.deviceHandler.device.Id},
+			err).Log()
+	}
+
+	upstreamFlow := openoltpb2.Flow{AccessIntfId: int32(intfID),
+		OnuId:         int32(onuID),
+		UniId:         int32(uniID),
+		FlowId:        uplinkFlowID,
+		FlowType:      Upstream,
+		AllocId:       int32(allocID),
+		NetworkIntfId: int32(networkIntfID),
+		GemportId:     int32(gemPortID),
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo,
+		TechProfileId: tpID,
+	}
+	if err := f.addFlowToDevice(ctx, logicalFlow, &upstreamFlow); err != nil {
+		return olterrors.NewErrFlowOp("add", uplinkFlowID, log.Fields{"flow": upstreamFlow}, err).Log()
+	}
+	logger.Infow(ctx, "eapol-ul-flow-added-to-device-successfully",
+		log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"onu-id":    onuID,
+			"intf-id":   intfID,
+		})
+	flowCategory := "EAPOL"
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &upstreamFlow, flowStoreCookie, flowCategory, uplinkFlowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, upstreamFlow.AccessIntfId,
+		upstreamFlow.OnuId,
+		upstreamFlow.UniId,
+		upstreamFlow.FlowId,
+		/* lowCategory, */
+		flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", upstreamFlow.FlowId,
+			log.Fields{
+				"flow":      upstreamFlow,
+				"device-id": f.deviceHandler.device.Id}, err).Log()
+	}
+	return nil
+}
+
+func makeOpenOltClassifierField(classifierInfo map[string]interface{}) (*openoltpb2.Classifier, error) {
+	var classifier openoltpb2.Classifier
+
+	classifier.EthType, _ = classifierInfo[EthType].(uint32)
+	classifier.IpProto, _ = classifierInfo[IPProto].(uint32)
+	if vlanID, ok := classifierInfo[VlanVid].(uint32); ok {
+		if vlanID != ReservedVlan {
+			vid := vlanID & VlanvIDMask
+			classifier.OVid = vid
+		}
+	}
+	if metadata, ok := classifierInfo[Metadata].(uint64); ok {
+		vid := uint32(metadata)
+		if vid != ReservedVlan {
+			classifier.IVid = vid
+		}
+	}
+	if vlanPcp, ok := classifierInfo[VlanPcp].(uint32); ok {
+		classifier.OPbits = vlanPcp
+	} else {
+		classifier.OPbits = VlanPCPMask
+	}
+	classifier.SrcPort, _ = classifierInfo[UDPSrc].(uint32)
+	classifier.DstPort, _ = classifierInfo[UDPDst].(uint32)
+	classifier.DstIp, _ = classifierInfo[Ipv4Dst].(uint32)
+	classifier.SrcIp, _ = classifierInfo[Ipv4Src].(uint32)
+	classifier.DstMac, _ = classifierInfo[EthDst].([]uint8)
+	if pktTagType, ok := classifierInfo[PacketTagType].(string); ok {
+		classifier.PktTagType = pktTagType
+
+		switch pktTagType {
+		case SingleTag:
+		case DoubleTag:
+		case Untagged:
+		default:
+			return nil, olterrors.NewErrInvalidValue(log.Fields{"packet-tag-type": pktTagType}, nil)
+		}
+	}
+	return &classifier, nil
+}
+
+func makeOpenOltActionField(actionInfo map[string]interface{}, classifierInfo map[string]interface{}) (*openoltpb2.Action, error) {
+	var actionCmd openoltpb2.ActionCmd
+	var action openoltpb2.Action
+	action.Cmd = &actionCmd
+	if _, ok := actionInfo[PopVlan]; ok {
+		action.Cmd.RemoveOuterTag = true
+		if _, ok := actionInfo[VlanPcp]; ok {
+			action.Cmd.RemarkInnerPbits = true
+			action.IPbits = actionInfo[VlanPcp].(uint32)
+			if _, ok := actionInfo[VlanVid]; ok {
+				action.Cmd.TranslateInnerTag = true
+				action.IVid = actionInfo[VlanVid].(uint32)
+			}
+		}
+	} else if _, ok := actionInfo[PushVlan]; ok {
+		action.OVid = actionInfo[VlanVid].(uint32)
+		action.Cmd.AddOuterTag = true
+		if _, ok := actionInfo[VlanPcp]; ok {
+			action.OPbits = actionInfo[VlanPcp].(uint32)
+			action.Cmd.RemarkOuterPbits = true
+			if _, ok := classifierInfo[VlanVid]; ok {
+				action.IVid = classifierInfo[VlanVid].(uint32)
+				action.Cmd.TranslateInnerTag = true
+			}
+		}
+	} else if _, ok := actionInfo[TrapToHost]; ok {
+		action.Cmd.TrapToHost = actionInfo[TrapToHost].(bool)
+	} else {
+		return nil, olterrors.NewErrInvalidValue(log.Fields{"action-command": actionInfo}, nil)
+	}
+	return &action, nil
+}
+
+// getTPpath return the ETCD path for a given UNI port
+func (f *OpenOltFlowMgr) getTPpath(ctx context.Context, intfID uint32, uniPath string, TpID uint32) string {
+	return f.techprofile[intfID].GetTechProfileInstanceKVPath(ctx, TpID, uniPath)
+}
+
+// DeleteTechProfileInstances removes the tech profile instances from persistent storage
+func (f *OpenOltFlowMgr) DeleteTechProfileInstances(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, sn string) error {
+	tpIDList := f.resourceMgr.GetTechProfileIDForOnu(ctx, intfID, onuID, uniID)
+	uniPortName := getUniPortPath(f.deviceHandler.device.Id, intfID, int32(onuID), int32(uniID))
+
+	for _, tpID := range tpIDList {
+		if err := f.DeleteTechProfileInstance(ctx, intfID, onuID, uniID, uniPortName, tpID); err != nil {
+			_ = olterrors.NewErrAdapter("delete-tech-profile-failed", log.Fields{"device-id": f.deviceHandler.device.Id}, err).Log()
+			// return err
+			// We should continue to delete tech-profile instances for other TP IDs
+		}
+		logger.Debugw(ctx, "tech-profile-deleted", log.Fields{"device-id": f.deviceHandler.device.Id, "tp-id": tpID})
+	}
+	return nil
+}
+
+// DeleteTechProfileInstance removes the tech profile instance from persistent storage
+func (f *OpenOltFlowMgr) DeleteTechProfileInstance(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, uniPortName string, tpID uint32) error {
+	if uniPortName == "" {
+		uniPortName = getUniPortPath(f.deviceHandler.device.Id, intfID, int32(onuID), int32(uniID))
+	}
+	if err := f.techprofile[intfID].DeleteTechProfileInstance(ctx, tpID, uniPortName); err != nil {
+		return olterrors.NewErrAdapter("failed-to-delete-tp-instance-from-kv-store",
+			log.Fields{
+				"tp-id":         tpID,
+				"uni-port-name": uniPortName,
+				"device-id":     f.deviceHandler.device.Id}, err)
+	}
+	return nil
+}
+
+func getFlowStoreCookie(ctx context.Context, classifier map[string]interface{}, gemPortID uint32) uint64 {
+	if len(classifier) == 0 { // should never happen
+		logger.Error(ctx, "invalid-classfier-object")
+		return 0
+	}
+	logger.Debugw(ctx, "generating-flow-store-cookie",
+		log.Fields{
+			"classifier": classifier,
+			"gemport-id": gemPortID})
+	var jsonData []byte
+	var flowString string
+	var err error
+	if jsonData, err = json.Marshal(classifier); err != nil {
+		logger.Error(ctx, "failed-to-encode-classifier")
+		return 0
+	}
+	flowString = string(jsonData)
+	if gemPortID != 0 {
+		flowString = fmt.Sprintf("%s%s", string(jsonData), string(gemPortID))
+	}
+	h := md5.New()
+	_, _ = h.Write([]byte(flowString))
+	hash := big.NewInt(0)
+	hash.SetBytes(h.Sum(nil))
+	generatedHash := hash.Uint64()
+	logger.Debugw(ctx, "hash-generated", log.Fields{"hash": generatedHash})
+	return generatedHash
+}
+
+func (f *OpenOltFlowMgr) getUpdatedFlowInfo(ctx context.Context, flow *openoltpb2.Flow, flowStoreCookie uint64, flowCategory string, deviceFlowID uint32, logicalFlowID uint64) *[]rsrcMgr.FlowInfo {
+	var flows = []rsrcMgr.FlowInfo{{Flow: flow, FlowCategory: flowCategory, FlowStoreCookie: flowStoreCookie, LogicalFlowID: logicalFlowID}}
+	var intfID uint32
+	/* For flows which trap out of the NNI, the AccessIntfId is invalid
+	   (set to -1). In such cases, we need to refer to the NetworkIntfId .
+	*/
+	if flow.AccessIntfId != -1 {
+		intfID = uint32(flow.AccessIntfId)
+	} else {
+		intfID = uint32(flow.NetworkIntfId)
+	}
+	existingFlows := f.resourceMgr.GetFlowIDInfo(ctx, intfID, flow.OnuId, flow.UniId, flow.FlowId)
+	if existingFlows != nil {
+		logger.Debugw(ctx, "flow-exists-for-given-flowID--appending-it-to-current-flow",
+			log.Fields{
+				"flow-id":   flow.FlowId,
+				"device-id": f.deviceHandler.device.Id,
+				"intf-id":   intfID,
+				"onu-id":    flow.OnuId})
+		//for _, f := range *existingFlows {
+		//	flows = append(flows, f)
+		//}
+		flows = append(flows, *existingFlows...)
+	}
+	logger.Debugw(ctx, "updated-flows-for-given-flowID-and-onuid",
+		log.Fields{
+			"updatedflow": flows,
+			"flow-id":     flow.FlowId,
+			"onu-id":      flow.OnuId,
+			"device-id":   f.deviceHandler.device.Id})
+	return &flows
+}
+
+func (f *OpenOltFlowMgr) updateFlowInfoToKVStore(ctx context.Context, intfID int32, onuID int32, uniID int32, flowID uint32, flows *[]rsrcMgr.FlowInfo) error {
+	logger.Debugw(ctx, "storing-flow(s)-into-kv-store", log.Fields{
+		"flow-id":   flowID,
+		"device-id": f.deviceHandler.device.Id,
+		"intf-id":   intfID,
+		"onu-id":    onuID})
+	if err := f.resourceMgr.UpdateFlowIDInfo(ctx, intfID, onuID, uniID, flowID, flows); err != nil {
+		logger.Warnw(ctx, "error-while-storing-flow-into-kv-store", log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"onu-id":    onuID,
+			"intf-id":   intfID,
+			"flow-id":   flowID})
+		return err
+	}
+	logger.Infow(ctx, "stored-flow(s)-into-kv-store-successfully!", log.Fields{
+		"device-id": f.deviceHandler.device.Id,
+		"onu-id":    onuID,
+		"intf-id":   intfID,
+		"flow-id":   flowID})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) addFlowToDevice(ctx context.Context, logicalFlow *ofp.OfpFlowStats, deviceFlow *openoltpb2.Flow) error {
+
+	var intfID uint32
+	/* For flows which trap out of the NNI, the AccessIntfId is invalid
+	   (set to -1). In such cases, we need to refer to the NetworkIntfId .
+	*/
+	if deviceFlow.AccessIntfId != -1 {
+		intfID = uint32(deviceFlow.AccessIntfId)
+	} else {
+		// REVIST : Why ponport is given as network port?
+		intfID = uint32(deviceFlow.NetworkIntfId)
+	}
+
+	logger.Debugw(ctx, "sending-flow-to-device-via-grpc", log.Fields{
+		"flow":      *deviceFlow,
+		"device-id": f.deviceHandler.device.Id,
+		"intf-id":   intfID})
+	_, err := f.deviceHandler.Client.FlowAdd(log.WithSpanFromContext(context.Background(), ctx), deviceFlow)
+
+	st, _ := status.FromError(err)
+	if st.Code() == codes.AlreadyExists {
+		logger.Debug(ctx, "flow-already-exists", log.Fields{
+			"err":        err,
+			"deviceFlow": deviceFlow,
+			"device-id":  f.deviceHandler.device.Id,
+			"intf-id":    intfID})
+		return nil
+	}
+
+	if err != nil {
+		logger.Errorw(ctx, "failed-to-add-flow-to-device",
+			log.Fields{"err": err,
+				"device-flow": deviceFlow,
+				"device-id":   f.deviceHandler.device.Id,
+				"intf-id":     intfID})
+		f.resourceMgr.FreeFlowID(ctx, intfID, deviceFlow.OnuId, deviceFlow.UniId, deviceFlow.FlowId)
+		return err
+	}
+	if deviceFlow.GemportId != -1 {
+		// No need to register the flow if it is a trap on nni flow.
+		if err := f.registerFlow(ctx, logicalFlow, deviceFlow); err != nil {
+			logger.Errorw(ctx, "failed-to-register-flow", log.Fields{"err": err})
+			return err
+		}
+	}
+	logger.Infow(ctx, "flow-added-to-device-successfully ",
+		log.Fields{
+			"flow":      *deviceFlow,
+			"device-id": f.deviceHandler.device.Id,
+			"intf-id":   intfID})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) removeFlowFromDevice(ctx context.Context, deviceFlow *openoltpb2.Flow, ofFlowID uint64) error {
+	logger.Debugw(ctx, "sending-flow-to-device-via-grpc",
+		log.Fields{
+			"flow":      *deviceFlow,
+			"device-id": f.deviceHandler.device.Id})
+	_, err := f.deviceHandler.Client.FlowRemove(log.WithSpanFromContext(context.Background(), ctx), deviceFlow)
+	if err != nil {
+		if f.deviceHandler.device.ConnectStatus == common.ConnectStatus_UNREACHABLE {
+			logger.Warnw(ctx, "can-not-remove-flow-from-device--unreachable",
+				log.Fields{
+					"err":        err,
+					"deviceFlow": deviceFlow,
+					"device-id":  f.deviceHandler.device.Id})
+			//Assume the flow is removed
+			return nil
+		}
+		return olterrors.NewErrFlowOp("remove", deviceFlow.FlowId, log.Fields{"deviceFlow": deviceFlow}, err)
+
+	}
+	logger.Infow(ctx, "flow-removed-from-device-successfully", log.Fields{
+		"of-flow-id": ofFlowID,
+		"flow":       *deviceFlow,
+		"device-id":  f.deviceHandler.device.Id,
+	})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) addLLDPFlow(ctx context.Context, flow *ofp.OfpFlowStats, portNo uint32) error {
+
+	classifierInfo := make(map[string]interface{})
+	actionInfo := make(map[string]interface{})
+
+	classifierInfo[EthType] = uint32(LldpEthType)
+	classifierInfo[PacketTagType] = Untagged
+	actionInfo[TrapToHost] = true
+
+
+	var onuID = -1
+	var uniID = -1
+	var gemPortID = -1
+
+	networkInterfaceID, err := IntfIDFromNniPortNum(ctx, portNo)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"nni-port-number": portNo}, err).Log()
+	}
+	var flowStoreCookie = getFlowStoreCookie(ctx, classifierInfo, uint32(0))
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "flow-exists--not-re-adding", log.Fields{"device-id": f.deviceHandler.device.Id})
+		return nil
+	}
+	flowID, err := f.resourceMgr.GetFlowID(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), uint32(gemPortID), flowStoreCookie, "", 0)
+
+	if err != nil {
+		return olterrors.NewErrNotFound("flow-id",
+			log.Fields{
+				"interface-id": networkInterfaceID,
+				"onu-id":       onuID,
+				"uni-id":       uniID,
+				"gem-port-id":  gemPortID,
+				"cookie":       flowStoreCookie,
+				"device-id":    f.deviceHandler.device.Id},
+			err)
+	}
+	classifierProto, err := makeOpenOltClassifierField(classifierInfo)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(
+			log.Fields{
+				"classifier": classifierInfo,
+				"device-id":  f.deviceHandler.device.Id}, err)
+	}
+	logger.Debugw(ctx, "created-classifier-proto",
+		log.Fields{
+			"classifier": *classifierProto,
+			"device-id":  f.deviceHandler.device.Id})
+	actionProto, err := makeOpenOltActionField(actionInfo, classifierInfo)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(
+			log.Fields{
+				"action":    actionInfo,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	logger.Debugw(ctx, "created-action-proto",
+		log.Fields{
+			"action":    *actionProto,
+			"device-id": f.deviceHandler.device.Id})
+
+	downstreamflow := openoltpb2.Flow{AccessIntfId: int32(-1), // AccessIntfId not required
+		OnuId:         int32(onuID), // OnuId not required
+		UniId:         int32(uniID), // UniId not used
+		FlowId:        flowID,
+		FlowType:      Downstream,
+		NetworkIntfId: int32(networkInterfaceID),
+		GemportId:     int32(gemPortID),
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(flow.Priority),
+		Cookie:        flow.Cookie,
+		PortNo:        portNo}
+	if err := f.addFlowToDevice(ctx, flow, &downstreamflow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID,
+			log.Fields{
+				"flow":      downstreamflow,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	logger.Infow(ctx, "lldp-trap-on-nni-flow-added-to-device-successfully",
+		log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"onu-id":    onuID,
+			"flow-id":   flowID})
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &downstreamflow, flowStoreCookie, "", flowID, flow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, int32(networkInterfaceID),
+		int32(onuID),
+		int32(uniID),
+		flowID, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flowID,
+			log.Fields{
+				"flow":      downstreamflow,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+	return nil
+}
+
+func getUniPortPath(oltID string, intfID uint32, onuID int32, uniID int32) string {
+	return fmt.Sprintf("olt-{%s}/pon-{%d}/onu-{%d}/uni-{%d}", oltID, intfID, onuID, uniID)
+}
+
+//getOnuDevice to fetch onu from cache or core.
+func (f *OpenOltFlowMgr) getOnuDevice(ctx context.Context, intfID uint32, onuID uint32) (*OnuDevice, error) {
+	onuKey := f.deviceHandler.formOnuKey(intfID, onuID)
+	onuDev, ok := f.deviceHandler.onus.Load(onuKey)
+	if !ok {
+		logger.Debugw(ctx, "couldnt-find-onu-in-cache",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"device-id": f.deviceHandler.device.Id})
+		onuDevice, err := f.getChildDevice(ctx, intfID, onuID)
+		if err != nil {
+			return nil, olterrors.NewErrNotFound("onu-child-device",
+				log.Fields{
+					"onu-id":    onuID,
+					"intf-id":   intfID,
+					"device-id": f.deviceHandler.device.Id}, err)
+		}
+		onuDev = NewOnuDevice(onuDevice.Id, onuDevice.Type, onuDevice.SerialNumber, onuDevice.ProxyAddress.OnuId, onuDevice.ProxyAddress.ChannelId, onuDevice.ProxyAddress.DeviceId, false)
+		//better to ad the device to cache here.
+		f.deviceHandler.StoreOnuDevice(onuDev.(*OnuDevice))
+	} else {
+		logger.Debugw(ctx, "found-onu-in-cache",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"device-id": f.deviceHandler.device.Id})
+	}
+
+	return onuDev.(*OnuDevice), nil
+}
+
+//getChildDevice to fetch onu
+func (f *OpenOltFlowMgr) getChildDevice(ctx context.Context, intfID uint32, onuID uint32) (*voltha.Device, error) {
+	logger.Infow(ctx, "GetChildDevice",
+		log.Fields{
+			"pon-port":  intfID,
+			"onu-id":    onuID,
+			"device-id": f.deviceHandler.device.Id})
+	parentPortNo := IntfIDToPortNo(intfID, voltha.Port_PON_OLT)
+	onuDevice, err := f.deviceHandler.GetChildDevice(ctx, parentPortNo, onuID)
+	if err != nil {
+		return nil, olterrors.NewErrNotFound("onu",
+			log.Fields{
+				"interface-id": parentPortNo,
+				"onu-id":       onuID,
+				"device-id":    f.deviceHandler.device.Id},
+			err)
+	}
+	logger.Infow(ctx, "successfully-received-child-device-from-core",
+		log.Fields{
+			"device-id":       f.deviceHandler.device.Id,
+			"child_device_id": onuDevice.Id,
+			"child_device_sn": onuDevice.SerialNumber})
+	return onuDevice, nil
+}
+
+func (f *OpenOltFlowMgr) sendDeleteGemPortToChild(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, gemPortID uint32, tpPath string) error {
+	onuDev, err := f.getOnuDevice(ctx, intfID, onuID)
+	if err != nil {
+		logger.Debugw(ctx, "couldnt-find-onu-child-device",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"uni-id":    uniID,
+				"device-id": f.deviceHandler.device.Id})
+		return err
+	}
+
+	delGemPortMsg := &ic.InterAdapterDeleteGemPortMessage{UniId: uniID, TpPath: tpPath, GemPortId: gemPortID}
+	logger.Debugw(ctx, "sending-gem-port-delete-to-openonu-adapter",
+		log.Fields{
+			"msg":       *delGemPortMsg,
+			"device-id": f.deviceHandler.device.Id})
+	if sendErr := f.deviceHandler.AdapterProxy.SendInterAdapterMessage(log.WithSpanFromContext(context.Background(), ctx),
+		delGemPortMsg,
+		ic.InterAdapterMessageType_DELETE_GEM_PORT_REQUEST,
+		f.deviceHandler.device.Type,
+		onuDev.deviceType,
+		onuDev.deviceID,
+		onuDev.proxyDeviceID, ""); sendErr != nil {
+		return olterrors.NewErrCommunication("send-delete-gem-port-to-onu-adapter",
+			log.Fields{
+				"from-adapter":  f.deviceHandler.device.Type,
+				"to-adapter":    onuDev.deviceType,
+				"onu-id":        onuDev.deviceID,
+				"proxyDeviceID": onuDev.proxyDeviceID,
+				"device-id":     f.deviceHandler.device.Id}, sendErr)
+	}
+	logger.Infow(ctx, "success-sending-del-gem-port-to-onu-adapter",
+		log.Fields{
+			"msg":          delGemPortMsg,
+			"from-adapter": f.deviceHandler.device.Type,
+			"to-adapter":   onuDev.deviceType,
+			"device-id":    f.deviceHandler.device.Id})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) sendDeleteTcontToChild(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, allocID uint32, tpPath string) error {
+	onuDev, err := f.getOnuDevice(ctx, intfID, onuID)
+	if err != nil {
+		logger.Warnw(ctx, "couldnt-find-onu-child-device",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"uni-id":    uniID,
+				"device-id": f.deviceHandler.device.Id})
+		return err
+	}
+
+	delTcontMsg := &ic.InterAdapterDeleteTcontMessage{UniId: uniID, TpPath: tpPath, AllocId: allocID}
+	logger.Debugw(ctx, "sending-tcont-delete-to-openonu-adapter",
+		log.Fields{
+			"msg":       *delTcontMsg,
+			"device-id": f.deviceHandler.device.Id})
+	if sendErr := f.deviceHandler.AdapterProxy.SendInterAdapterMessage(log.WithSpanFromContext(context.Background(), ctx),
+		delTcontMsg,
+		ic.InterAdapterMessageType_DELETE_TCONT_REQUEST,
+		f.deviceHandler.device.Type,
+		onuDev.deviceType,
+		onuDev.deviceID,
+		onuDev.proxyDeviceID, ""); sendErr != nil {
+		return olterrors.NewErrCommunication("send-delete-tcont-to-onu-adapter",
+			log.Fields{
+				"from-adapter": f.deviceHandler.device.Type,
+				"to-adapter":   onuDev.deviceType, "onu-id": onuDev.deviceID,
+				"proxyDeviceID": onuDev.proxyDeviceID,
+				"device-id":     f.deviceHandler.device.Id}, sendErr)
+	}
+	logger.Infow(ctx, "success-sending-del-tcont-to-onu-adapter",
+		log.Fields{
+			"msg":       delTcontMsg,
+			"device-id": f.deviceHandler.device.Id})
+	return nil
+}
+
+func (f *OpenOltFlowMgr) deletePendingFlows(ctx context.Context, Intf uint32, onuID int32, uniID int32) {
+	pnFlDelKey := pendingFlowDeleteKey{Intf, uint32(onuID), uint32(uniID)}
+	if val, ok := f.pendingFlowDelete.Load(pnFlDelKey); ok {
+		if val.(int) > 0 {
+			pnFlDels := val.(int) - 1
+			if pnFlDels > 0 {
+				logger.Debugw(ctx, "flow-delete-succeeded--more-pending",
+					log.Fields{
+						"intf":               Intf,
+						"onu-id":             onuID,
+						"uni-id":             uniID,
+						"currpendingflowcnt": pnFlDels,
+						"device-id":          f.deviceHandler.device.Id})
+				f.pendingFlowDelete.Store(pnFlDelKey, pnFlDels)
+			} else {
+				logger.Debugw(ctx, "all-pending-flow-deletes-handled--removing-entry-from-map",
+					log.Fields{
+						"intf":      Intf,
+						"onu-id":    onuID,
+						"uni-id":    uniID,
+						"device-id": f.deviceHandler.device.Id})
+				f.pendingFlowDelete.Delete(pnFlDelKey)
+			}
+		}
+	} else {
+		logger.Debugw(ctx, "no-pending-delete-flows-found",
+			log.Fields{
+				"intf":      Intf,
+				"onu-id":    onuID,
+				"uni-id":    uniID,
+				"device-id": f.deviceHandler.device.Id})
+
+	}
+
+}
+
+// Once the gemport is released for a given onu, it also has to be cleared from local cache
+// which was used for deriving the gemport->logicalPortNo during packet-in.
+// Otherwise stale info continues to exist after gemport is freed and wrong logicalPortNo
+// is conveyed to ONOS during packet-in OF message.
+func (f *OpenOltFlowMgr) deleteGemPortFromLocalCache(ctx context.Context, intfID uint32, onuID uint32, gemPortID uint32) {
+
+	f.onuGemInfoLock.Lock()
+	defer f.onuGemInfoLock.Unlock()
+
+	logger.Infow(ctx, "deleting-gem-from-local-cache",
+		log.Fields{
+			"gem-port-id": gemPortID,
+			"intf-id":     intfID,
+			"onu-id":      onuID,
+			"device-id":   f.deviceHandler.device.Id,
+			"onu-gem":     f.onuGemInfo[intfID]})
+	onugem := f.onuGemInfo[intfID]
+deleteLoop:
+	for i, onu := range onugem {
+		if onu.OnuID == onuID {
+			for j, gem := range onu.GemPorts {
+				// If the gemport is found, delete it from local cache.
+				if gem == gemPortID {
+					onu.GemPorts = append(onu.GemPorts[:j], onu.GemPorts[j+1:]...)
+					onugem[i] = onu
+					logger.Infow(ctx, "removed-gemport-from-local-cache",
+						log.Fields{
+							"intf-id":           intfID,
+							"onu-id":            onuID,
+							"deletedgemport-id": gemPortID,
+							"gemports":          onu.GemPorts,
+							"device-id":         f.deviceHandler.device.Id})
+					break deleteLoop
+				}
+			}
+			break deleteLoop
+		}
+	}
+}
+
+//clearResources clears pon resources in kv store and the device
+// nolint: gocyclo
+func (f *OpenOltFlowMgr) clearResources(ctx context.Context, flow *ofp.OfpFlowStats, Intf uint32, onuID int32, uniID int32,
+	gemPortID int32, flowID uint32, flowDirection string,
+	portNum uint32, updatedFlows []rsrcMgr.FlowInfo) error {
+
+	tpID, err := getTpIDFromFlow(ctx, flow)
+	if err != nil {
+		return olterrors.NewErrNotFound("tp-id",
+			log.Fields{
+				"flow":      flow,
+				"intf":      Intf,
+				"onu-id":    onuID,
+				"uni-id":    uniID,
+				"device-id": f.deviceHandler.device.Id}, err)
+	}
+
+	if len(updatedFlows) >= 0 {
+		// There are still flows referencing the same flow_id.
+		// So the flow should not be freed yet.
+		// For ex: Case of HSIA where same flow is shared
+		// between DS and US.
+		if err := f.updateFlowInfoToKVStore(ctx, int32(Intf), int32(onuID), int32(uniID), flowID, &updatedFlows); err != nil {
+			_ = olterrors.NewErrPersistence("update", "flow", flowID,
+				log.Fields{
+					"flow":      updatedFlows,
+					"device-id": f.deviceHandler.device.Id}, err).Log()
+		}
+		if len(updatedFlows) == 0 {
+			// Do this for subscriber flows only (not trap from NNI flows)
+			if onuID != -1 && uniID != -1 {
+				pnFlDelKey := pendingFlowDeleteKey{Intf, uint32(onuID), uint32(uniID)}
+				if val, ok := f.pendingFlowDelete.Load(pnFlDelKey); !ok {
+					logger.Debugw(ctx, "creating-entry-for-pending-flow-delete",
+						log.Fields{
+							"flow-id":   flowID,
+							"intf":      Intf,
+							"onu-id":    onuID,
+							"uni-id":    uniID,
+							"device-id": f.deviceHandler.device.Id})
+					f.pendingFlowDelete.Store(pnFlDelKey, 1)
+				} else {
+					pnFlDels := val.(int) + 1
+					logger.Debugw(ctx, "updating-flow-delete-entry",
+						log.Fields{
+							"flow-id":            flowID,
+							"intf":               Intf,
+							"onu-id":             onuID,
+							"uni-id":             uniID,
+							"currPendingFlowCnt": pnFlDels,
+							"device-id":          f.deviceHandler.device.Id})
+					f.pendingFlowDelete.Store(pnFlDelKey, pnFlDels)
+				}
+
+				defer f.deletePendingFlows(ctx, Intf, onuID, uniID)
+			}
+
+			logger.Debugw(ctx, "releasing-flow-id-to-resource-manager",
+				log.Fields{
+					"Intf":      Intf,
+					"onu-id":    onuID,
+					"uni-id":    uniID,
+					"flow-id":   flowID,
+					"device-id": f.deviceHandler.device.Id})
+			f.resourceMgr.FreeFlowID(ctx, Intf, int32(onuID), int32(uniID), flowID)
+
+			uni := getUniPortPath(f.deviceHandler.device.Id, Intf, onuID, uniID)
+			tpPath := f.getTPpath(ctx, Intf, uni, tpID)
+			logger.Debugw(ctx, "getting-techprofile-instance-for-subscriber",
+				log.Fields{
+					"TP-PATH":   tpPath,
+					"device-id": f.deviceHandler.device.Id})
+			techprofileInst, err := f.techprofile[Intf].GetTPInstanceFromKVStore(ctx, tpID, tpPath)
+			if err != nil || techprofileInst == nil { // This should not happen, something wrong in KV backend transaction
+				return olterrors.NewErrNotFound("tech-profile-in-kv-store",
+					log.Fields{
+						"tp-id": tpID,
+						"path":  tpPath}, err)
+			}
+
+			gemPK := gemPortKey{Intf, uint32(gemPortID)}
+			used, err := f.isGemPortUsedByAnotherFlow(ctx, gemPK)
+			if err != nil {
+				return err
+			}
+			if used {
+				if f.perGemPortLock.TryLock(gemPK) {
+					flowIDs := f.flowsUsedByGemPort[gemPK]
+					for i, flowIDinMap := range flowIDs {
+						if flowIDinMap == flowID {
+							flowIDs = append(flowIDs[:i], flowIDs[i+1:]...)
+							// everytime flowsUsedByGemPort cache is updated the same should be updated
+							// in kv store by calling UpdateFlowIDsForGem
+							f.flowsUsedByGemPort[gemPK] = flowIDs
+							if err := f.resourceMgr.UpdateFlowIDsForGem(ctx, Intf, uint32(gemPortID), flowIDs); err != nil {
+								return err
+							}
+							break
+						}
+					}
+					logger.Debugw(ctx, "gem-port-id-is-still-used-by-other-flows",
+						log.Fields{
+							"gemport-id":  gemPortID,
+							"usedByFlows": flowIDs,
+							"device-id":   f.deviceHandler.device.Id})
+					f.perGemPortLock.Unlock(gemPK)
+					return nil
+				}
+
+				logger.Error(ctx, "failed-to-acquire-per-gem-port-lock",
+					log.Fields{
+						"gemport-id": gemPortID,
+						"device-id":  f.deviceHandler.device.Id,
+						"key":        gemPK,
+					})
+				return olterrors.NewErrAdapter("failed-to-acquire-per-gem-port-lock", log.Fields{
+					"gemport-id": gemPortID,
+					"device-id":  f.deviceHandler.device.Id,
+					"key":        gemPK,
+				}, nil)
+			}
+			logger.Debugf(ctx, "gem-port-id %d is-not-used-by-another-flow--releasing-the-gem-port", gemPortID)
+			f.resourceMgr.RemoveGemPortIDForOnu(ctx, Intf, uint32(onuID), uint32(uniID), uint32(gemPortID))
+			// TODO: The TrafficQueue corresponding to this gem-port also should be removed immediately.
+			// But it is anyway eventually  removed later when the TechProfile is freed, so not a big issue for now.
+			f.resourceMgr.RemoveGEMportPonportToOnuMapOnKVStore(ctx, uint32(gemPortID), Intf)
+			f.deleteGemPortFromLocalCache(ctx, Intf, uint32(onuID), uint32(gemPortID))
+			f.onuIdsLock.Lock()
+			//everytime an entry is deleted from flowsUsedByGemPort cache, the same should be updated in kv as well
+			// by calling DeleteFlowIDsForGem
+			if f.perGemPortLock.TryLock(gemPK) {
+				delete(f.flowsUsedByGemPort, gemPK)
+				f.perGemPortLock.Unlock(gemPK)
+			} else {
+				logger.Error(ctx, "failed-to-acquire-per-gem-port-lock",
+					log.Fields{
+						"device-id": f.deviceHandler.device.Id,
+						"key":       gemPK,
+					})
+			}
+			f.resourceMgr.DeleteFlowIDsForGem(ctx, Intf, uint32(gemPortID))
+			f.resourceMgr.FreeGemPortID(ctx, Intf, uint32(onuID), uint32(uniID), uint32(gemPortID))
+			f.onuIdsLock.Unlock()
+			// Delete the gem port on the ONU.
+			if err := f.sendDeleteGemPortToChild(ctx, Intf, uint32(onuID), uint32(uniID), uint32(gemPortID), tpPath); err != nil {
+				logger.Errorw(ctx, "error-processing-delete-gem-port-towards-onu",
+					log.Fields{
+						"err":        err,
+						"intf":       Intf,
+						"onu-id":     onuID,
+						"uni-id":     uniID,
+						"device-id":  f.deviceHandler.device.Id,
+						"gemport-id": gemPortID})
+			}
+			switch techprofileInst := techprofileInst.(type) {
+			case *tp.TechProfile:
+				ok, _ := f.isTechProfileUsedByAnotherGem(ctx, Intf, uint32(onuID), uint32(uniID), tpID, techprofileInst, uint32(gemPortID))
+				if !ok {
+					if err := f.resourceMgr.RemoveTechProfileIDForOnu(ctx, Intf, uint32(onuID), uint32(uniID), tpID); err != nil {
+						logger.Warn(ctx, err)
+					}
+					if err := f.DeleteTechProfileInstance(ctx, Intf, uint32(onuID), uint32(uniID), "", tpID); err != nil {
+						logger.Warn(ctx, err)
+					}
+					if err := f.RemoveSchedulerQueues(ctx, schedQueue{direction: tp_pb.Direction_UPSTREAM, intfID: Intf, onuID: uint32(onuID), uniID: uint32(uniID), tpID: tpID, uniPort: portNum, tpInst: techprofileInst}); err != nil {
+						logger.Warn(ctx, err)
+					}
+					if err := f.RemoveSchedulerQueues(ctx, schedQueue{direction: tp_pb.Direction_DOWNSTREAM, intfID: Intf, onuID: uint32(onuID), uniID: uint32(uniID), tpID: tpID, uniPort: portNum, tpInst: techprofileInst}); err != nil {
+						logger.Warn(ctx, err)
+					}
+					f.resourceMgr.FreeAllocID(ctx, Intf, uint32(onuID), uint32(uniID), techprofileInst.UsScheduler.AllocID)
+					// Delete the TCONT on the ONU.
+					if err := f.sendDeleteTcontToChild(ctx, Intf, uint32(onuID), uint32(uniID), uint32(techprofileInst.UsScheduler.AllocID), tpPath); err != nil {
+						logger.Errorw(ctx, "error-processing-delete-tcont-towards-onu",
+							log.Fields{
+								"intf":      Intf,
+								"onu-id":    onuID,
+								"uni-id":    uniID,
+								"device-id": f.deviceHandler.device.Id,
+								"alloc-id":  techprofileInst.UsScheduler.AllocID})
+					}
+				}
+			case *tp.EponProfile:
+				if err := f.resourceMgr.RemoveTechProfileIDForOnu(ctx, Intf, uint32(onuID), uint32(uniID), tpID); err != nil {
+					logger.Warn(ctx, err)
+				}
+				if err := f.DeleteTechProfileInstance(ctx, Intf, uint32(onuID), uint32(uniID), "", tpID); err != nil {
+					logger.Warn(ctx, err)
+				}
+				f.resourceMgr.FreeAllocID(ctx, Intf, uint32(onuID), uint32(uniID), techprofileInst.AllocID)
+				// Delete the TCONT on the ONU.
+				if err := f.sendDeleteTcontToChild(ctx, Intf, uint32(onuID), uint32(uniID), uint32(techprofileInst.AllocID), tpPath); err != nil {
+					logger.Errorw(ctx, "error-processing-delete-tcont-towards-onu",
+						log.Fields{
+							"intf":      Intf,
+							"onu-id":    onuID,
+							"uni-id":    uniID,
+							"device-id": f.deviceHandler.device.Id,
+							"alloc-id":  techprofileInst.AllocID})
+				}
+			default:
+				logger.Errorw(ctx, "error-unknown-tech",
+					log.Fields{
+						"techprofileInst": techprofileInst})
+			}
+		}
+	}
+	return nil
+}
+
+// nolint: gocyclo
+func (f *OpenOltFlowMgr) clearFlowFromResourceManager(ctx context.Context, flow *ofp.OfpFlowStats, flowDirection string) {
+
+	logger.Infow(ctx, "clear-flow-from-resource-manager",
+		log.Fields{
+			"flowDirection": flowDirection,
+			"flow":          *flow,
+			"device-id":     f.deviceHandler.device.Id})
+
+	if flowDirection == Multicast {
+		f.clearMulticastFlowFromResourceManager(ctx, flow)
+		return
+	}
+
+	classifierInfo := make(map[string]interface{})
+
+	portNum, Intf, onu, uni, inPort, ethType, err := FlowExtractInfo(ctx, flow, flowDirection)
+	if err != nil {
+		logger.Error(ctx, err)
+		return
+	}
+
+	onuID := int32(onu)
+	uniID := int32(uni)
+
+	for _, field := range flows.GetOfbFields(flow) {
+		if field.Type == flows.IP_PROTO {
+			classifierInfo[IPProto] = field.GetIpProto()
+			logger.Debugw(ctx, "field-type-ip-proto", log.Fields{"classifierInfo[IP_PROTO]": classifierInfo[IPProto].(uint32)})
+		}
+	}
+	logger.Infow(ctx, "extracted-access-info-from-flow-to-be-deleted",
+		log.Fields{
+			"flow-id": flow.Id,
+			"intf-id": Intf,
+			"onu-id":  onuID,
+			"uni-id":  uniID})
+
+	if ethType == LldpEthType || ((classifierInfo[IPProto] == IPProtoDhcp) && (flowDirection == "downstream")) {
+		onuID = -1
+		uniID = -1
+		logger.Debug(ctx, "trap-on-nni-flow-set-oni--uni-to- -1")
+		Intf, err = IntfIDFromNniPortNum(ctx, inPort)
+		if err != nil {
+			logger.Errorw(ctx, "invalid-in-port-number",
+				log.Fields{
+					"port-number": inPort,
+					"error":       err})
+			return
+		}
+	}
+	flowIds := f.resourceMgr.GetCurrentFlowIDsForOnu(ctx, Intf, onuID, uniID)
+	for _, flowID := range flowIds {
+		flowInfo := f.resourceMgr.GetFlowIDInfo(ctx, Intf, onuID, uniID, flowID)
+		if flowInfo == nil {
+			logger.Debugw(ctx, "no-flowinfo-found-in-kv-store",
+				log.Fields{
+					"intf":    Intf,
+					"onu-id":  onuID,
+					"uni-id":  uniID,
+					"flow-id": flowID})
+			return
+		}
+
+		updatedFlows := *flowInfo
+		for i, storedFlow := range updatedFlows {
+			if flow.Id == storedFlow.LogicalFlowID {
+				removeFlowMessage := openoltpb2.Flow{FlowId: storedFlow.Flow.FlowId, FlowType: storedFlow.Flow.FlowType}
+				logger.Debugw(ctx, "flow-to-be-deleted", log.Fields{"flow": storedFlow})
+				// DKB
+				if err = f.removeFlowFromDevice(ctx, &removeFlowMessage, flow.Id); err != nil {
+					logger.Errorw(ctx, "failed-to-remove-flow", log.Fields{"error": err})
+					return
+				}
+				logger.Info(ctx, "flow-removed-from-device-successfully", log.Fields{
+					"flow-id":        flow.Id,
+					"stored-flow":    storedFlow,
+					"device-id":      f.deviceHandler.device.Id,
+					"stored-flow-id": flowID,
+					"onu-id":         onuID,
+					"intf":           Intf,
+				})
+				//Remove the Flow from FlowInfo
+				updatedFlows = append(updatedFlows[:i], updatedFlows[i+1:]...)
+				if err = f.clearResources(ctx, flow, Intf, onuID, uniID, storedFlow.Flow.GemportId,
+					flowID, flowDirection, portNum, updatedFlows); err != nil {
+					logger.Error(ctx, "failed-to-clear-resources-for-flow", log.Fields{
+						"flow-id":        flow.Id,
+						"stored-flow":    storedFlow,
+						"device-id":      f.deviceHandler.device.Id,
+						"stored-flow-id": flowID,
+						"onu-id":         onuID,
+						"intf":           Intf,
+					})
+					return
+				}
+			}
+		}
+	}
+}
+
+//clearMulticastFlowFromResourceManager  removes a multicast flow from the KV store and
+// clears resources reserved for this multicast flow
+func (f *OpenOltFlowMgr) clearMulticastFlowFromResourceManager(ctx context.Context, flow *ofp.OfpFlowStats) {
+	classifierInfo := make(map[string]interface{})
+	formulateClassifierInfoFromFlow(ctx, classifierInfo, flow)
+	networkInterfaceID, err := f.getNNIInterfaceIDOfMulticastFlow(ctx, classifierInfo)
+
+	if err != nil {
+		logger.Warnw(ctx, "no-inport-found--cannot-release-resources-of-the-multicast-flow", log.Fields{"flowId:": flow.Id})
+		return
+	}
+
+	var onuID = int32(NoneOnuID)
+	var uniID = int32(NoneUniID)
+	var flowID uint32
+
+	flowIds := f.resourceMgr.GetCurrentFlowIDsForOnu(ctx, networkInterfaceID, onuID, uniID)
+
+	for _, flowID = range flowIds {
+		flowInfo := f.resourceMgr.GetFlowIDInfo(ctx, networkInterfaceID, onuID, uniID, flowID)
+		if flowInfo == nil {
+			logger.Debugw(ctx, "no-multicast-flowinfo-found-in-the-kv-store",
+				log.Fields{
+					"intf":    networkInterfaceID,
+					"onu-id":  onuID,
+					"uni-id":  uniID,
+					"flow-id": flowID})
+			continue
+		}
+		updatedFlows := *flowInfo
+		for i, storedFlow := range updatedFlows {
+			if flow.Id == storedFlow.LogicalFlowID {
+				removeFlowMessage := openoltpb2.Flow{FlowId: storedFlow.Flow.FlowId, FlowType: storedFlow.Flow.FlowType}
+				logger.Debugw(ctx, "multicast-flow-to-be-deleted",
+					log.Fields{
+						"flow":      storedFlow,
+						"flow-id":   flow.Id,
+						"device-id": f.deviceHandler.device.Id})
+				//remove from device
+				if err := f.removeFlowFromDevice(ctx, &removeFlowMessage, flow.Id); err != nil {
+					// DKB
+					logger.Errorw(ctx, "failed-to-remove-multicast-flow",
+						log.Fields{
+							"flow-id": flow.Id,
+							"error":   err})
+					return
+				}
+				logger.Infow(ctx, "multicast-flow-removed-from-device-successfully", log.Fields{"flow-id": flow.Id})
+				//Remove the Flow from FlowInfo
+				updatedFlows = append(updatedFlows[:i], updatedFlows[i+1:]...)
+				if err := f.updateFlowInfoToKVStore(ctx, int32(networkInterfaceID), NoneOnuID, NoneUniID, flowID, &updatedFlows); err != nil {
+					logger.Errorw(ctx, "failed-to-delete-multicast-flow-from-the-kv-store",
+						log.Fields{"flow": storedFlow,
+							"err": err})
+					return
+				}
+				//release flow id
+				logger.Debugw(ctx, "releasing-multicast-flow-id",
+					log.Fields{"flow-id": flowID,
+						"interfaceID": networkInterfaceID})
+				f.resourceMgr.FreeFlowID(ctx, uint32(networkInterfaceID), NoneOnuID, NoneUniID, flowID)
+			}
+		}
+	}
+}
+
+//RemoveFlow removes the flow from the device
+func (f *OpenOltFlowMgr) RemoveFlow(ctx context.Context, flow *ofp.OfpFlowStats) error {
+	logger.Infow(ctx, "removing-flow", log.Fields{"flow": *flow})
+	var direction string
+	actionInfo := make(map[string]interface{})
+
+	for _, action := range flows.GetActions(flow) {
+		if action.Type == flows.OUTPUT {
+			if out := action.GetOutput(); out != nil {
+				actionInfo[Output] = out.GetPort()
+				logger.Debugw(ctx, "action-type-output", log.Fields{"out_port": actionInfo[Output].(uint32)})
+			} else {
+				logger.Error(ctx, "invalid-output-port-in-action")
+				return olterrors.NewErrInvalidValue(log.Fields{"invalid-out-port-action": 0}, nil)
+			}
+		}
+	}
+
+	if flows.HasGroup(flow) {
+		direction = Multicast
+		f.clearFlowFromResourceManager(ctx, flow, direction)
+		return nil
+	} else if IsUpstream(actionInfo[Output].(uint32)) {
+		direction = Upstream
+	} else {
+		direction = Downstream
+	}
+
+	_, intfID, onuID, uniID, _, _, err := FlowExtractInfo(ctx, flow, direction)
+	if err != nil {
+		return err
+	}
+
+	userKey := tpLockKey{intfID, onuID, uniID}
+
+	if f.perUserFlowHandleLock.TryLock(userKey) {
+		f.clearFlowFromResourceManager(ctx, flow, direction) //TODO: Take care of the limitations
+		f.perUserFlowHandleLock.Unlock(userKey)
+	} else {
+		// Ideally this should never happen
+		logger.Errorw(ctx, "failed-to-acquire-lock-to-remove-flow--remove-aborted", log.Fields{"flow": flow})
+		return errors.New("failed-to-acquire-per-user-lock")
+	}
+
+	return nil
+}
+
+func (f *OpenOltFlowMgr) waitForFlowDeletesToCompleteForOnu(ctx context.Context, intfID uint32, onuID uint32,
+	uniID uint32, ch chan bool) {
+	pnFlDelKey := pendingFlowDeleteKey{intfID, onuID, uniID}
+	for {
+		select {
+		case <-time.After(20 * time.Millisecond):
+			if flowDelRefCnt, ok := f.pendingFlowDelete.Load(pnFlDelKey); !ok || flowDelRefCnt == 0 {
+				logger.Debug(ctx, "pending-flow-deletes-completed")
+				ch <- true
+				return
+			}
+		case <-ctx.Done():
+			logger.Error(ctx, "flow-delete-wait-handler-routine-canceled")
+			return
+		}
+	}
+}
+
+//isIgmpTrapDownstreamFlow return true if the flow is a downsteam IGMP trap-to-host flow; false otherwise
+func isIgmpTrapDownstreamFlow(classifierInfo map[string]interface{}) bool {
+	if portType := IntfIDToPortTypeName(classifierInfo[InPort].(uint32)); portType == voltha.Port_ETHERNET_NNI {
+		if ethType, ok := classifierInfo[EthType]; ok {
+			if ethType.(uint32) == IPv4EthType {
+				if ipProto, ok := classifierInfo[IPProto]; ok {
+					if ipProto.(uint32) == IgmpProto {
+						return true
+					}
+				}
+			}
+		}
+	}
+	return false
+}
+
+// AddFlow add flow to device
+// nolint: gocyclo
+func (f *OpenOltFlowMgr) AddFlow(ctx context.Context, flow *ofp.OfpFlowStats, flowMetadata *voltha.FlowMetadata) error {
+	classifierInfo := make(map[string]interface{})
+	actionInfo := make(map[string]interface{})
+	var UsMeterID uint32
+	var DsMeterID uint32
+
+	logger.Infow(ctx, "adding-flow",
+		log.Fields{
+			"flow":         flow,
+			"flowmetadata": flowMetadata})
+	formulateClassifierInfoFromFlow(ctx, classifierInfo, flow)
+
+	err := formulateActionInfoFromFlow(ctx, actionInfo, classifierInfo, flow)
+	if err != nil {
+		// Error logging is already done in the called function
+		// So just return in case of error
+		return err
+	}
+
+	if flows.HasGroup(flow) {
+		// handle multicast flow
+		return f.handleFlowWithGroup(ctx, actionInfo, classifierInfo, flow)
+	}
+
+	/* Controller bound trap flows */
+	err = formulateControllerBoundTrapFlowInfo(ctx, actionInfo, classifierInfo, flow)
+	if err != nil {
+		// error if any, already logged in the called function
+		return err
+	}
+
+	logger.Debugw(ctx, "flow-ports",
+		log.Fields{
+			"classifierinfo_inport": classifierInfo[InPort],
+			"action_output":         actionInfo[Output]})
+	portNo, intfID, onuID, uniID := ExtractAccessFromFlow(classifierInfo[InPort].(uint32), actionInfo[Output].(uint32))
+
+	if ethType, ok := classifierInfo[EthType]; ok {
+		if ethType.(uint32) == LldpEthType {
+			logger.Info(ctx, "adding-lldp-flow")
+			return f.addLLDPFlow(ctx, flow, portNo)
+		}
+	}
+	if ipProto, ok := classifierInfo[IPProto]; ok {
+		if ipProto.(uint32) == IPProtoDhcp {
+			if udpSrc, ok := classifierInfo[UDPSrc]; ok {
+				if udpSrc.(uint32) == uint32(67) || udpSrc.(uint32) == uint32(546) {
+					logger.Debug(ctx, "trap-dhcp-from-nni-flow")
+					return f.addDHCPTrapFlowOnNNI(ctx, flow, classifierInfo, portNo)
+				}
+			}
+		}
+	}
+	if isIgmpTrapDownstreamFlow(classifierInfo) {
+		logger.Debug(ctx, "trap-igmp-from-nni-flow")
+		return f.addIgmpTrapFlowOnNNI(ctx, flow, classifierInfo, portNo)
+	}
+
+	f.resourceMgr.AddUniPortToOnuInfo(ctx, intfID, onuID, portNo)
+
+	TpID, err := getTpIDFromFlow(ctx, flow)
+	if err != nil {
+		return olterrors.NewErrNotFound("tpid-for-flow",
+			log.Fields{
+				"flow":    flow,
+				"intf-id": IntfID,
+				"onu-id":  onuID,
+				"uni-id":  uniID}, err)
+	}
+	logger.Debugw(ctx, "tpid-for-this-subcriber",
+		log.Fields{
+			"tp-id":   TpID,
+			"intf-id": intfID,
+			"onu-id":  onuID,
+			"uni-id":  uniID})
+	if IsUpstream(actionInfo[Output].(uint32)) {
+		UsMeterID = flows.GetMeterIdFromFlow(flow)
+		logger.Debugw(ctx, "upstream-flow-meter-id", log.Fields{"us-meter-id": UsMeterID})
+	} else {
+		DsMeterID = flows.GetMeterIdFromFlow(flow)
+		logger.Debugw(ctx, "downstream-flow-meter-id", log.Fields{"ds-meter-id": DsMeterID})
+
+	}
+
+	pnFlDelKey := pendingFlowDeleteKey{intfID, onuID, uniID}
+	if _, ok := f.pendingFlowDelete.Load(pnFlDelKey); !ok {
+		logger.Debugw(ctx, "no-pending-flows-found--going-ahead-with-flow-install",
+			log.Fields{
+				"intf-id": intfID,
+				"onu-id":  onuID,
+				"uni-id":  uniID})
+		f.divideAndAddFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, uint32(TpID), UsMeterID, DsMeterID, flowMetadata)
+	} else {
+		pendingFlowDelComplete := make(chan bool)
+		go f.waitForFlowDeletesToCompleteForOnu(ctx, intfID, onuID, uniID, pendingFlowDelComplete)
+		select {
+		case <-pendingFlowDelComplete:
+			logger.Debugw(ctx, "all-pending-flow-deletes-completed",
+				log.Fields{
+					"intf-id": intfID,
+					"onu-id":  onuID,
+					"uni-id":  uniID})
+			f.divideAndAddFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, uint32(TpID), UsMeterID, DsMeterID, flowMetadata)
+
+		case <-time.After(10 * time.Second):
+			return olterrors.NewErrTimeout("pending-flow-deletes",
+				log.Fields{
+					"intf-id": intfID,
+					"onu-id":  onuID,
+					"uni-id":  uniID}, nil)
+		}
+	}
+
+	logger.Debugw(ctx, "end-adding-flow",
+		log.Fields{
+			"flow":         flow,
+			"flowmetadata": flowMetadata})
+
+	return nil
+}
+
+// handleFlowWithGroup adds multicast flow to the device.
+func (f *OpenOltFlowMgr) handleFlowWithGroup(ctx context.Context, actionInfo, classifierInfo map[string]interface{}, flow *ofp.OfpFlowStats) error {
+	classifierInfo[PacketTagType] = DoubleTag
+	logger.Debugw(ctx, "add-multicast-flow", log.Fields{
+		"classifier-info": classifierInfo,
+		"actionInfo":      actionInfo})
+
+	networkInterfaceID, err := f.getNNIInterfaceIDOfMulticastFlow(ctx, classifierInfo)
+	if err != nil {
+		return olterrors.NewErrNotFound("multicast-in-port", log.Fields{"classifier": classifierInfo}, err)
+	}
+	mcastFlowClassificationByEthDst := false
+
+	if mcastFlowClassificationByEthDst {
+		//replace ipDst with ethDst
+		if ipv4Dst, ok := classifierInfo[Ipv4Dst]; ok &&
+			flows.IsMulticastIp(ipv4Dst.(uint32)) {
+			// replace ipv4_dst classifier with eth_dst
+			multicastMac := flows.ConvertToMulticastMacBytes(ipv4Dst.(uint32))
+			delete(classifierInfo, Ipv4Dst)
+			classifierInfo[EthDst] = multicastMac
+			logger.Debugw(ctx, "multicast-ip-to-mac-conversion-success",
+				log.Fields{
+					"ip:":  ipv4Dst.(uint32),
+					"mac:": multicastMac})
+		}
+	}
+	delete(classifierInfo, EthType)
+
+	onuID := NoneOnuID
+	uniID := NoneUniID
+	gemPortID := NoneGemPortID
+
+	flowStoreCookie := getFlowStoreCookie(ctx, classifierInfo, uint32(0))
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Infow(ctx, "multicast-flow-exists-not-re-adding", log.Fields{"classifier-info": classifierInfo})
+		return nil
+	}
+	flowID, err := f.resourceMgr.GetFlowID(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), uint32(gemPortID), flowStoreCookie, "", 0, 0)
+	if err != nil {
+		return olterrors.NewErrNotFound("multicast-flow-id",
+			log.Fields{
+				"interface-id": networkInterfaceID,
+				"onu-id":       onuID,
+				"uni-id":       uniID,
+				"gem-port-id":  gemPortID,
+				"cookie":       flowStoreCookie},
+			err)
+	}
+	classifierProto, err := makeOpenOltClassifierField(classifierInfo)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifierInfo}, err)
+	}
+	groupID := actionInfo[GroupID].(uint32)
+	multicastFlow := openoltpb2.Flow{
+		FlowId:        flowID,
+		FlowType:      Multicast,
+		NetworkIntfId: int32(networkInterfaceID),
+		GroupId:       groupID,
+		Classifier:    classifierProto,
+		Priority:      int32(flow.Priority),
+		Cookie:        flow.Cookie}
+
+	if err := f.addFlowToDevice(ctx, flow, &multicastFlow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, log.Fields{"flow": multicastFlow}, err)
+	}
+	logger.Info(ctx, "multicast-flow-added-to-device-successfully")
+	if group, _, err := f.GetFlowGroupFromKVStore(ctx, groupID, true); err == nil {
+		//calling groupAdd to set group members after multicast flow creation
+		if err := f.ModifyGroup(ctx, group); err != nil {
+			return olterrors.NewErrGroupOp("modify", groupID, log.Fields{"group": group}, err)
+		}
+		//cached group can be removed now
+		if err := f.resourceMgr.RemoveFlowGroupFromKVStore(ctx, groupID, true); err != nil {
+			logger.Warnw(ctx, "failed-to-remove-flow-group", log.Fields{"group-id": groupID, "error": err})
+		}
+	}
+
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &multicastFlow, flowStoreCookie, MulticastFlow, flowID, flow.Id)
+	if err = f.updateFlowInfoToKVStore(ctx, int32(networkInterfaceID),
+		int32(onuID),
+		int32(uniID),
+		flowID, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flowID, log.Fields{"flow": multicastFlow}, err)
+	}
+	return nil
+}
+
+//getNNIInterfaceIDOfMulticastFlow returns associated NNI interface id of the inPort criterion if exists; returns the first NNI interface of the device otherwise
+func (f *OpenOltFlowMgr) getNNIInterfaceIDOfMulticastFlow(ctx context.Context, classifierInfo map[string]interface{}) (uint32, error) {
+	if inPort, ok := classifierInfo[InPort]; ok {
+		nniInterfaceID, err := IntfIDFromNniPortNum(ctx, inPort.(uint32))
+		if err != nil {
+			return 0, olterrors.NewErrInvalidValue(log.Fields{"nni-in-port-number": inPort}, err)
+		}
+		return nniInterfaceID, nil
+	}
+	nniPorts, e := f.resourceMgr.GetNNIFromKVStore(ctx)
+	if e == nil && len(nniPorts) > 0 {
+		return nniPorts[0], nil
+	}
+	return 0, olterrors.NewErrNotFound("nni-port", nil, e).Log()
+}
+
+// AddGroup add or update the group
+func (f *OpenOltFlowMgr) AddGroup(ctx context.Context, group *ofp.OfpGroupEntry) error {
+	logger.Infow(ctx, "add-group", log.Fields{"group": group})
+	if group == nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"group": group}, nil)
+	}
+
+	groupToOlt := openoltpb2.Group{
+		GroupId: group.Desc.GroupId,
+		Command: openoltpb2.Group_SET_MEMBERS,
+		Action:  f.buildGroupAction(),
+	}
+
+	logger.Debugw(ctx, "sending-group-to-device", log.Fields{"groupToOlt": groupToOlt})
+	_, err := f.deviceHandler.Client.PerformGroupOperation(ctx, &groupToOlt)
+	if err != nil {
+		return olterrors.NewErrAdapter("add-group-operation-failed", log.Fields{"groupToOlt": groupToOlt}, err)
+	}
+	if err := f.resourceMgr.AddFlowGroupToKVStore(ctx, group, true); err != nil {
+		return olterrors.NewErrPersistence("add", "flow-group", group.Desc.GroupId, log.Fields{"group": group}, err)
+	}
+	logger.Infow(ctx, "add-group-operation-performed-on-the-device-successfully ", log.Fields{"groupToOlt": groupToOlt})
+	return nil
+}
+
+// DeleteGroup deletes a group from the device
+func (f *OpenOltFlowMgr) DeleteGroup(ctx context.Context, group *ofp.OfpGroupEntry) error {
+	logger.Debugw(ctx, "delete-group", log.Fields{"group": group})
+	if group == nil {
+		logger.Error(ctx, "unable-to-delete-group--invalid-argument--group-is-nil")
+		return olterrors.NewErrInvalidValue(log.Fields{"group": group}, nil)
+	}
+
+	groupToOlt := openoltpb2.Group{
+		GroupId: group.Desc.GroupId,
+	}
+
+	logger.Debugw(ctx, "deleting-group-from-device", log.Fields{"groupToOlt": groupToOlt})
+	_, err := f.deviceHandler.Client.DeleteGroup(ctx, &groupToOlt)
+	if err != nil {
+		logger.Errorw(ctx, "delete-group-failed-on-dev", log.Fields{"groupToOlt": groupToOlt, "err": err})
+		return olterrors.NewErrAdapter("delete-group-operation-failed", log.Fields{"groupToOlt": groupToOlt}, err)
+	}
+	if err := f.resourceMgr.RemoveFlowGroupFromKVStore(ctx, group.Desc.GroupId, false); err != nil {
+		return olterrors.NewErrPersistence("delete", "flow-group", group.Desc.GroupId, log.Fields{"group": group}, err)
+	}
+	logger.Debugw(ctx, "delete-group-operation-performed-on-the-device-successfully ", log.Fields{"groupToOlt": groupToOlt})
+	return nil
+}
+
+//buildGroupAction creates and returns a group action
+func (f *OpenOltFlowMgr) buildGroupAction() *openoltpb2.Action {
+	var actionCmd openoltpb2.ActionCmd
+	var action openoltpb2.Action
+	action.Cmd = &actionCmd
+	action.Cmd.RemoveOuterTag = true
+	return &action
+}
+
+// ModifyGroup updates the group
+func (f *OpenOltFlowMgr) ModifyGroup(ctx context.Context, group *ofp.OfpGroupEntry) error {
+	logger.Infow(ctx, "modify-group", log.Fields{"group": group})
+	if group == nil || group.Desc == nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"group": group}, nil)
+	}
+
+	newGroup := f.buildGroup(ctx, group.Desc.GroupId, group.Desc.Buckets)
+	val, groupExists, err := f.GetFlowGroupFromKVStore(ctx, group.Desc.GroupId, false)
+
+	if err != nil {
+		return olterrors.NewErrNotFound("flow-group-in-kv-store", log.Fields{"groupId": group.Desc.GroupId}, err)
+	}
+
+	var current *openoltpb2.Group // represents the group on the device
+	if groupExists {
+		// group already exists
+		current = f.buildGroup(ctx, group.Desc.GroupId, val.Desc.GetBuckets())
+		logger.Debugw(ctx, "modify-group--group exists",
+			log.Fields{
+				"group on the device": val,
+				"new":                 group})
+	} else {
+		current = f.buildGroup(ctx, group.Desc.GroupId, nil)
+	}
+
+	logger.Debugw(ctx, "modify-group--comparing-current-and-new",
+		log.Fields{
+			"group on the device": current,
+			"new":                 newGroup})
+	membersToBeAdded := f.findDiff(current, newGroup)
+	membersToBeRemoved := f.findDiff(newGroup, current)
+
+	logger.Infow(ctx, "modify-group--differences found", log.Fields{
+		"membersToBeAdded":   membersToBeAdded,
+		"membersToBeRemoved": membersToBeRemoved,
+		"groupId":            group.Desc.GroupId})
+
+	groupToOlt := openoltpb2.Group{
+		GroupId: group.Desc.GroupId,
+	}
+	var errAdd, errRemoved error
+	if len(membersToBeAdded) > 0 {
+		groupToOlt.Command = openoltpb2.Group_ADD_MEMBERS
+		groupToOlt.Members = membersToBeAdded
+		//execute addMembers
+		errAdd = f.callGroupAddRemove(ctx, &groupToOlt)
+	}
+	if len(membersToBeRemoved) > 0 {
+		groupToOlt.Command = openoltpb2.Group_REMOVE_MEMBERS
+		groupToOlt.Members = membersToBeRemoved
+		//execute removeMembers
+		errRemoved = f.callGroupAddRemove(ctx, &groupToOlt)
+	}
+
+	if errAdd == nil && errRemoved == nil {
+		if err := f.resourceMgr.AddFlowGroupToKVStore(ctx, group, false); err != nil {
+			return olterrors.NewErrPersistence("add", "flow-group", group.Desc.GroupId, log.Fields{"group": group}, err)
+		}
+		logger.Infow(ctx, "modify-group-was-success--storing-group",
+			log.Fields{
+				"group":         group,
+				"existingGroup": current})
+	} else {
+		logger.Warnw(ctx, "one-of-the-group-add/remove-operations-failed--cannot-save-group-modifications",
+			log.Fields{"group": group})
+		if errAdd != nil {
+			return errAdd
+		}
+		return errRemoved
+	}
+	return nil
+}
+
+//callGroupAddRemove performs add/remove buckets operation for the indicated group
+func (f *OpenOltFlowMgr) callGroupAddRemove(ctx context.Context, group *openoltpb2.Group) error {
+	if err := f.performGroupOperation(ctx, group); err != nil {
+		st, _ := status.FromError(err)
+		//ignore already exists error code
+		if st.Code() != codes.AlreadyExists {
+			return olterrors.NewErrGroupOp("groupAddRemove", group.GroupId, log.Fields{"status": st}, err)
+		}
+	}
+	return nil
+}
+
+//findDiff compares group members and finds members which only exists in groups2
+func (f *OpenOltFlowMgr) findDiff(group1 *openoltpb2.Group, group2 *openoltpb2.Group) []*openoltpb2.GroupMember {
+	var members []*openoltpb2.GroupMember
+	for _, bucket := range group2.Members {
+		if !f.contains(group1.Members, bucket) {
+			// bucket does not exist and must be added
+			members = append(members, bucket)
+		}
+	}
+	return members
+}
+
+//contains returns true if the members list contains the given member; false otherwise
+func (f *OpenOltFlowMgr) contains(members []*openoltpb2.GroupMember, member *openoltpb2.GroupMember) bool {
+	for _, groupMember := range members {
+		if groupMember.InterfaceId == member.InterfaceId {
+			return true
+		}
+	}
+	return false
+}
+
+//performGroupOperation call performGroupOperation operation of openolt proto
+func (f *OpenOltFlowMgr) performGroupOperation(ctx context.Context, group *openoltpb2.Group) error {
+	logger.Debugw(ctx, "sending-group-to-device",
+		log.Fields{
+			"groupToOlt": group,
+			"command":    group.Command})
+	_, err := f.deviceHandler.Client.PerformGroupOperation(log.WithSpanFromContext(context.Background(), ctx), group)
+	if err != nil {
+		return olterrors.NewErrAdapter("group-operation-failed", log.Fields{"groupToOlt": group}, err)
+	}
+	return nil
+}
+
+//buildGroup build openoltpb2.Group from given group id and bucket list
+func (f *OpenOltFlowMgr) buildGroup(ctx context.Context, groupID uint32, buckets []*ofp.OfpBucket) *openoltpb2.Group {
+	group := openoltpb2.Group{
+		GroupId: groupID}
+	for _, ofBucket := range buckets {
+		member := f.buildMember(ctx, ofBucket)
+		if member != nil && !f.contains(group.Members, member) {
+			group.Members = append(group.Members, member)
+		}
+	}
+	return &group
+}
+
+//buildMember builds openoltpb2.GroupMember from an OpenFlow bucket
+func (f *OpenOltFlowMgr) buildMember(ctx context.Context, ofBucket *ofp.OfpBucket) *openoltpb2.GroupMember {
+	var outPort uint32
+	outPortFound := false
+	for _, ofAction := range ofBucket.Actions {
+		if ofAction.Type == ofp.OfpActionType_OFPAT_OUTPUT {
+			outPort = ofAction.GetOutput().Port
+			outPortFound = true
+		}
+	}
+
+	if !outPortFound {
+		logger.Debugw(ctx, "bucket-skipped-since-no-out-port-found-in-it", log.Fields{"ofBucket": ofBucket})
+		return nil
+	}
+	interfaceID := IntfIDFromUniPortNum(outPort)
+	logger.Debugw(ctx, "got-associated-interface-id-of-the-port",
+		log.Fields{
+			"portNumber:":  outPort,
+			"interfaceId:": interfaceID})
+	if groupInfo, ok := f.interfaceToMcastQueueMap[interfaceID]; ok {
+		member := openoltpb2.GroupMember{
+			InterfaceId:   interfaceID,
+			InterfaceType: openoltpb2.GroupMember_PON,
+			GemPortId:     groupInfo.gemPortID,
+			Priority:      groupInfo.servicePriority,
+		}
+		//add member to the group
+		return &member
+	}
+	logger.Warnf(ctx, "bucket-skipped-since-interface-2-gem-mapping-cannot-be-found", log.Fields{"ofBucket": ofBucket})
+	return nil
+}
+
+//sendTPDownloadMsgToChild send payload
+func (f *OpenOltFlowMgr) sendTPDownloadMsgToChild(ctx context.Context, intfID uint32, onuID uint32, uniID uint32, uni string, TpID uint32) error {
+
+	onuDev, err := f.getOnuDevice(ctx, intfID, onuID)
+	if err != nil {
+		logger.Errorw(ctx, "couldnt-find-onu-child-device",
+			log.Fields{
+				"intf-id": intfID,
+				"onu-id":  onuID,
+				"uni-id":  uniID})
+		return err
+	}
+	logger.Debugw(ctx, "got-child-device-from-olt-device-handler", log.Fields{"onu-id": onuDev.deviceID})
+
+	tpPath := f.getTPpath(ctx, intfID, uni, TpID)
+	tpDownloadMsg := &ic.InterAdapterTechProfileDownloadMessage{UniId: uniID, Path: tpPath}
+	logger.Debugw(ctx, "sending-load-tech-profile-request-to-brcm-onu-adapter", log.Fields{"tpDownloadMsg": *tpDownloadMsg})
+	sendErr := f.deviceHandler.AdapterProxy.SendInterAdapterMessage(log.WithSpanFromContext(context.Background(), ctx),
+		tpDownloadMsg,
+		ic.InterAdapterMessageType_TECH_PROFILE_DOWNLOAD_REQUEST,
+		f.deviceHandler.device.Type,
+		onuDev.deviceType,
+		onuDev.deviceID,
+		onuDev.proxyDeviceID, "")
+	if sendErr != nil {
+		return olterrors.NewErrCommunication("send-techprofile-download-request",
+			log.Fields{
+				"from-adapter":  f.deviceHandler.device.Type,
+				"to-adapter":    onuDev.deviceType,
+				"onu-id":        onuDev.deviceID,
+				"proxyDeviceID": onuDev.proxyDeviceID}, sendErr)
+	}
+	logger.Infow(ctx, "success-sending-load-tech-profile-request-to-brcm-onu-adapter", log.Fields{"tpDownloadMsg": *tpDownloadMsg})
+	return nil
+}
+
+//UpdateOnuInfo function adds onu info to cache and kvstore
+func (f *OpenOltFlowMgr) UpdateOnuInfo(ctx context.Context, intfID uint32, onuID uint32, serialNum string) error {
+
+	f.onuGemInfoLock.Lock()
+	defer f.onuGemInfoLock.Unlock()
+
+	onu := rsrcMgr.OnuGemInfo{OnuID: onuID, SerialNumber: serialNum, IntfID: intfID}
+	f.onuGemInfo[intfID] = append(f.onuGemInfo[intfID], onu)
+	if err := f.resourceMgr.AddOnuGemInfo(ctx, intfID, onu); err != nil {
+		return err
+	}
+	logger.Infow(ctx, "updated-onuinfo",
+		log.Fields{
+			"intf-id":    intfID,
+			"onu-id":     onuID,
+			"serial-num": serialNum,
+			"onu":        onu,
+			"device-id":  f.deviceHandler.device.Id})
+	return nil
+}
+
+//addGemPortToOnuInfoMap function adds GEMport to ONU map
+func (f *OpenOltFlowMgr) addGemPortToOnuInfoMap(ctx context.Context, intfID uint32, onuID uint32, gemPort uint32) {
+
+	f.onuGemInfoLock.Lock()
+	defer f.onuGemInfoLock.Unlock()
+
+	logger.Infow(ctx, "adding-gem-to-onu-info-map",
+		log.Fields{
+			"gem-port-id": gemPort,
+			"intf-id":     intfID,
+			"onu-id":      onuID,
+			"device-id":   f.deviceHandler.device.Id,
+			"onu-gem":     f.onuGemInfo[intfID]})
+	onugem := f.onuGemInfo[intfID]
+	for idx, onu := range onugem {
+		if onu.OnuID == onuID {
+			// check if gem already exists , else update the cache and kvstore
+			for _, gem := range onu.GemPorts {
+				if gem == gemPort {
+					logger.Debugw(ctx, "gem-already-in-cache-no-need-to-update-cache-and-kv-store",
+						log.Fields{
+							"gem":       gemPort,
+							"device-id": f.deviceHandler.device.Id})
+					return
+				}
+			}
+			onugem[idx].GemPorts = append(onugem[idx].GemPorts, gemPort)
+			f.onuGemInfo[intfID] = onugem
+		}
+	}
+	err := f.resourceMgr.AddGemToOnuGemInfo(ctx, intfID, onuID, gemPort)
+	if err != nil {
+		logger.Errorw(ctx, "failed-to-add-gem-to-onu",
+			log.Fields{
+				"intf-id":   intfID,
+				"onu-id":    onuID,
+				"gemPort":   gemPort,
+				"device-id": f.deviceHandler.device.Id})
+		return
+	}
+	logger.Infow(ctx, "gem-added-to-onu-info-map",
+		log.Fields{
+			"gem-port-id": gemPort,
+			"intf-id":     intfID,
+			"onu-id":      onuID,
+			"device-id":   f.deviceHandler.device.Id,
+			"onu-gem":     f.onuGemInfo[intfID]})
+}
+
+// This function Lookup maps  by serialNumber or (intfId, gemPort)
+
+//getOnuIDfromGemPortMap Returns OnuID,nil if found or set 0,error if no onuId is found for serialNumber or (intfId, gemPort)
+func (f *OpenOltFlowMgr) getOnuIDfromGemPortMap(ctx context.Context, intfID uint32, gemPortID uint32) (uint32, error) {
+
+	f.onuGemInfoLock.RLock()
+	defer f.onuGemInfoLock.RUnlock()
+
+	logger.Infow(ctx, "getting-onu-id-from-gem-port-and-pon-port",
+		log.Fields{
+			"device-id":   f.deviceHandler.device.Id,
+			"onu-geminfo": f.onuGemInfo[intfID],
+			"intf-id":     intfID,
+			"gemport-id":  gemPortID})
+
+	onugem := f.onuGemInfo[intfID]
+
+	for _, onu := range onugem {
+		for _, gem := range onu.GemPorts {
+			if gem == gemPortID {
+				return onu.OnuID, nil
+			}
+		}
+	}
+	logger.Errorw(ctx, "onu-id-from-gem-port-not-found", log.Fields{
+		"gem-port-id":      gemPortID,
+		"interface-id":     intfID,
+		"all-gems-on-port": onugem,
+	})
+	return uint32(0), olterrors.NewErrNotFound("onu-id", log.Fields{
+		"interface-id": intfID,
+		"gem-port-id":  gemPortID},
+		nil)
+}
+
+//GetLogicalPortFromPacketIn function computes logical port UNI/NNI port from packet-in indication and returns the same
+func (f *OpenOltFlowMgr) GetLogicalPortFromPacketIn(ctx context.Context, packetIn *openoltpb2.PacketIndication) (uint32, error) {
+	var logicalPortNum uint32
+	var onuID uint32
+	var err error
+
+	if packetIn.IntfType == "pon" {
+		// packet indication does not have serial number , so sending as nil
+		if onuID, err = f.getOnuIDfromGemPortMap(ctx, packetIn.IntfId, packetIn.GemportId); err != nil {
+			// Called method is returning error with all data populated; just return the same
+			return logicalPortNum, err
+		}
+		if packetIn.PortNo != 0 {
+			logicalPortNum = packetIn.PortNo
+		} else {
+			uniID := uint32(0) //  FIXME - multi-uni support
+			logicalPortNum = MkUniPortNum(ctx, packetIn.IntfId, onuID, uniID)
+		}
+		// Store the gem port through which the packet_in came. Use the same gem port for packet_out
+		f.UpdateGemPortForPktIn(ctx, packetIn.IntfId, onuID, logicalPortNum, packetIn.GemportId, packetIn.Pkt)
+	} else if packetIn.IntfType == "nni" {
+		logicalPortNum = IntfIDToPortNo(packetIn.IntfId, voltha.Port_ETHERNET_NNI)
+	}
+	logger.Infow(ctx, "retrieved-logicalport-from-packet-in",
+		log.Fields{
+			"logical-port-num": logicalPortNum,
+			"intf-type":        packetIn.IntfType,
+			"packet":           hex.EncodeToString(packetIn.Pkt),
+		})
+	return logicalPortNum, nil
+}
+
+//GetPacketOutGemPortID returns gemPortId
+func (f *OpenOltFlowMgr) GetPacketOutGemPortID(ctx context.Context, intfID uint32, onuID uint32, portNum uint32, packet []byte) (uint32, error) {
+	var gemPortID uint32
+
+	ctag, priority, err := getCTagFromPacket(ctx, packet)
+	if err != nil {
+		return 0, err
+	}
+
+	f.onuGemInfoLock.RLock()
+	defer f.onuGemInfoLock.RUnlock()
+	pktInkey := rsrcMgr.PacketInInfoKey{IntfID: intfID, OnuID: onuID, LogicalPort: portNum, VlanID: ctag, Priority: priority}
+	var ok bool
+	gemPortID, ok = f.packetInGemPort[pktInkey]
+	if ok {
+		logger.Debugw(ctx, "found-gemport-for-pktin-key",
+			log.Fields{
+				"pktinkey": pktInkey,
+				"gem":      gemPortID})
+
+		return gemPortID, nil
+	}
+	gemPortID, err = f.resourceMgr.GetGemPortFromOnuPktIn(ctx, pktInkey)
+	if err == nil {
+		if gemPortID != 0 {
+			f.packetInGemPort[pktInkey] = gemPortID
+			logger.Infow(ctx, "found-gem-port-from-kv-store-and-updating-cache-with-gemport",
+				log.Fields{
+					"pktinkey": pktInkey,
+					"gem":      gemPortID})
+			return gemPortID, nil
+		}
+	}
+	return uint32(0), olterrors.NewErrNotFound("gem-port",
+		log.Fields{
+			"pktinkey": pktInkey,
+			"gem":      gemPortID}, err)
+
+}
+
+// nolint: gocyclo
+func installFlowOnAllGemports(ctx context.Context,
+	f1 func(ctx context.Context, intfId uint32, onuId uint32, uniId uint32,
+		portNo uint32, classifier map[string]interface{}, action map[string]interface{},
+		logicalFlow *ofp.OfpFlowStats, allocId uint32, gemPortId uint32, tpID uint32) error,
+	f2 func(ctx context.Context, intfId uint32, onuId uint32, uniId uint32, portNo uint32,
+		classifier map[string]interface{}, action map[string]interface{},
+		logicalFlow *ofp.OfpFlowStats, allocId uint32, gemPortId uint32, vlanId uint32,
+		tpID uint32) error,
+	args map[string]uint32,
+	classifier map[string]interface{}, action map[string]interface{},
+	logicalFlow *ofp.OfpFlowStats,
+	gemPorts []uint32,
+	TpInst interface{},
+	FlowType string,
+	direction string,
+	tpID uint32,
+	vlanID ...uint32) {
+	logger.Debugw(ctx, "installing-flow-on-all-gem-ports",
+		log.Fields{
+			"FlowType": FlowType,
+			"gemPorts": gemPorts,
+			"vlan":     vlanID})
+
+
+
+	switch TpInst := TpInst.(type) {
+	case *tp.TechProfile:
+		attributes := TpInst.DownstreamGemPortAttributeList
+		if direction == Upstream {
+			attributes = TpInst.UpstreamGemPortAttributeList
+		}
+
+		for _, gemPortAttribute := range attributes {
+			if direction == Downstream && strings.ToUpper(gemPortAttribute.IsMulticast) == "TRUE" {
+				continue
+			}
+			gemPortID := gemPortAttribute.GemportID
+			if allPbitsMarked(gemPortAttribute.PbitMap) {
+				classifier[VlanPcp] = uint32(VlanPCPMask)
+				if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+					if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+						logger.Warn(ctx, err)
+					}
+				} else if FlowType == EapolFlow {
+					if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+						logger.Warn(ctx, err)
+					}
+				}
+			} else {
+				for pos, pbitSet := range strings.TrimPrefix(gemPortAttribute.PbitMap, BinaryStringPrefix) {
+					if pbitSet == BinaryBit1 {
+						classifier[VlanPcp] = uint32(len(strings.TrimPrefix(gemPortAttribute.PbitMap, BinaryStringPrefix))) - 1 - uint32(pos)
+						if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+							if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+								logger.Warn(ctx, err)
+							}
+						} else if FlowType == EapolFlow {
+							if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+								logger.Warn(ctx, err)
+							}
+						}
+					}
+				}
+			}
+		}
+	case *tp.EponProfile:
+		if direction == Upstream {
+			attributes := TpInst.UpstreamQueueAttributeList
+			for _, queueAttribute := range attributes {
+				gemPortID := queueAttribute.GemportID
+				if allPbitsMarked(queueAttribute.PbitMap) {
+					classifier[VlanPcp] = uint32(VlanPCPMask)
+					if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+						if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+							logger.Warn(ctx, err)
+						}
+					} else if FlowType == EapolFlow {
+						if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+							logger.Warn(ctx, err)
+						}
+					}
+				} else {
+					for pos, pbitSet := range strings.TrimPrefix(queueAttribute.PbitMap, BinaryStringPrefix) {
+						if pbitSet == BinaryBit1 {
+							classifier[VlanPcp] = uint32(len(strings.TrimPrefix(queueAttribute.PbitMap, BinaryStringPrefix))) - 1 - uint32(pos)
+							if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+								if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+									logger.Warn(ctx, err)
+								}
+							} else if FlowType == EapolFlow {
+								if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+									logger.Warn(ctx, err)
+								}
+							}
+						}
+					}
+				}
+			}
+		} else {
+			attributes := TpInst.DownstreamQueueAttributeList
+			for _, queueAttribute := range attributes {
+				gemPortID := queueAttribute.GemportID
+				if allPbitsMarked(queueAttribute.PbitMap) {
+					classifier[VlanPcp] = uint32(VlanPCPMask)
+					if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+						if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+							logger.Warn(ctx, err)
+						}
+					} else if FlowType == EapolFlow {
+						if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+							logger.Warn(ctx, err)
+						}
+					}
+				} else {
+					for pos, pbitSet := range strings.TrimPrefix(queueAttribute.PbitMap, BinaryStringPrefix) {
+						if pbitSet == BinaryBit1 {
+							classifier[VlanPcp] = uint32(len(strings.TrimPrefix(queueAttribute.PbitMap, BinaryStringPrefix))) - 1 - uint32(pos)
+							if FlowType == DhcpFlow || FlowType == IgmpFlow || FlowType == HsiaFlow {
+								if err := f1(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, tpID); err != nil {
+									logger.Warn(ctx, err)
+								}
+							} else if FlowType == EapolFlow {
+								if err := f2(ctx, args["intfId"], args["onuId"], args["uniId"], args["portNo"], classifier, action, logicalFlow, args["allocId"], gemPortID, vlanID[0], tpID); err != nil {
+									logger.Warn(ctx, err)
+								}
+							}
+						}
+					}
+				}
+			}
+		}
+	default:
+		logger.Errorw(ctx, "unknown-tech", log.Fields{"tpInst": TpInst})
+	}
+}
+
+func allPbitsMarked(pbitMap string) bool {
+	for pos, pBit := range pbitMap {
+		if pos >= 2 && pBit != BinaryBit1 {
+			return false
+		}
+	}
+	return true
+}
+
+func (f *OpenOltFlowMgr) addDHCPTrapFlowOnNNI(ctx context.Context, logicalFlow *ofp.OfpFlowStats, classifier map[string]interface{}, portNo uint32) error {
+	logger.Debug(ctx, "adding-trap-dhcp-of-nni-flow")
+	action := make(map[string]interface{})
+	classifier[PacketTagType] = DoubleTag
+	action[TrapToHost] = true
+	/* We manage flowId resource pool on per PON port basis.
+	   Since this situation is tricky, as a hack, we pass the NNI port
+	   index (network_intf_id) as PON port Index for the flowId resource
+	   pool. Also, there is no ONU Id available for trapping DHCP packets
+	   on NNI port, use onu_id as -1 (invalid)
+	   ****************** CAVEAT *******************
+	   This logic works if the NNI Port Id falls within the same valid
+	   range of PON Port Ids. If this doesn't work for some OLT Vendor
+	   we need to have a re-look at this.
+	   *********************************************
+	*/
+	onuID := -1
+	uniID := -1
+	gemPortID := -1
+	allocID := -1
+	networkInterfaceID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-intreface-id",
+			log.Fields{
+				"classifier": classifier,
+				"action":     action},
+			err)
+	}
+
+	flowStoreCookie := getFlowStoreCookie(ctx, classifier, uint32(0))
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Info(ctx, "flow-exists-not-re-adding")
+		return nil
+	}
+	flowID, err := f.resourceMgr.GetFlowID(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), uint32(gemPortID), flowStoreCookie, "", 0, 0)
+	if err != nil {
+		return olterrors.NewErrNotFound("dhcp-trap-nni-flow-id",
+			log.Fields{
+				"interface-id": networkInterfaceID,
+				"onu-id":       onuID,
+				"uni-id":       uniID,
+				"gem-port-id":  gemPortID,
+				"cookie":       flowStoreCookie},
+			err)
+	}
+	classifierProto, err := makeOpenOltClassifierField(classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifier}, err)
+	}
+	logger.Debugw(ctx, "created-classifier-proto", log.Fields{"classifier": *classifierProto})
+	actionProto, err := makeOpenOltActionField(action, classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": action}, err)
+	}
+	logger.Debugw(ctx, "created-action-proto", log.Fields{"action": *actionProto})
+	downstreamflow := openoltpb2.Flow{AccessIntfId: int32(-1), // AccessIntfId not required
+		OnuId:         int32(onuID), // OnuId not required
+		UniId:         int32(uniID), // UniId not used
+		FlowId:        flowID,
+		FlowType:      Downstream,
+		AllocId:       int32(allocID), // AllocId not used
+		NetworkIntfId: int32(networkInterfaceID),
+		GemportId:     int32(gemPortID), // GemportId not used
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo}
+	if err := f.addFlowToDevice(ctx, logicalFlow, &downstreamflow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, log.Fields{"flow": downstreamflow}, err)
+	}
+	logger.Info(ctx, "dhcp-trap-on-nni-flow-added–to-device-successfully")
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &downstreamflow, flowStoreCookie, "", flowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, int32(networkInterfaceID),
+		int32(onuID),
+		int32(uniID),
+		flowID, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flowID, log.Fields{"flow": downstreamflow}, err)
+	}
+	return nil
+}
+
+//getPacketTypeFromClassifiers finds and returns packet type of a flow by checking flow classifiers
+func getPacketTypeFromClassifiers(classifierInfo map[string]interface{}) string {
+	var packetType string
+	ovid, ivid := false, false
+	if vlanID, ok := classifierInfo[VlanVid].(uint32); ok {
+		vid := vlanID & VlanvIDMask
+		if vid != ReservedVlan {
+			ovid = true
+		}
+	}
+	if metadata, ok := classifierInfo[Metadata].(uint64); ok {
+		vid := uint32(metadata)
+		if vid != ReservedVlan {
+			ivid = true
+		}
+	}
+	if ovid && ivid {
+		packetType = DoubleTag
+	} else if !ovid && !ivid {
+		packetType = Untagged
+	} else {
+		packetType = SingleTag
+	}
+	return packetType
+}
+
+//addIgmpTrapFlowOnNNI adds a trap-to-host flow on NNI
+func (f *OpenOltFlowMgr) addIgmpTrapFlowOnNNI(ctx context.Context, logicalFlow *ofp.OfpFlowStats, classifier map[string]interface{}, portNo uint32) error {
+	logger.Infow(ctx, "adding-igmp-trap-of-nni-flow", log.Fields{"classifier-info": classifier})
+	action := make(map[string]interface{})
+	classifier[PacketTagType] = getPacketTypeFromClassifiers(classifier)
+	action[TrapToHost] = true
+	/* We manage flowId resource pool on per PON port basis.
+	   Since this situation is tricky, as a hack, we pass the NNI port
+	   index (network_intf_id) as PON port Index for the flowId resource
+	   pool. Also, there is no ONU Id available for trapping packets
+	   on NNI port, use onu_id as -1 (invalid)
+	   ****************** CAVEAT *******************
+	   This logic works if the NNI Port Id falls within the same valid
+	   range of PON Port Ids. If this doesn't work for some OLT Vendor
+	   we need to have a re-look at this.
+	   *********************************************
+	*/
+	onuID := -1
+	uniID := -1
+	gemPortID := -1
+	allocID := -1
+	networkInterfaceID, err := getNniIntfID(ctx, classifier, action)
+	if err != nil {
+		return olterrors.NewErrNotFound("nni-interface-id", log.Fields{
+			"classifier": classifier,
+			"action":     action},
+			err)
+	}
+	flowStoreCookie := getFlowStoreCookie(ctx, classifier, uint32(0))
+	if present := f.resourceMgr.IsFlowCookieOnKVStore(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), flowStoreCookie); present {
+		logger.Info(ctx, "igmp-flow-exists-not-re-adding")
+		return nil
+	}
+	flowID, err := f.resourceMgr.GetFlowID(ctx, uint32(networkInterfaceID), int32(onuID), int32(uniID), uint32(gemPortID), flowStoreCookie, "", 0, 0)
+	if err != nil {
+		return olterrors.NewErrNotFound("igmp-flow-id",
+			log.Fields{
+				"interface-id": networkInterfaceID,
+				"onu-id":       onuID,
+				"uni-id":       uniID,
+				"gem-port-id":  gemPortID,
+				"cookie":       flowStoreCookie},
+			err)
+	}
+	classifierProto, err := makeOpenOltClassifierField(classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"classifier": classifier}, err)
+	}
+	logger.Debugw(ctx, "created-classifier-proto-for-the-igmp-flow", log.Fields{"classifier": *classifierProto})
+	actionProto, err := makeOpenOltActionField(action, classifier)
+	if err != nil {
+		return olterrors.NewErrInvalidValue(log.Fields{"action": action}, err)
+	}
+	logger.Debugw(ctx, "created-action-proto-for-the-igmp-flow", log.Fields{"action": *actionProto})
+	downstreamflow := openoltpb2.Flow{AccessIntfId: int32(-1), // AccessIntfId not required
+		OnuId:         int32(onuID), // OnuId not required
+		UniId:         int32(uniID), // UniId not used
+		FlowId:        flowID,
+		FlowType:      Downstream,
+		AllocId:       int32(allocID), // AllocId not used
+		NetworkIntfId: int32(networkInterfaceID),
+		GemportId:     int32(gemPortID), // GemportId not used
+		Classifier:    classifierProto,
+		Action:        actionProto,
+		Priority:      int32(logicalFlow.Priority),
+		Cookie:        logicalFlow.Cookie,
+		PortNo:        portNo}
+	if err := f.addFlowToDevice(ctx, logicalFlow, &downstreamflow); err != nil {
+		return olterrors.NewErrFlowOp("add", flowID, log.Fields{"flow": downstreamflow}, err)
+	}
+	logger.Info(ctx, "igmp-trap-on-nni-flow-added-to-device-successfully")
+	flowsToKVStore := f.getUpdatedFlowInfo(ctx, &downstreamflow, flowStoreCookie, "", flowID, logicalFlow.Id)
+	if err := f.updateFlowInfoToKVStore(ctx, int32(networkInterfaceID),
+		int32(onuID),
+		int32(uniID),
+		flowID, flowsToKVStore); err != nil {
+		return olterrors.NewErrPersistence("update", "flow", flowID, log.Fields{"flow": downstreamflow}, err)
+	}
+	return nil
+}
+
+func verifyMeterIDAndGetDirection(MeterID uint32, Dir tp_pb.Direction) (string, error) {
+	if MeterID == 0 { // This should never happen
+		return "", olterrors.NewErrInvalidValue(log.Fields{"meter-id": MeterID}, nil).Log()
+	}
+	if Dir == tp_pb.Direction_UPSTREAM {
+		return "upstream", nil
+	} else if Dir == tp_pb.Direction_DOWNSTREAM {
+		return "downstream", nil
+	}
+	return "", nil
+}
+
+// nolint: gocyclo
+func (f *OpenOltFlowMgr) checkAndAddFlow(ctx context.Context, args map[string]uint32, classifierInfo map[string]interface{},
+	actionInfo map[string]interface{}, flow *ofp.OfpFlowStats, TpInst interface{}, gemPorts []uint32,
+	tpID uint32, uni string) {
+	var gemPort uint32
+	intfID := args[IntfID]
+	onuID := args[OnuID]
+	uniID := args[UniID]
+	portNo := args[PortNo]
+	allocID := args[AllocID]
+	if ipProto, ok := classifierInfo[IPProto]; ok {
+		if ipProto.(uint32) == IPProtoDhcp {
+			logger.Infow(ctx, "adding-dhcp-flow", log.Fields{
+				"tp-id":    tpID,
+				"alloc-id": allocID,
+				"intf-id":  intfID,
+				"onu-id":   onuID,
+				"uni-id":   uniID,
+			})
+			if pcp, ok := classifierInfo[VlanPcp]; ok {
+				gemPort = f.techprofile[intfID].GetGemportIDForPbit(ctx, TpInst,
+					tp_pb.Direction_UPSTREAM,
+					pcp.(uint32))
+				//Adding DHCP upstream flow
+
+				if err := f.addDHCPTrapFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, allocID, gemPort, tpID); err != nil {
+					logger.Warn(ctx, err)
+				}
+			} else {
+				//Adding DHCP upstream flow to all gemports
+				installFlowOnAllGemports(ctx, f.addDHCPTrapFlow, nil, args, classifierInfo, actionInfo, flow, gemPorts, TpInst, DhcpFlow, Upstream, tpID)
+			}
+
+		} else if ipProto.(uint32) == IgmpProto {
+			logger.Infow(ctx, "adding-us-igmp-flow",
+				log.Fields{
+					"intf-id":          intfID,
+					"onu-id":           onuID,
+					"uni-id":           uniID,
+					"classifier-info:": classifierInfo})
+			if pcp, ok := classifierInfo[VlanPcp]; ok {
+				gemPort = f.techprofile[intfID].GetGemportIDForPbit(ctx, TpInst,
+					tp_pb.Direction_UPSTREAM,
+					pcp.(uint32))
+				if err := f.addIGMPTrapFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, allocID, gemPort, tpID); err != nil {
+					logger.Warn(ctx, err)
+				}
+			} else {
+				//Adding IGMP upstream flow to all gem ports
+				installFlowOnAllGemports(ctx, f.addIGMPTrapFlow, nil, args, classifierInfo, actionInfo, flow, gemPorts, TpInst, IgmpFlow, Upstream, tpID)
+			}
+		} else {
+			logger.Errorw(ctx, "invalid-classifier-to-handle", log.Fields{"classifier": classifierInfo, "action": actionInfo})
+			return
+		}
+	} else if ethType, ok := classifierInfo[EthType]; ok {
+		if ethType.(uint32) == EapEthType {
+			logger.Infow(ctx, "adding-eapol-flow", log.Fields{
+				"intf-id": intfID,
+				"onu-id":  onuID,
+				"uni-id":  uniID,
+			})
+			var vlanID uint32
+			if val, ok := classifierInfo[VlanVid]; ok {
+				vlanID = (val.(uint32)) & VlanvIDMask
+			} else {
+				vlanID = DefaultMgmtVlan
+			}
+			if pcp, ok := classifierInfo[VlanPcp]; ok {
+				gemPort = f.techprofile[intfID].GetGemportIDForPbit(ctx, TpInst,
+					tp_pb.Direction_UPSTREAM,
+					pcp.(uint32))
+
+				if err := f.addEAPOLFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, allocID, gemPort, vlanID, tpID); err != nil {
+					logger.Warn(ctx, err)
+				}
+			} else {
+				installFlowOnAllGemports(ctx, nil, f.addEAPOLFlow, args, classifierInfo, actionInfo, flow, gemPorts, TpInst, EapolFlow, Upstream, tpID, vlanID)
+			}
+		}
+	} else if _, ok := actionInfo[PushVlan]; ok {
+		logger.Infow(ctx, "adding-upstream-data-rule", log.Fields{
+			"intf-id": intfID,
+			"onu-id":  onuID,
+			"uni-id":  uniID,
+		})
+		if pcp, ok := classifierInfo[VlanPcp]; ok {
+			gemPort = f.techprofile[intfID].GetGemportIDForPbit(ctx, TpInst,
+				tp_pb.Direction_UPSTREAM,
+				pcp.(uint32))
+			//Adding HSIA upstream flow
+			if err := f.addUpstreamDataFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, allocID, gemPort, tpID); err != nil {
+				logger.Warn(ctx, err)
+			}
+		} else {
+			//Adding HSIA upstream flow to all gemports
+			installFlowOnAllGemports(ctx, f.addUpstreamDataFlow, nil, args, classifierInfo, actionInfo, flow, gemPorts, TpInst, HsiaFlow, Upstream, tpID)
+		}
+	} else if _, ok := actionInfo[PopVlan]; ok {
+		logger.Infow(ctx, "adding-downstream-data-rule", log.Fields{
+			"intf-id": intfID,
+			"onu-id":  onuID,
+			"uni-id":  uniID,
+		})
+		if pcp, ok := classifierInfo[VlanPcp]; ok {
+			gemPort = f.techprofile[intfID].GetGemportIDForPbit(ctx, TpInst,
+				tp_pb.Direction_DOWNSTREAM,
+				pcp.(uint32))
+			//Adding HSIA downstream flow
+			if err := f.addDownstreamDataFlow(ctx, intfID, onuID, uniID, portNo, classifierInfo, actionInfo, flow, allocID, gemPort, tpID); err != nil {
+				logger.Warn(ctx, err)
+			}
+		} else {
+			//Adding HSIA downstream flow to all gemports
+			installFlowOnAllGemports(ctx, f.addDownstreamDataFlow, nil, args, classifierInfo, actionInfo, flow, gemPorts, TpInst, HsiaFlow, Downstream, tpID)
+		}
+	} else {
+		logger.Errorw(ctx, "invalid-flow-type-to-handle",
+			log.Fields{
+				"intf-id":    intfID,
+				"onu-id":     onuID,
+				"uni-id":     uniID,
+				"classifier": classifierInfo,
+				"action":     actionInfo,
+				"flow":       flow})
+		return
+	}
+	if noticeDownloadRequest {
+		go func() {
+			if err := f.sendTPDownloadMsgToChild(ctx, intfID, onuID, uniID, uni, tpID); err != nil {
+				logger.Warn(ctx, err)
+			}
+		}()
+	}
+}
+
+func (f *OpenOltFlowMgr) isGemPortUsedByAnotherFlow(ctx context.Context, gemPK gemPortKey) (bool, error) {
+	if f.perGemPortLock.TryLock(gemPK) {
+		flowIDList := f.flowsUsedByGemPort[gemPK]
+		f.perGemPortLock.Unlock(gemPK)
+		return len(flowIDList) > 1, nil
+	}
+	logger.Error(ctx, "failed-to-acquire-per-gem-port-lock",
+		log.Fields{
+			"device-id": f.deviceHandler.device.Id,
+			"key":       gemPK,
+		})
+	return false, olterrors.NewErrAdapter("failed-to-acquire-per-gem-port-lock", log.Fields{
+		"device-id": f.deviceHandler.device.Id,
+		"key":       gemPK,
+	}, nil)
+}
+
+func (f *OpenOltFlowMgr) isTechProfileUsedByAnotherGem(ctx context.Context, ponIntf uint32, onuID uint32, uniID uint32, tpID uint32, tpInst *tp.TechProfile, gemPortID uint32) (bool, uint32) {
+	currentGemPorts := f.resourceMgr.GetCurrentGEMPortIDsForOnu(ctx, ponIntf, onuID, uniID)
+	tpGemPorts := tpInst.UpstreamGemPortAttributeList
+	for _, currentGemPort := range currentGemPorts {
+		for _, tpGemPort := range tpGemPorts {
+			if (currentGemPort == tpGemPort.GemportID) && (currentGemPort != gemPortID) {
+				return true, currentGemPort
+			}
+		}
+	}
+	if tpInst.InstanceCtrl.Onu == "single-instance" {
+		// The TP information for the given TP ID, PON ID, ONU ID, UNI ID should be removed.
+		if err := f.resourceMgr.RemoveTechProfileIDForOnu(ctx, ponIntf, uint32(onuID), uint32(uniID), tpID); err != nil {
+			logger.Warn(ctx, err)
+		}
+		if err := f.DeleteTechProfileInstance(ctx, ponIntf, uint32(onuID), uint32(uniID), "", tpID); err != nil {
+			logger.Warn(ctx, err)
+		}
+
+		// Although we cleaned up TP Instance for the given (PON ID, ONU ID, UNI ID), the TP might
+		// still be used on other uni ports.
+		// So, we need to check and make sure that no other gem port is referring to the given TP ID
+		// on any other uni port.
+		tpInstances := f.techprofile[ponIntf].FindAllTpInstances(ctx, tpID, ponIntf, onuID).([]tp.TechProfile)
+		logger.Debugw(ctx, "got-single-instance-tp-instances", log.Fields{"tp-instances": tpInstances})
+		for i := 0; i < len(tpInstances); i++ {
+			tpI := tpInstances[i]
+			tpGemPorts := tpI.UpstreamGemPortAttributeList
+			for _, tpGemPort := range tpGemPorts {
+				if tpGemPort.GemportID != gemPortID {
+					logger.Debugw(ctx, "single-instance-tp-is-in-use-by-gem", log.Fields{"gemPort": tpGemPort.GemportID})
+					return true, tpGemPort.GemportID
+				}
+			}
+		}
+	}
+	logger.Debug(ctx, "tech-profile-is-not-in-use-by-any-gem")
+	return false, 0
+}
+
+func formulateClassifierInfoFromFlow(ctx context.Context, classifierInfo map[string]interface{}, flow *ofp.OfpFlowStats) {
+	for _, field := range flows.GetOfbFields(flow) {
+		if field.Type == flows.ETH_TYPE {
+			classifierInfo[EthType] = field.GetEthType()
+			logger.Debug(ctx, "field-type-eth-type", log.Fields{"classifierInfo[ETH_TYPE]": classifierInfo[EthType].(uint32)})
+		} else if field.Type == flows.ETH_DST {
+			classifierInfo[EthDst] = field.GetEthDst()
+			logger.Debug(ctx, "field-type-eth-type", log.Fields{"classifierInfo[ETH_DST]": classifierInfo[EthDst].([]uint8)})
+		} else if field.Type == flows.IP_PROTO {
+			classifierInfo[IPProto] = field.GetIpProto()
+			logger.Debug(ctx, "field-type-ip-proto", log.Fields{"classifierInfo[IP_PROTO]": classifierInfo[IPProto].(uint32)})
+		} else if field.Type == flows.IN_PORT {
+			classifierInfo[InPort] = field.GetPort()
+			logger.Debug(ctx, "field-type-in-port", log.Fields{"classifierInfo[IN_PORT]": classifierInfo[InPort].(uint32)})
+		} else if field.Type == flows.VLAN_VID {
+			classifierInfo[VlanVid] = field.GetVlanVid() & 0xfff
+			logger.Debug(ctx, "field-type-vlan-vid", log.Fields{"classifierInfo[VLAN_VID]": classifierInfo[VlanVid].(uint32)})
+		} else if field.Type == flows.VLAN_PCP {
+			classifierInfo[VlanPcp] = field.GetVlanPcp()
+			logger.Debug(ctx, "field-type-vlan-pcp", log.Fields{"classifierInfo[VLAN_PCP]": classifierInfo[VlanPcp].(uint32)})
+		} else if field.Type == flows.UDP_DST {
+			classifierInfo[UDPDst] = field.GetUdpDst()
+			logger.Debug(ctx, "field-type-udp-dst", log.Fields{"classifierInfo[UDP_DST]": classifierInfo[UDPDst].(uint32)})
+		} else if field.Type == flows.UDP_SRC {
+			classifierInfo[UDPSrc] = field.GetUdpSrc()
+			logger.Debug(ctx, "field-type-udp-src", log.Fields{"classifierInfo[UDP_SRC]": classifierInfo[UDPSrc].(uint32)})
+		} else if field.Type == flows.IPV4_DST {
+			classifierInfo[Ipv4Dst] = field.GetIpv4Dst()
+			logger.Debug(ctx, "field-type-ipv4-dst", log.Fields{"classifierInfo[IPV4_DST]": classifierInfo[Ipv4Dst].(uint32)})
+		} else if field.Type == flows.IPV4_SRC {
+			classifierInfo[Ipv4Src] = field.GetIpv4Src()
+			logger.Debug(ctx, "field-type-ipv4-src", log.Fields{"classifierInfo[IPV4_SRC]": classifierInfo[Ipv4Src].(uint32)})
+		} else if field.Type == flows.METADATA {
+			classifierInfo[Metadata] = field.GetTableMetadata()
+			logger.Debug(ctx, "field-type-metadata", log.Fields{"classifierInfo[Metadata]": classifierInfo[Metadata].(uint64)})
+		} else if field.Type == flows.TUNNEL_ID {
+			classifierInfo[TunnelID] = field.GetTunnelId()
+			logger.Debug(ctx, "field-type-tunnelId", log.Fields{"classifierInfo[TUNNEL_ID]": classifierInfo[TunnelID].(uint64)})
+		} else {
+			logger.Errorw(ctx, "un-supported-field-type", log.Fields{"type": field.Type})
+			return
+		}
+	}
+}
+
+func formulateActionInfoFromFlow(ctx context.Context, actionInfo, classifierInfo map[string]interface{}, flow *ofp.OfpFlowStats) error {
+	for _, action := range flows.GetActions(flow) {
+		if action.Type == flows.OUTPUT {
+			if out := action.GetOutput(); out != nil {
+				actionInfo[Output] = out.GetPort()
+				logger.Debugw(ctx, "action-type-output", log.Fields{"out-port": actionInfo[Output].(uint32)})
+			} else {
+				return olterrors.NewErrInvalidValue(log.Fields{"output-port": nil}, nil)
+			}
+		} else if action.Type == flows.POP_VLAN {
+			actionInfo[PopVlan] = true
+			logger.Debugw(ctx, "action-type-pop-vlan", log.Fields{"in_port": classifierInfo[InPort].(uint32)})
+		} else if action.Type == flows.PUSH_VLAN {
+			if out := action.GetPush(); out != nil {
+				if tpid := out.GetEthertype(); tpid != 0x8100 {
+					logger.Errorw(ctx, "invalid ethertype in push action", log.Fields{"ethertype": actionInfo[PushVlan].(int32)})
+				} else {
+					actionInfo[PushVlan] = true
+					actionInfo[TPID] = tpid
+					logger.Debugw(ctx, "action-type-push-vlan",
+						log.Fields{
+							"push-tpid": actionInfo[TPID].(uint32),
+							"in-port":   classifierInfo[InPort].(uint32)})
+				}
+			}
+		} else if action.Type == flows.SET_FIELD {
+			if out := action.GetSetField(); out != nil {
+				if field := out.GetField(); field != nil {
+					if ofClass := field.GetOxmClass(); ofClass != ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC {
+						return olterrors.NewErrInvalidValue(log.Fields{"openflow-class": ofClass}, nil)
+					}
+					/*logger.Debugw(ctx, "action-type-set-field",log.Fields{"field": field, "in_port": classifierInfo[IN_PORT].(uint32)})*/
+					formulateSetFieldActionInfoFromFlow(ctx, field, actionInfo)
+				}
+			}
+		} else if action.Type == flows.GROUP {
+			formulateGroupActionInfoFromFlow(ctx, action, actionInfo)
+		} else {
+			return olterrors.NewErrInvalidValue(log.Fields{"action-type": action.Type}, nil)
+		}
+	}
+	return nil
+}
+
+func formulateSetFieldActionInfoFromFlow(ctx context.Context, field *ofp.OfpOxmField, actionInfo map[string]interface{}) {
+	if ofbField := field.GetOfbField(); ofbField != nil {
+		fieldtype := ofbField.GetType()
+		if fieldtype == ofp.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_VID {
+			if vlan := ofbField.GetVlanVid(); vlan != 0 {
+				actionInfo[VlanVid] = vlan & 0xfff
+				logger.Debugw(ctx, "action-set-vlan-vid", log.Fields{"actionInfo[VLAN_VID]": actionInfo[VlanVid].(uint32)})
+			} else {
+				logger.Error(ctx, "no-invalid-vlan-id-in-set-vlan-vid-action")
+			}
+		} else if fieldtype == ofp.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_PCP {
+			pcp := ofbField.GetVlanPcp()
+			actionInfo[VlanPcp] = pcp
+			logger.Debugw(ctx, "action-set-vlan-pcp", log.Fields{"actionInfo[VLAN_PCP]": actionInfo[VlanPcp].(uint32)})
+		} else {
+			logger.Errorw(ctx, "unsupported-action-set-field-type", log.Fields{"type": fieldtype})
+		}
+	}
+}
+
+func formulateGroupActionInfoFromFlow(ctx context.Context, action *ofp.OfpAction, actionInfo map[string]interface{}) {
+	if action.GetGroup() == nil {
+		logger.Warn(ctx, "no-group-entry-found-in-the-group-action")
+	} else {
+		actionInfo[GroupID] = action.GetGroup().GroupId
+		logger.Debugw(ctx, "action-group-id", log.Fields{"actionInfo[GroupID]": actionInfo[GroupID].(uint32)})
+	}
+}
+
+func formulateControllerBoundTrapFlowInfo(ctx context.Context, actionInfo, classifierInfo map[string]interface{}, flow *ofp.OfpFlowStats) error {
+	if isControllerFlow := IsControllerBoundFlow(actionInfo[Output].(uint32)); isControllerFlow {
+		logger.Debug(ctx, "controller-bound-trap-flows--getting-inport-from-tunnelid")
+		/* Get UNI port/ IN Port from tunnel ID field for upstream controller bound flows  */
+		if portType := IntfIDToPortTypeName(classifierInfo[InPort].(uint32)); portType == voltha.Port_PON_OLT {
+			if uniPort := flows.GetChildPortFromTunnelId(flow); uniPort != 0 {
+				classifierInfo[InPort] = uniPort
+				logger.Debugw(ctx, "upstream-pon-to-controller-flow--inport-in-tunnelid",
+					log.Fields{
+						"newinport": classifierInfo[InPort].(uint32),
+						"outport":   actionInfo[Output].(uint32)})
+			} else {
+				return olterrors.NewErrNotFound("child-in-port",
+					log.Fields{
+						"reason": "upstream-pon-to-controller-flow--no-inport-in-tunnelid",
+						"flow":   flow}, nil)
+			}
+		}
+	} else {
+		logger.Debug(ctx, "non-controller-flows--getting-uniport-from-tunnelid")
+		// Downstream flow from NNI to PON port , Use tunnel ID as new OUT port / UNI port
+		if portType := IntfIDToPortTypeName(actionInfo[Output].(uint32)); portType == voltha.Port_PON_OLT {
+			if uniPort := flows.GetChildPortFromTunnelId(flow); uniPort != 0 {
+				actionInfo[Output] = uniPort
+				logger.Debugw(ctx, "downstream-nni-to-pon-port-flow, outport-in-tunnelid",
+					log.Fields{
+						"newoutport": actionInfo[Output].(uint32),
+						"outport":    actionInfo[Output].(uint32)})
+			} else {
+				return olterrors.NewErrNotFound("out-port",
+					log.Fields{
+						"reason": "downstream-nni-to-pon-port-flow--no-outport-in-tunnelid",
+						"flow":   flow}, nil)
+			}
+			// Upstream flow from PON to NNI port , Use tunnel ID as new IN port / UNI port
+		} else if portType := IntfIDToPortTypeName(classifierInfo[InPort].(uint32)); portType == voltha.Port_PON_OLT {
+			if uniPort := flows.GetChildPortFromTunnelId(flow); uniPort != 0 {
+				classifierInfo[InPort] = uniPort
+				logger.Debugw(ctx, "upstream-pon-to-nni-port-flow, inport-in-tunnelid",
+					log.Fields{
+						"newinport": actionInfo[Output].(uint32),
+						"outport":   actionInfo[Output].(uint32)})
+			} else {
+				return olterrors.NewErrNotFound("nni-port",
+					log.Fields{
+						"reason":   "upstream-pon-to-nni-port-flow--no-inport-in-tunnelid",
+						"in-port":  classifierInfo[InPort].(uint32),
+						"out-port": actionInfo[Output].(uint32),
+						"flow":     flow}, nil)
+			}
+		}
+	}
+	return nil
+}
+
+func getTpIDFromFlow(ctx context.Context, flow *ofp.OfpFlowStats) (uint32, error) {
+	/*     Metadata 8 bytes:
+		   Most Significant 2 Bytes = Inner VLAN
+		   Next 2 Bytes = Tech Profile ID(TPID)
+		   Least Significant 4 Bytes = Port ID
+	       Flow Metadata carries Tech-Profile (TP) ID and is mandatory in all
+	       subscriber related flows.
+	*/
+	metadata := flows.GetMetadataFromWriteMetadataAction(ctx, flow)
+	if metadata == 0 {
+		return 0, olterrors.NewErrNotFound("metadata", log.Fields{"flow": flow}, nil)
+	}
+	TpID := flows.GetTechProfileIDFromWriteMetaData(ctx, metadata)
+	return uint32(TpID), nil
+}
+
+func appendUnique(slice []uint32, item uint32) []uint32 {
+	for _, sliceElement := range slice {
+		if sliceElement == item {
+			return slice
+		}
+	}
+	return append(slice, item)
+}
+
+// getNniIntfID gets nni intf id from the flow classifier/action
+func getNniIntfID(ctx context.Context, classifier map[string]interface{}, action map[string]interface{}) (uint32, error) {
+
+	portType := IntfIDToPortTypeName(classifier[InPort].(uint32))
+	if portType == voltha.Port_PON_OLT {
+		intfID, err := IntfIDFromNniPortNum(ctx, action[Output].(uint32))
+		if err != nil {
+			logger.Debugw(ctx, "invalid-action-port-number",
+				log.Fields{
+					"port-number": action[Output].(uint32),
+					"error":       err})
+			return uint32(0), err
+		}
+		logger.Infow(ctx, "output-nni-intfId-is", log.Fields{"intf-id": intfID})
+		return intfID, nil
+	} else if portType == voltha.Port_ETHERNET_NNI {
+		intfID, err := IntfIDFromNniPortNum(ctx, classifier[InPort].(uint32))
+		if err != nil {
+			logger.Debugw(ctx, "invalid-classifier-port-number",
+				log.Fields{
+					"port-number": action[Output].(uint32),
+					"error":       err})
+			return uint32(0), err
+		}
+		logger.Infow(ctx, "input-nni-intfId-is", log.Fields{"intf-id": intfID})
+		return intfID, nil
+	}
+	return uint32(0), nil
+}
+
+// UpdateGemPortForPktIn updates gemport for packet-in in to the cache and to the kv store as well.
+func (f *OpenOltFlowMgr) UpdateGemPortForPktIn(ctx context.Context, intfID uint32, onuID uint32, logicalPort uint32, gemPort uint32, pkt []byte) {
+	cTag, priority, err := getCTagFromPacket(ctx, pkt)
+	if err != nil {
+		logger.Errorw(ctx, "unable-to-update-gem-port-for-packet-in",
+			log.Fields{"intfID": intfID, "onuID": onuID, "logicalPort": logicalPort, "gemPort": gemPort, "err": err})
+		return
+	}
+	pktInkey := rsrcMgr.PacketInInfoKey{IntfID: intfID, OnuID: onuID, LogicalPort: logicalPort, VlanID: cTag, Priority: priority}
+
+	f.onuGemInfoLock.Lock()
+	defer f.onuGemInfoLock.Unlock()
+
+	lookupGemPort, ok := f.packetInGemPort[pktInkey]
+	if ok {
+		if lookupGemPort == gemPort {
+			logger.Infow(ctx, "pktin-key/value-found-in-cache--no-need-to-update-kv--assume-both-in-sync",
+				log.Fields{
+					"pktinkey": pktInkey,
+					"gem":      gemPort})
+			return
+		}
+	}
+	f.packetInGemPort[pktInkey] = gemPort
+
+	f.resourceMgr.UpdateGemPortForPktIn(ctx, pktInkey, gemPort)
+	logger.Infow(ctx, "pktin-key-not-found-in-local-cache-value-is-different--updating-cache-and-kv-store",
+		log.Fields{
+			"pktinkey": pktInkey,
+			"gem":      gemPort})
+}
+
+//getCTagFromPacket retrieves and returns c-tag and priority value from a packet.
+func getCTagFromPacket(ctx context.Context, packet []byte) (uint16, uint8, error) {
+	if packet == nil || len(packet) < 18 {
+		logger.Error(ctx, "unable-get-c-tag-from-the-packet--invalid-packet-length ")
+		return 0, 0, errors.New("invalid packet length")
+	}
+	outerEthType := (uint16(packet[12]) << 8) | uint16(packet[13])
+	innerEthType := (uint16(packet[16]) << 8) | uint16(packet[17])
+
+	var index int8
+	if outerEthType == 0x8100 {
+		if innerEthType == 0x8100 {
+			// q-in-q 802.1ad or 802.1q double tagged packet.
+			// get the inner vlanId
+			index = 18
+		} else {
+			index = 14
+		}
+		priority := (packet[index] >> 5) & 0x7
+		//13 bits composes vlanId value
+		vlan := ((uint16(packet[index]) << 8) & 0x0fff) | uint16(packet[index+1])
+		return vlan, priority, nil
+	}
+	logger.Debugf(ctx, "No vlanId found in the packet. Returning zero as c-tag")
+	return 0, 0, nil
+}
+
+// AddUniPortToOnuInfo adds uni port to the onugem info both in cache and kvstore.
+func (f *OpenOltFlowMgr) AddUniPortToOnuInfo(ctx context.Context, intfID uint32, onuID uint32, portNum uint32) {
+
+	f.onuGemInfoLock.Lock()
+	defer f.onuGemInfoLock.Unlock()
+
+	onugem := f.onuGemInfo[intfID]
+	for idx, onu := range onugem {
+		if onu.OnuID == onuID {
+			for _, uni := range onu.UniPorts {
+				if uni == portNum {
+					logger.Infow(ctx, "uni-already-in-cache--no-need-to-update-cache-and-kv-store", log.Fields{"uni": portNum})
+					return
+				}
+			}
+			onugem[idx].UniPorts = append(onugem[idx].UniPorts, portNum)
+			f.onuGemInfo[intfID] = onugem
+		}
+	}
+	f.resourceMgr.AddUniPortToOnuInfo(ctx, intfID, onuID, portNum)
+
+}
+
+func (f *OpenOltFlowMgr) loadFlowIDlistForGem(ctx context.Context, intf uint32) {
+	flowIDsList, err := f.resourceMgr.GetFlowIDsGemMapForInterface(ctx, intf)
+	if err != nil {
+		logger.Error(ctx, "failed-to-get-flowid-list-per-gem", log.Fields{"intf": intf})
+		return
+	}
+	for gem, FlowIDs := range flowIDsList {
+		gemPK := gemPortKey{intf, uint32(gem)}
+		if f.perGemPortLock.TryLock(gemPK) {
+			f.flowsUsedByGemPort[gemPK] = FlowIDs
+			f.perGemPortLock.Unlock(gemPK)
+		} else {
+			logger.Error(ctx, "failed-to-acquire-per-gem-port-lock",
+				log.Fields{
+					"intf-id":   intf,
+					"device-id": f.deviceHandler.device.Id,
+					"key":       gemPK,
+				})
+		}
+	}
+}
+
+//loadInterfaceToMulticastQueueMap reads multicast queues per interface from the KV store
+//and put them into interfaceToMcastQueueMap.
+func (f *OpenOltFlowMgr) loadInterfaceToMulticastQueueMap(ctx context.Context) {
+	storedMulticastQueueMap, err := f.resourceMgr.GetMcastQueuePerInterfaceMap(ctx)
+	if err != nil {
+		logger.Error(ctx, "failed-to-get-pon-interface-to-multicast-queue-map")
+		return
+	}
+	for intf, queueInfo := range storedMulticastQueueMap {
+		q := queueInfoBrief{
+			gemPortID:       queueInfo[0],
+			servicePriority: queueInfo[1],
+		}
+		f.interfaceToMcastQueueMap[intf] = &q
+	}
+}
+
+//GetFlowGroupFromKVStore fetches and returns flow group from the KV store. Returns (nil, false, error) if any problem occurs during
+//fetching the data. Returns (group, true, nil) if the group is fetched and returned successfully.
+//Returns (nil, false, nil) if the group does not exists in the KV store.
+func (f *OpenOltFlowMgr) GetFlowGroupFromKVStore(ctx context.Context, groupID uint32, cached bool) (*ofp.OfpGroupEntry, bool, error) {
+	exists, groupInfo, err := f.resourceMgr.GetFlowGroupFromKVStore(ctx, groupID, cached)
+	if err != nil {
+		return nil, false, olterrors.NewErrNotFound("flow-group", log.Fields{"group-id": groupID}, err)
+	}
+	if exists {
+		return newGroup(groupInfo.GroupID, groupInfo.OutPorts), exists, nil
+	}
+	return nil, exists, nil
+}
+
+func newGroup(groupID uint32, outPorts []uint32) *ofp.OfpGroupEntry {
+	groupDesc := ofp.OfpGroupDesc{
+		Type:    ofp.OfpGroupType_OFPGT_ALL,
+		GroupId: groupID,
+	}
+	groupEntry := ofp.OfpGroupEntry{
+		Desc: &groupDesc,
+	}
+	for i := 0; i < len(outPorts); i++ {
+		var acts []*ofp.OfpAction
+		acts = append(acts, flows.Output(outPorts[i]))
+		bucket := ofp.OfpBucket{
+			Actions: acts,
+		}
+		groupDesc.Buckets = append(groupDesc.Buckets, &bucket)
+	}
+	return &groupEntry
+}
+
+// L2oamCreateSchedulerQueues creates scheduler queues
+func (f *OpenOltFlowMgr) L2oamCreateSchedulerQueues(ctx context.Context, sq schedQueue) error {
+	if !autoAddFlow {
+		return nil
+	}
+
+	var meterConfig *ofp.OfpMeterConfig
+	if sq.flowMetadata != nil {
+		for _, meter := range sq.flowMetadata.Meters {
+			if sq.meterID == meter.MeterId {
+				meterConfig = meter
+				logger.Debugw(ctx, "found-meter-config-from-flowmetadata",
+					log.Fields{"meterConfig": meterConfig,
+						"device-id": f.deviceHandler.device.Id})
+				break
+			}
+		}
+	} else {
+		logger.Errorw(ctx, "flow-metadata-not-present-in-flow", log.Fields{"device-id": f.deviceHandler.device.Id})
+	}
+	if meterConfig == nil {
+		return olterrors.NewErrNotFound("meterbands", log.Fields{
+			"reason":        "Could-not-get-meterbands-from-flowMetadata",
+			"flow-metadata": sq.flowMetadata,
+			"meter-id":      sq.meterID,
+			"device-id":     f.deviceHandler.device.Id}, nil)
+	} else if len(meterConfig.Bands) < MaxMeterBand {
+		logger.Errorw(ctx, "invalid-number-of-bands-in-meter",
+			log.Fields{"Bands": meterConfig.Bands,
+				"meter-id":  sq.meterID,
+				"device-id": f.deviceHandler.device.Id})
+		return olterrors.NewErrInvalidValue(log.Fields{
+			"reason":          "Invalid-number-of-bands-in-meter",
+			"meterband-count": len(meterConfig.Bands),
+			"metabands":       meterConfig.Bands,
+			"meter-id":        sq.meterID,
+			"device-id":       f.deviceHandler.device.Id}, nil)
+	}
+	cir := meterConfig.Bands[0].Rate
+	eir := meterConfig.Bands[1].Rate
+	pir := cir + eir
+	onuKey := f.deviceHandler.formOnuKey(sq.intfID, sq.onuID)
+	onuDev, ok := f.deviceHandler.onus.Load(onuKey)
+	if !ok {
+		logger.Errorw(ctx, "not-found-onu-device",
+			log.Fields{"intf-id": sq.intfID,
+				"onu-id": sq.onuID})
+	} else {
+		onuDeviceID := (onuDev.(*OnuDevice)).deviceID
+		if _, exists := mapCreateScheduler[onuDeviceID]; exists {
+			logger.Debugw(ctx, "scheduler-exists",
+				log.Fields{"onu-device-id": onuDeviceID})
+			return nil
+		}
+		mapCreateScheduler[onuDeviceID] = true
+		l2oamCmd := &L2oamCmd{
+			Type:        "add-flow",
+			Cir:         []byte{0x00, 0x00, 0x00, 0x00},
+			Pir:         []byte{0x00, 0x00, 0x00, 0x00},
+			OnuDeviceID: onuDeviceID,
+		}
+		binary.BigEndian.PutUint32(l2oamCmd.Cir[0:4], cir)
+		binary.BigEndian.PutUint32(l2oamCmd.Pir[0:4], pir)
+		L2oamAddFlow(ctx, f.deviceHandler, l2oamCmd)
+
+		f.deviceHandler.L2oamAddFlowAndMount(ctx, onuDeviceID, []byte{0x0f, 0xfb}, []byte{0x00, 0x64})
+	}
+
+	return nil
+}
+
+// l2oamAddEapolToDevice adds EAPOL flow to device
+/*
+func (f *OpenOltFlowMgr) l2oamAddEapolToDevice(ctx context.Context, intfID uint32, onuID uint32) error {
+	if !autoAddFlow {
+		return nil
+	}
+
+	onuKey := f.deviceHandler.formOnuKey(intfID, onuID)
+	onuDev, ok := f.deviceHandler.onus.Load(onuKey)
+	if !ok {
+		logger.Errorw(ctx, "not-found-onu-device",
+			log.Fields{"intf-id": intfID,
+				"onu-id": onuID})
+	} else {
+		f.deviceHandler.L2oamAddFlowAndMount(ctx, (onuDev.(*OnuDevice)).deviceID, []byte{0x0f, 0xfb}, []byte{0x00, 0x64})
+	}
+
+	return nil
+}
+*/
+
+func (f *OpenOltFlowMgr) l2oamAddFlowDevice(ctx context.Context, intfID uint32, onuID uint32, ovid uint32, ivid uint32) {
+	logger.Debugw(ctx, "add-flow-to-device",
+		log.Fields{"onu-id": onuID, "o-vid": ovid, "i-vid": ivid})
+
+	if !autoAddFlow {
+		return
+	}
+
+	onuKey := f.deviceHandler.formOnuKey(intfID, onuID)
+	onuDev, ok := f.deviceHandler.onus.Load(onuKey)
+	if !ok {
+		logger.Errorw(ctx, "not-found-onu-device",
+			log.Fields{"intf-id": intfID,
+				"onu-id": onuID})
+	} else {
+		onuDeviceID := (onuDev.(*OnuDevice)).deviceID
+		if _, exists := mapAddFlow[onuDeviceID]; exists {
+			logger.Debugw(ctx, "flow is added already",
+				log.Fields{"onu-device-id": onuDeviceID})
+			return
+		}
+		mapAddFlow[onuDeviceID] = true
+		ovidBytes := []byte{0x00, 0x00}
+		binary.BigEndian.PutUint16(ovidBytes[:], uint16(ovid))
+		ividBytes := []byte{0x00, 0x00}
+		binary.BigEndian.PutUint16(ividBytes[:], uint16(ivid))
+		f.deviceHandler.L2oamAddFlowAndMount(ctx, onuDeviceID, ovidBytes, ividBytes)
+	}
+}