diff --git a/rw_core/utils/core_utils.go b/rw_core/utils/core_utils.go
index cf77d59..813c978 100644
--- a/rw_core/utils/core_utils.go
+++ b/rw_core/utils/core_utils.go
@@ -59,12 +59,12 @@
 		if !ok { // closed channel
 			//Set the channel at that index to nil to disable this case, hence preventing it from interfering with other cases.
 			cases[index].Chan = reflect.ValueOf(nil)
-			errors[index] = status.Errorf(codes.Internal, "channel closed")
+			errors[index] = status.Error(codes.Internal, "channel closed")
 			errorsReceived = true
 		} else if index == len(chnls) { // Timeout has occurred
 			for k := range errors {
 				if !resultsReceived[k] {
-					errors[k] = status.Errorf(codes.Aborted, "timeout")
+					errors[k] = status.Error(codes.Aborted, "timeout")
 				}
 			}
 			errorsReceived = true
diff --git a/rw_core/utils/core_utils_test.go b/rw_core/utils/core_utils_test.go
new file mode 100644
index 0000000..cb0abfe
--- /dev/null
+++ b/rw_core/utils/core_utils_test.go
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2019-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 utils
+
+import (
+	"github.com/opencord/voltha-go/common/log"
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"math/rand"
+	"testing"
+	"time"
+)
+
+var (
+	timeoutError     error
+	taskFailureError error
+)
+
+func init() {
+	log.AddPackage(log.JSON, log.WarnLevel, nil)
+	timeoutError = status.Errorf(codes.Aborted, "timeout")
+	taskFailureError = status.Error(codes.Internal, "test failure task")
+}
+
+func runSuccessfulTask(ch chan interface{}, durationRange int) {
+	time.Sleep(time.Duration(rand.Intn(durationRange)) * time.Millisecond)
+	ch <- nil
+}
+
+func runFailureTask(ch chan interface{}, durationRange int) {
+	time.Sleep(time.Duration(rand.Intn(durationRange)) * time.Millisecond)
+	ch <- taskFailureError
+}
+
+func runMultipleTasks(timeout, numTasks, taskDurationRange, numSuccessfulTask, numFailuretask int) []error {
+	if numTasks != numSuccessfulTask+numFailuretask {
+		return []error{status.Error(codes.FailedPrecondition, "invalid-num-tasks")}
+	}
+	numSuccessfulTaskCreated := 0
+	chnls := make([]chan interface{}, numTasks)
+	for i := 0; i < numTasks; i++ {
+		chnls[i] = make(chan interface{})
+		if numSuccessfulTaskCreated < numSuccessfulTask {
+			go runSuccessfulTask(chnls[i], taskDurationRange)
+			numSuccessfulTaskCreated += 1
+			continue
+		}
+		go runFailureTask(chnls[i], taskDurationRange)
+	}
+	return WaitForNilOrErrorResponses(int64(timeout), chnls...)
+}
+
+func getNumSuccessFailure(inputs []error) (numSuccess, numFailure, numTimeout int) {
+	numFailure = 0
+	numSuccess = 0
+	numTimeout = 0
+	for _, input := range inputs {
+		if input != nil {
+			if input.Error() == timeoutError.Error() {
+				numTimeout += 1
+			}
+			numFailure += 1
+		} else {
+			numSuccess += 1
+		}
+	}
+	return
+}
+
+func TestNoTimeouts(t *testing.T) {
+	var (
+		totalSuccess int
+		totalFailure int
+		results      []error
+		nSuccess     int
+		nFailure     int
+		nTimeouts    int
+	)
+	numIterations := 5
+	numTasks := 5
+	for i := 0; i < numIterations; i++ {
+		totalSuccess = rand.Intn(numTasks)
+		totalFailure = numTasks - totalSuccess
+		results = runMultipleTasks(110, numTasks, 100, totalSuccess, totalFailure)
+		nSuccess, nFailure, nTimeouts = getNumSuccessFailure(results)
+		assert.Equal(t, totalFailure, nFailure)
+		assert.Equal(t, totalSuccess, nSuccess)
+		assert.Equal(t, 0, nTimeouts)
+
+	}
+}
+
+func TestSomeTasksTimeouts(t *testing.T) {
+	var (
+		totalSuccess int
+		totalFailure int
+		results      []error
+		nSuccess     int
+		nFailure     int
+		nTimeouts    int
+	)
+	numIterations := 5
+	numTasks := 5
+	for i := 0; i < numIterations; i++ {
+		totalSuccess = rand.Intn(numTasks)
+		totalFailure = numTasks - totalSuccess
+		results = runMultipleTasks(50, numTasks, 100, totalSuccess, totalFailure)
+		nSuccess, nFailure, nTimeouts = getNumSuccessFailure(results)
+		assert.True(t, nFailure >= totalFailure)
+		assert.True(t, nSuccess <= totalSuccess)
+		assert.True(t, nTimeouts > 0)
+	}
+}
diff --git a/rw_core/utils/flow_utils.go b/rw_core/utils/flow_utils.go
index c2c9287..c1ca18d 100644
--- a/rw_core/utils/flow_utils.go
+++ b/rw_core/utils/flow_utils.go
@@ -17,12 +17,746 @@
 
 import (
 	"bytes"
+	"crypto/md5"
+	"fmt"
 	"github.com/cevaris/ordered_map"
 	"github.com/gogo/protobuf/proto"
+	"github.com/opencord/voltha-go/common/log"
 	ofp "github.com/opencord/voltha-protos/go/openflow_13"
+	"math/big"
 	"strings"
 )
 
+var (
+	// Instructions shortcut
+	APPLY_ACTIONS = ofp.OfpInstructionType_OFPIT_APPLY_ACTIONS
+
+	//OFPAT_* shortcuts
+	OUTPUT       = ofp.OfpActionType_OFPAT_OUTPUT
+	COPY_TTL_OUT = ofp.OfpActionType_OFPAT_COPY_TTL_OUT
+	COPY_TTL_IN  = ofp.OfpActionType_OFPAT_COPY_TTL_IN
+	SET_MPLS_TTL = ofp.OfpActionType_OFPAT_SET_MPLS_TTL
+	DEC_MPLS_TTL = ofp.OfpActionType_OFPAT_DEC_MPLS_TTL
+	PUSH_VLAN    = ofp.OfpActionType_OFPAT_PUSH_VLAN
+	POP_VLAN     = ofp.OfpActionType_OFPAT_POP_VLAN
+	PUSH_MPLS    = ofp.OfpActionType_OFPAT_PUSH_MPLS
+	POP_MPLS     = ofp.OfpActionType_OFPAT_POP_MPLS
+	SET_QUEUE    = ofp.OfpActionType_OFPAT_SET_QUEUE
+	GROUP        = ofp.OfpActionType_OFPAT_GROUP
+	SET_NW_TTL   = ofp.OfpActionType_OFPAT_SET_NW_TTL
+	NW_TTL       = ofp.OfpActionType_OFPAT_DEC_NW_TTL
+	SET_FIELD    = ofp.OfpActionType_OFPAT_SET_FIELD
+	PUSH_PBB     = ofp.OfpActionType_OFPAT_PUSH_PBB
+	POP_PBB      = ofp.OfpActionType_OFPAT_POP_PBB
+	EXPERIMENTER = ofp.OfpActionType_OFPAT_EXPERIMENTER
+
+	//OFPXMT_OFB_* shortcuts (incomplete)
+	IN_PORT         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IN_PORT
+	IN_PHY_PORT     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IN_PHY_PORT
+	METADATA        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_METADATA
+	ETH_DST         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ETH_DST
+	ETH_SRC         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ETH_SRC
+	ETH_TYPE        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ETH_TYPE
+	VLAN_VID        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_VID
+	VLAN_PCP        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_VLAN_PCP
+	IP_DSCP         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IP_DSCP
+	IP_ECN          = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IP_ECN
+	IP_PROTO        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IP_PROTO
+	IPV4_SRC        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV4_SRC
+	IPV4_DST        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV4_DST
+	TCP_SRC         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_TCP_SRC
+	TCP_DST         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_TCP_DST
+	UDP_SRC         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_UDP_SRC
+	UDP_DST         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_UDP_DST
+	SCTP_SRC        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_SCTP_SRC
+	SCTP_DST        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_SCTP_DST
+	ICMPV4_TYPE     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ICMPV4_TYPE
+	ICMPV4_CODE     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ICMPV4_CODE
+	ARP_OP          = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ARP_OP
+	ARP_SPA         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ARP_SPA
+	ARP_TPA         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ARP_TPA
+	ARP_SHA         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ARP_SHA
+	ARP_THA         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ARP_THA
+	IPV6_SRC        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_SRC
+	IPV6_DST        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_DST
+	IPV6_FLABEL     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_FLABEL
+	ICMPV6_TYPE     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ICMPV6_TYPE
+	ICMPV6_CODE     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_ICMPV6_CODE
+	IPV6_ND_TARGET  = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_ND_TARGET
+	OFB_IPV6_ND_SLL = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_ND_SLL
+	IPV6_ND_TLL     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_ND_TLL
+	MPLS_LABEL      = ofp.OxmOfbFieldTypes_OFPXMT_OFB_MPLS_LABEL
+	MPLS_TC         = ofp.OxmOfbFieldTypes_OFPXMT_OFB_MPLS_TC
+	MPLS_BOS        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_MPLS_BOS
+	PBB_ISID        = ofp.OxmOfbFieldTypes_OFPXMT_OFB_PBB_ISID
+	TUNNEL_ID       = ofp.OxmOfbFieldTypes_OFPXMT_OFB_TUNNEL_ID
+	IPV6_EXTHDR     = ofp.OxmOfbFieldTypes_OFPXMT_OFB_IPV6_EXTHDR
+)
+
+//ofp_action_* shortcuts
+
+func Output(port uint32, maxLen ...ofp.OfpControllerMaxLen) *ofp.OfpAction {
+	maxLength := ofp.OfpControllerMaxLen_OFPCML_MAX
+	if len(maxLen) > 0 {
+		maxLength = maxLen[0]
+	}
+	return &ofp.OfpAction{Type: OUTPUT, Action: &ofp.OfpAction_Output{Output: &ofp.OfpActionOutput{Port: port, MaxLen: uint32(maxLength)}}}
+}
+
+func MplsTtl(ttl uint32) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: SET_MPLS_TTL, Action: &ofp.OfpAction_MplsTtl{MplsTtl: &ofp.OfpActionMplsTtl{MplsTtl: ttl}}}
+}
+
+func PushVlan(ethType uint32) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: PUSH_VLAN, Action: &ofp.OfpAction_Push{Push: &ofp.OfpActionPush{Ethertype: ethType}}}
+}
+
+func PopVlan() *ofp.OfpAction {
+	return &ofp.OfpAction{Type: POP_VLAN}
+}
+
+func PopMpls(ethType uint32) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: POP_MPLS, Action: &ofp.OfpAction_PopMpls{PopMpls: &ofp.OfpActionPopMpls{Ethertype: ethType}}}
+}
+
+func Group(groupId uint32) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: GROUP, Action: &ofp.OfpAction_Group{Group: &ofp.OfpActionGroup{GroupId: groupId}}}
+}
+
+func NwTtl(nwTtl uint32) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: NW_TTL, Action: &ofp.OfpAction_NwTtl{NwTtl: &ofp.OfpActionNwTtl{NwTtl: nwTtl}}}
+}
+
+func SetField(field *ofp.OfpOxmOfbField) *ofp.OfpAction {
+	actionSetField := &ofp.OfpOxmField{OxmClass: ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC, Field: &ofp.OfpOxmField_OfbField{OfbField: field}}
+	return &ofp.OfpAction{Type: SET_FIELD, Action: &ofp.OfpAction_SetField{SetField: &ofp.OfpActionSetField{Field: actionSetField}}}
+}
+
+func Experimenter(experimenter uint32, data []byte) *ofp.OfpAction {
+	return &ofp.OfpAction{Type: EXPERIMENTER, Action: &ofp.OfpAction_Experimenter{Experimenter: &ofp.OfpActionExperimenter{Experimenter: experimenter, Data: data}}}
+}
+
+//ofb_field generators (incomplete set)
+
+func InPort(inPort uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IN_PORT, Value: &ofp.OfpOxmOfbField_Port{Port: inPort}}
+}
+
+func InPhyPort(inPhyPort uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IN_PHY_PORT, Value: &ofp.OfpOxmOfbField_Port{Port: inPhyPort}}
+}
+
+func Metadata_ofp(tableMetadata uint64) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: METADATA, Value: &ofp.OfpOxmOfbField_TableMetadata{TableMetadata: tableMetadata}}
+}
+
+// should Metadata_ofp used here ?????
+func EthDst(ethDst uint64) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ETH_DST, Value: &ofp.OfpOxmOfbField_TableMetadata{TableMetadata: ethDst}}
+}
+
+// should Metadata_ofp used here ?????
+func EthSrc(ethSrc uint64) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ETH_SRC, Value: &ofp.OfpOxmOfbField_TableMetadata{TableMetadata: ethSrc}}
+}
+
+func EthType(ethType uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ETH_TYPE, Value: &ofp.OfpOxmOfbField_EthType{EthType: ethType}}
+}
+
+func VlanVid(vlanVid uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: VLAN_VID, Value: &ofp.OfpOxmOfbField_VlanVid{VlanVid: vlanVid}}
+}
+
+func VlanPcp(vlanPcp uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: VLAN_PCP, Value: &ofp.OfpOxmOfbField_VlanPcp{VlanPcp: vlanPcp}}
+}
+
+func IpDscp(ipDscp uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IP_DSCP, Value: &ofp.OfpOxmOfbField_IpDscp{IpDscp: ipDscp}}
+}
+
+func IpEcn(ipEcn uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IP_ECN, Value: &ofp.OfpOxmOfbField_IpEcn{IpEcn: ipEcn}}
+}
+
+func IpProto(ipProto uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IP_PROTO, Value: &ofp.OfpOxmOfbField_IpProto{IpProto: ipProto}}
+}
+
+func Ipv4Src(ipv4Src uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV4_SRC, Value: &ofp.OfpOxmOfbField_Ipv4Src{Ipv4Src: ipv4Src}}
+}
+
+func Ipv4Dst(ipv4Dst uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV4_DST, Value: &ofp.OfpOxmOfbField_Ipv4Dst{Ipv4Dst: ipv4Dst}}
+}
+
+func TcpSrc(tcpSrc uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: TCP_SRC, Value: &ofp.OfpOxmOfbField_TcpSrc{TcpSrc: tcpSrc}}
+}
+
+func TcpDst(tcpDst uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: TCP_DST, Value: &ofp.OfpOxmOfbField_TcpDst{TcpDst: tcpDst}}
+}
+
+func UdpSrc(udpSrc uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: UDP_SRC, Value: &ofp.OfpOxmOfbField_UdpSrc{UdpSrc: udpSrc}}
+}
+
+func UdpDst(udpDst uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: UDP_DST, Value: &ofp.OfpOxmOfbField_UdpDst{UdpDst: udpDst}}
+}
+
+func SctpSrc(sctpSrc uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: SCTP_SRC, Value: &ofp.OfpOxmOfbField_SctpSrc{SctpSrc: sctpSrc}}
+}
+
+func SctpDst(sctpDst uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: SCTP_DST, Value: &ofp.OfpOxmOfbField_SctpDst{SctpDst: sctpDst}}
+}
+
+func Icmpv4Type(icmpv4Type uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ICMPV4_TYPE, Value: &ofp.OfpOxmOfbField_Icmpv4Type{Icmpv4Type: icmpv4Type}}
+}
+
+func Icmpv4Code(icmpv4Code uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ICMPV4_CODE, Value: &ofp.OfpOxmOfbField_Icmpv4Code{Icmpv4Code: icmpv4Code}}
+}
+
+func ArpOp(arpOp uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ARP_OP, Value: &ofp.OfpOxmOfbField_ArpOp{ArpOp: arpOp}}
+}
+
+func ArpSpa(arpSpa uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ARP_SPA, Value: &ofp.OfpOxmOfbField_ArpSpa{ArpSpa: arpSpa}}
+}
+
+func ArpTpa(arpTpa uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ARP_TPA, Value: &ofp.OfpOxmOfbField_ArpTpa{ArpTpa: arpTpa}}
+}
+
+func ArpSha(arpSha []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ARP_SHA, Value: &ofp.OfpOxmOfbField_ArpSha{ArpSha: arpSha}}
+}
+
+func ArpTha(arpTha []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ARP_THA, Value: &ofp.OfpOxmOfbField_ArpTha{ArpTha: arpTha}}
+}
+
+func Ipv6Src(ipv6Src []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_SRC, Value: &ofp.OfpOxmOfbField_Ipv6Src{Ipv6Src: ipv6Src}}
+}
+
+func Ipv6Dst(ipv6Dst []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_DST, Value: &ofp.OfpOxmOfbField_Ipv6Dst{Ipv6Dst: ipv6Dst}}
+}
+
+func Ipv6Flabel(ipv6Flabel uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_FLABEL, Value: &ofp.OfpOxmOfbField_Ipv6Flabel{Ipv6Flabel: ipv6Flabel}}
+}
+
+func Icmpv6Type(icmpv6Type uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ICMPV6_TYPE, Value: &ofp.OfpOxmOfbField_Icmpv6Type{Icmpv6Type: icmpv6Type}}
+}
+
+func Icmpv6Code(icmpv6Code uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: ICMPV6_CODE, Value: &ofp.OfpOxmOfbField_Icmpv6Code{Icmpv6Code: icmpv6Code}}
+}
+
+func Ipv6NdTarget(ipv6NdTarget []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_ND_TARGET, Value: &ofp.OfpOxmOfbField_Ipv6NdTarget{Ipv6NdTarget: ipv6NdTarget}}
+}
+
+func OfbIpv6NdSll(ofbIpv6NdSll []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: OFB_IPV6_ND_SLL, Value: &ofp.OfpOxmOfbField_Ipv6NdSsl{Ipv6NdSsl: ofbIpv6NdSll}}
+}
+
+func Ipv6NdTll(ipv6NdTll []byte) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_ND_TLL, Value: &ofp.OfpOxmOfbField_Ipv6NdTll{Ipv6NdTll: ipv6NdTll}}
+}
+
+func MplsLabel(mplsLabel uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: MPLS_LABEL, Value: &ofp.OfpOxmOfbField_MplsLabel{MplsLabel: mplsLabel}}
+}
+
+func MplsTc(mplsTc uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: MPLS_TC, Value: &ofp.OfpOxmOfbField_MplsTc{MplsTc: mplsTc}}
+}
+
+func MplsBos(mplsBos uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: MPLS_BOS, Value: &ofp.OfpOxmOfbField_MplsBos{MplsBos: mplsBos}}
+}
+
+func PbbIsid(pbbIsid uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: PBB_ISID, Value: &ofp.OfpOxmOfbField_PbbIsid{PbbIsid: pbbIsid}}
+}
+
+func TunnelId(tunnelId uint64) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: TUNNEL_ID, Value: &ofp.OfpOxmOfbField_TunnelId{TunnelId: tunnelId}}
+}
+
+func Ipv6Exthdr(ipv6Exthdr uint32) *ofp.OfpOxmOfbField {
+	return &ofp.OfpOxmOfbField{Type: IPV6_EXTHDR, Value: &ofp.OfpOxmOfbField_Ipv6Exthdr{Ipv6Exthdr: ipv6Exthdr}}
+}
+
+//frequently used extractors
+
+func excludeAction(action *ofp.OfpAction, exclude ...ofp.OfpActionType) bool {
+	for _, actionToExclude := range exclude {
+		if action.Type == actionToExclude {
+			return true
+		}
+	}
+	return false
+}
+
+func GetActions(flow *ofp.OfpFlowStats, exclude ...ofp.OfpActionType) []*ofp.OfpAction {
+	if flow == nil {
+		return nil
+	}
+	for _, instruction := range flow.Instructions {
+		if instruction.Type == uint32(ofp.OfpInstructionType_OFPIT_APPLY_ACTIONS) {
+			instActions := instruction.GetActions()
+			if instActions == nil {
+				return nil
+			}
+			if len(exclude) == 0 {
+				return instActions.Actions
+			} else {
+				filteredAction := make([]*ofp.OfpAction, 0)
+				for _, action := range instActions.Actions {
+					if !excludeAction(action, exclude...) {
+						filteredAction = append(filteredAction, action)
+					}
+				}
+				return filteredAction
+			}
+		}
+	}
+	return nil
+}
+
+func UpdateOutputPortByActionType(flow *ofp.OfpFlowStats, actionType uint32, toPort uint32) *ofp.OfpFlowStats {
+	if flow == nil {
+		return nil
+	}
+	nFlow := (proto.Clone(flow)).(*ofp.OfpFlowStats)
+	nFlow.Instructions = nil
+	nInsts := make([]*ofp.OfpInstruction, 0)
+	for _, instruction := range flow.Instructions {
+		if instruction.Type == actionType {
+			instActions := instruction.GetActions()
+			if instActions == nil {
+				return nil
+			}
+			nActions := make([]*ofp.OfpAction, 0)
+			for _, action := range instActions.Actions {
+				if action.GetOutput() != nil {
+					nActions = append(nActions, Output(toPort))
+				} else {
+					nActions = append(nActions, action)
+				}
+			}
+			instructionAction := ofp.OfpInstruction_Actions{Actions: &ofp.OfpInstructionActions{Actions: nActions}}
+			nInsts = append(nInsts, &ofp.OfpInstruction{Type: uint32(APPLY_ACTIONS), Data: &instructionAction})
+		} else {
+			nInsts = append(nInsts, instruction)
+		}
+	}
+	nFlow.Instructions = nInsts
+	return nFlow
+}
+
+func excludeOxmOfbField(field *ofp.OfpOxmOfbField, exclude ...ofp.OxmOfbFieldTypes) bool {
+	for _, fieldToExclude := range exclude {
+		if field.Type == fieldToExclude {
+			return true
+		}
+	}
+	return false
+}
+
+func GetOfbFields(flow *ofp.OfpFlowStats, exclude ...ofp.OxmOfbFieldTypes) []*ofp.OfpOxmOfbField {
+	if flow == nil || flow.Match == nil || flow.Match.Type != ofp.OfpMatchType_OFPMT_OXM {
+		return nil
+	}
+	ofbFields := make([]*ofp.OfpOxmOfbField, 0)
+	for _, field := range flow.Match.OxmFields {
+		if field.OxmClass == ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC {
+			ofbFields = append(ofbFields, field.GetOfbField())
+		}
+	}
+	if len(exclude) == 0 {
+		return ofbFields
+	} else {
+		filteredFields := make([]*ofp.OfpOxmOfbField, 0)
+		for _, ofbField := range ofbFields {
+			if !excludeOxmOfbField(ofbField, exclude...) {
+				filteredFields = append(filteredFields, ofbField)
+			}
+		}
+		return filteredFields
+	}
+}
+
+func GetPacketOutPort(packet *ofp.OfpPacketOut) uint32 {
+	if packet == nil {
+		return 0
+	}
+	for _, action := range packet.GetActions() {
+		if action.Type == OUTPUT {
+			return action.GetOutput().Port
+		}
+	}
+	return 0
+}
+
+func GetOutPort(flow *ofp.OfpFlowStats) uint32 {
+	if flow == nil {
+		return 0
+	}
+	for _, action := range GetActions(flow) {
+		if action.Type == OUTPUT {
+			out := action.GetOutput()
+			if out == nil {
+				return 0
+			}
+			return out.GetPort()
+		}
+	}
+	return 0
+}
+
+func GetInPort(flow *ofp.OfpFlowStats) uint32 {
+	if flow == nil {
+		return 0
+	}
+	for _, field := range GetOfbFields(flow) {
+		if field.Type == IN_PORT {
+			return field.GetPort()
+		}
+	}
+	return 0
+}
+
+func GetGotoTableId(flow *ofp.OfpFlowStats) uint32 {
+	if flow == nil {
+		return 0
+	}
+	for _, instruction := range flow.Instructions {
+		if instruction.Type == uint32(ofp.OfpInstructionType_OFPIT_GOTO_TABLE) {
+			gotoTable := instruction.GetGotoTable()
+			if gotoTable == nil {
+				return 0
+			}
+			return gotoTable.GetTableId()
+		}
+	}
+	return 0
+}
+
+func GetTunnelId(flow *ofp.OfpFlowStats) uint64 {
+	if flow == nil {
+		return 0
+	}
+	for _, field := range GetOfbFields(flow) {
+		if field.Type == TUNNEL_ID {
+			return field.GetTunnelId()
+		}
+	}
+	return 0
+}
+
+//GetMetaData - legacy get method (only want lower 32 bits)
+func GetMetaData(flow *ofp.OfpFlowStats) uint32 {
+	if flow == nil {
+		return 0
+	}
+	for _, field := range GetOfbFields(flow) {
+		if field.Type == METADATA {
+			return uint32(field.GetTableMetadata() & 0xffffffff)
+		}
+	}
+	return 0
+}
+
+func GetMetaData64Bit(flow *ofp.OfpFlowStats) uint64 {
+	if flow == nil {
+		return 0
+	}
+	for _, field := range GetOfbFields(flow) {
+		if field.Type == METADATA {
+			return field.GetTableMetadata()
+		}
+	}
+	return 0
+}
+
+// GetPortNumberFromMetadata retrieves the port number from the Metadata_ofp. The port number (UNI on ONU) is in the
+// lower 32-bits of Metadata_ofp and the inner_tag is in the upper 32-bits. This is set in the ONOS OltPipeline as
+// a Metadata_ofp field
+func GetPortNumberFromMetadata(flow *ofp.OfpFlowStats) uint64 {
+	md := GetMetaData64Bit(flow)
+	if md == 0 {
+		return 0
+	}
+	if md <= 0xffffffff {
+		log.Debugw("onos-upgrade-suggested", log.Fields{"Metadata_ofp": md, "message": "Legacy MetaData detected form OltPipeline"})
+		return md
+	}
+	return md & 0xffffffff
+}
+
+//GetInnerTagFromMetaData retrieves the inner tag from the Metadata_ofp. The port number (UNI on ONU) is in the
+// lower 32-bits of Metadata_ofp and the inner_tag is in the upper 32-bits. This is set in the ONOS OltPipeline as
+//// a Metadata_ofp field
+func GetInnerTagFromMetaData(flow *ofp.OfpFlowStats) uint64 {
+	md := GetMetaData64Bit(flow)
+	if md == 0 {
+		return 0
+	}
+	if md <= 0xffffffff {
+		log.Debugw("onos-upgrade-suggested", log.Fields{"Metadata_ofp": md, "message": "Legacy MetaData detected form OltPipeline"})
+		return md
+	}
+	return (md >> 32) & 0xffffffff
+}
+
+// Extract the child device port from a flow that contains the parent device peer port.  Typically the UNI port of an
+// ONU child device.  Per TST agreement this will be the lower 32 bits of tunnel id reserving upper 32 bits for later
+// use
+func GetChildPortFromTunnelId(flow *ofp.OfpFlowStats) uint32 {
+	tid := GetTunnelId(flow)
+	if tid == 0 {
+		return 0
+	}
+	// Per TST agreement we are keeping any child port id (uni port id) in the lower 32 bits
+	return uint32(tid & 0xffffffff)
+}
+
+func HasNextTable(flow *ofp.OfpFlowStats) bool {
+	if flow == nil {
+		return false
+	}
+	return GetGotoTableId(flow) != 0
+}
+
+func GetGroup(flow *ofp.OfpFlowStats) uint32 {
+	if flow == nil {
+		return 0
+	}
+	for _, action := range GetActions(flow) {
+		if action.Type == GROUP {
+			grp := action.GetGroup()
+			if grp == nil {
+				return 0
+			}
+			return grp.GetGroupId()
+		}
+	}
+	return 0
+}
+
+func HasGroup(flow *ofp.OfpFlowStats) bool {
+	return GetGroup(flow) != 0
+}
+
+// GetNextTableId returns the next table ID if the "table_id" is present in the map, otherwise return nil
+func GetNextTableId(kw OfpFlowModArgs) *uint32 {
+	if val, exist := kw["table_id"]; exist {
+		ret := uint32(val)
+		return &ret
+	}
+	return nil
+}
+
+// Return unique 64-bit integer hash for flow covering the following attributes:
+// 'table_id', 'priority', 'flags', 'cookie', 'match', '_instruction_string'
+func HashFlowStats(flow *ofp.OfpFlowStats) uint64 {
+	if flow == nil { // Should never happen
+		return 0
+	}
+	// Create string with the instructions field first
+	var instructionString bytes.Buffer
+	for _, instruction := range flow.Instructions {
+		instructionString.WriteString(instruction.String())
+	}
+	var flowString = fmt.Sprintf("%d%d%d%d%s%s", flow.TableId, flow.Priority, flow.Flags, flow.Cookie, flow.Match.String(), instructionString.String())
+	h := md5.New()
+	h.Write([]byte(flowString))
+	hash := big.NewInt(0)
+	hash.SetBytes(h.Sum(nil))
+	return hash.Uint64()
+}
+
+// flowStatsEntryFromFlowModMessage maps an ofp_flow_mod message to an ofp_flow_stats message
+func FlowStatsEntryFromFlowModMessage(mod *ofp.OfpFlowMod) *ofp.OfpFlowStats {
+	flow := &ofp.OfpFlowStats{}
+	if mod == nil {
+		return flow
+	}
+	flow.TableId = mod.TableId
+	flow.Priority = mod.Priority
+	flow.IdleTimeout = mod.IdleTimeout
+	flow.HardTimeout = mod.HardTimeout
+	flow.Flags = mod.Flags
+	flow.Cookie = mod.Cookie
+	flow.Match = mod.Match
+	flow.Instructions = mod.Instructions
+	flow.Id = HashFlowStats(flow)
+	return flow
+}
+
+func GroupEntryFromGroupMod(mod *ofp.OfpGroupMod) *ofp.OfpGroupEntry {
+	group := &ofp.OfpGroupEntry{}
+	if mod == nil {
+		return group
+	}
+	group.Desc = &ofp.OfpGroupDesc{Type: mod.Type, GroupId: mod.GroupId, Buckets: mod.Buckets}
+	group.Stats = &ofp.OfpGroupStats{GroupId: mod.GroupId}
+	//TODO do we need to instantiate bucket bins?
+	return group
+}
+
+func MkOxmFields(matchFields []ofp.OfpOxmField) []*ofp.OfpOxmField {
+	oxmFields := make([]*ofp.OfpOxmField, 0)
+	for _, matchField := range matchFields {
+		oxmField := ofp.OfpOxmField{OxmClass: ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC, Field: matchField.Field}
+		oxmFields = append(oxmFields, &oxmField)
+	}
+	return oxmFields
+}
+
+func MkInstructionsFromActions(actions []*ofp.OfpAction) []*ofp.OfpInstruction {
+	instructions := make([]*ofp.OfpInstruction, 0)
+	instructionAction := ofp.OfpInstruction_Actions{Actions: &ofp.OfpInstructionActions{Actions: actions}}
+	instruction := ofp.OfpInstruction{Type: uint32(APPLY_ACTIONS), Data: &instructionAction}
+	instructions = append(instructions, &instruction)
+	return instructions
+}
+
+// Convenience function to generare ofp_flow_mod message with OXM BASIC match composed from the match_fields, and
+// single APPLY_ACTIONS instruction with a list if ofp_action objects.
+func MkSimpleFlowMod(matchFields []*ofp.OfpOxmField, actions []*ofp.OfpAction, command *ofp.OfpFlowModCommand, kw OfpFlowModArgs) *ofp.OfpFlowMod {
+
+	// Process actions instructions
+	instructions := make([]*ofp.OfpInstruction, 0)
+	instructionAction := ofp.OfpInstruction_Actions{Actions: &ofp.OfpInstructionActions{Actions: actions}}
+	instruction := ofp.OfpInstruction{Type: uint32(APPLY_ACTIONS), Data: &instructionAction}
+	instructions = append(instructions, &instruction)
+
+	// Process next table
+	if tableId := GetNextTableId(kw); tableId != nil {
+		var instGotoTable ofp.OfpInstruction_GotoTable
+		instGotoTable.GotoTable = &ofp.OfpInstructionGotoTable{TableId: *tableId}
+		inst := ofp.OfpInstruction{Type: uint32(ofp.OfpInstructionType_OFPIT_GOTO_TABLE), Data: &instGotoTable}
+		instructions = append(instructions, &inst)
+	}
+
+	// Process match fields
+	oxmFields := make([]*ofp.OfpOxmField, 0)
+	for _, matchField := range matchFields {
+		oxmField := ofp.OfpOxmField{OxmClass: ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC, Field: matchField.Field}
+		oxmFields = append(oxmFields, &oxmField)
+	}
+	var match ofp.OfpMatch
+	match.Type = ofp.OfpMatchType_OFPMT_OXM
+	match.OxmFields = oxmFields
+
+	// Create ofp_flow_message
+	msg := &ofp.OfpFlowMod{}
+	if command == nil {
+		msg.Command = ofp.OfpFlowModCommand_OFPFC_ADD
+	} else {
+		msg.Command = *command
+	}
+	msg.Instructions = instructions
+	msg.Match = &match
+
+	// Set the variadic argument values
+	msg = setVariadicModAttributes(msg, kw)
+
+	return msg
+}
+
+func MkMulticastGroupMod(groupId uint32, buckets []*ofp.OfpBucket, command *ofp.OfpGroupModCommand) *ofp.OfpGroupMod {
+	group := &ofp.OfpGroupMod{}
+	if command == nil {
+		group.Command = ofp.OfpGroupModCommand_OFPGC_ADD
+	} else {
+		group.Command = *command
+	}
+	group.Type = ofp.OfpGroupType_OFPGT_ALL
+	group.GroupId = groupId
+	group.Buckets = buckets
+	return group
+}
+
+//SetVariadicModAttributes sets only uint64 or uint32 fields of the ofp_flow_mod message
+func setVariadicModAttributes(mod *ofp.OfpFlowMod, args OfpFlowModArgs) *ofp.OfpFlowMod {
+	if args == nil {
+		return mod
+	}
+	for key, val := range args {
+		switch key {
+		case "cookie":
+			mod.Cookie = val
+		case "cookie_mask":
+			mod.CookieMask = val
+		case "table_id":
+			mod.TableId = uint32(val)
+		case "idle_timeout":
+			mod.IdleTimeout = uint32(val)
+		case "hard_timeout":
+			mod.HardTimeout = uint32(val)
+		case "priority":
+			mod.Priority = uint32(val)
+		case "buffer_id":
+			mod.BufferId = uint32(val)
+		case "out_port":
+			mod.OutPort = uint32(val)
+		case "out_group":
+			mod.OutGroup = uint32(val)
+		case "flags":
+			mod.Flags = uint32(val)
+		}
+	}
+	return mod
+}
+
+func MkPacketIn(port uint32, packet []byte) *ofp.OfpPacketIn {
+	packetIn := &ofp.OfpPacketIn{
+		Reason: ofp.OfpPacketInReason_OFPR_ACTION,
+		Match: &ofp.OfpMatch{
+			Type: ofp.OfpMatchType_OFPMT_OXM,
+			OxmFields: []*ofp.OfpOxmField{
+				{
+					OxmClass: ofp.OfpOxmClass_OFPXMC_OPENFLOW_BASIC,
+					Field: &ofp.OfpOxmField_OfbField{
+						OfbField: InPort(port)},
+				},
+			},
+		},
+		Data: packet,
+	}
+	return packetIn
+}
+
+// MkFlowStat is a helper method to build flows
+func MkFlowStat(fa *FlowArgs) *ofp.OfpFlowStats {
+	//Build the matchfields
+	matchFields := make([]*ofp.OfpOxmField, 0)
+	for _, val := range fa.MatchFields {
+		matchFields = append(matchFields, &ofp.OfpOxmField{Field: &ofp.OfpOxmField_OfbField{OfbField: val}})
+	}
+	return FlowStatsEntryFromFlowModMessage(MkSimpleFlowMod(matchFields, fa.Actions, fa.Command, fa.KV))
+}
+
+func MkGroupStat(ga *GroupArgs) *ofp.OfpGroupEntry {
+	return GroupEntryFromGroupMod(MkMulticastGroupMod(ga.GroupId, ga.Buckets, ga.Command))
+}
+
 type OfpFlowModArgs map[string]uint64
 
 type FlowArgs struct {
@@ -127,6 +861,10 @@
 }
 
 func (fg *FlowsAndGroups) AddFlow(flow *ofp.OfpFlowStats) {
+	if flow == nil {
+		return
+	}
+
 	if fg.Flows == nil {
 		fg.Flows = ordered_map.NewOrderedMap()
 	}
@@ -139,6 +877,23 @@
 	}
 }
 
+func (fg *FlowsAndGroups) AddGroup(group *ofp.OfpGroupEntry) {
+	if group == nil {
+		return
+	}
+
+	if fg.Flows == nil {
+		fg.Flows = ordered_map.NewOrderedMap()
+	}
+	if fg.Groups == nil {
+		fg.Groups = ordered_map.NewOrderedMap()
+	}
+	//Add group only if absent
+	if _, exist := fg.Groups.Get(group.Desc.GroupId); !exist {
+		fg.Groups.Set(group.Desc.GroupId, group)
+	}
+}
+
 //AddFrom add flows and groups from the argument into this structure only if they do not already exist
 func (fg *FlowsAndGroups) AddFrom(from *FlowsAndGroups) {
 	iter := from.Flows.IterFunc()
@@ -266,6 +1021,9 @@
 //FlowMatch returns true if two flows matches on the following flow attributes:
 //TableId, Priority, Flags, Cookie, Match
 func FlowMatch(f1 *ofp.OfpFlowStats, f2 *ofp.OfpFlowStats) bool {
+	if f1 == nil || f2 == nil {
+		return false
+	}
 	keysMatter := []string{"TableId", "Priority", "Flags", "Cookie", "Match"}
 	for _, key := range keysMatter {
 		switch key {
@@ -297,6 +1055,9 @@
 //FlowMatchesMod returns True if given flow is "covered" by the wildcard flow_mod, taking into consideration of
 //both exact matches as well as masks-based match fields if any. Otherwise return False
 func FlowMatchesMod(flow *ofp.OfpFlowStats, mod *ofp.OfpFlowMod) bool {
+	if flow == nil || mod == nil {
+		return false
+	}
 	//Check if flow.cookie is covered by mod.cookie and mod.cookie_mask
 	if (flow.Cookie & mod.CookieMask) != (mod.Cookie & mod.CookieMask) {
 		return false
@@ -331,6 +1092,9 @@
 
 //FlowHasOutPort returns True if flow has a output command with the given out_port
 func FlowHasOutPort(flow *ofp.OfpFlowStats, outPort uint32) bool {
+	if flow == nil {
+		return false
+	}
 	for _, instruction := range flow.Instructions {
 		if instruction.Type == uint32(ofp.OfpInstructionType_OFPIT_APPLY_ACTIONS) {
 			if instruction.GetActions() == nil {
@@ -351,6 +1115,9 @@
 
 //FlowHasOutGroup return True if flow has a output command with the given out_group
 func FlowHasOutGroup(flow *ofp.OfpFlowStats, groupID uint32) bool {
+	if flow == nil {
+		return false
+	}
 	for _, instruction := range flow.Instructions {
 		if instruction.Type == uint32(ofp.OfpInstructionType_OFPIT_APPLY_ACTIONS) {
 			if instruction.GetActions() == nil {
diff --git a/rw_core/utils/flow_utils_test.go b/rw_core/utils/flow_utils_test.go
new file mode 100644
index 0000000..48a1b75
--- /dev/null
+++ b/rw_core/utils/flow_utils_test.go
@@ -0,0 +1,464 @@
+/*
+ * Copyright 2019-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 utils
+
+import (
+	"github.com/opencord/voltha-go/common/log"
+	ofp "github.com/opencord/voltha-protos/go/openflow_13"
+	"github.com/stretchr/testify/assert"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"strings"
+	"testing"
+)
+
+func init() {
+	log.AddPackage(log.JSON, log.WarnLevel, nil)
+	timeoutError = status.Errorf(codes.Aborted, "timeout")
+	taskFailureError = status.Error(codes.Internal, "test failure task")
+}
+
+func TestFlowsAndGroups_AddFlow(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	allFlows := fg.ListFlows()
+	assert.Equal(t, 0, len(allFlows))
+	fg.AddFlow(nil)
+	allFlows = fg.ListFlows()
+	assert.Equal(t, 0, len(allFlows))
+
+	var fa *FlowArgs
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(1),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 1),
+			TunnelId(uint64(1)),
+			EthType(0x0800),
+			Ipv4Dst(0xffffffff),
+			IpProto(17),
+			UdpSrc(68),
+			UdpDst(67),
+		},
+		Actions: []*ofp.OfpAction{
+			PushVlan(0x8100),
+			SetField(VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 4000)),
+			Output(uint32(ofp.OfpPortNo_OFPP_CONTROLLER)),
+		},
+	}
+	flow := MkFlowStat(fa)
+	fg.AddFlow(flow)
+
+	allFlows = fg.ListFlows()
+	assert.Equal(t, 1, len(allFlows))
+	assert.True(t, FlowMatch(flow, allFlows[0]))
+}
+
+func TestFlowsAndGroups_AddGroup(t *testing.T) {
+	var ga *GroupArgs
+
+	fg := NewFlowsAndGroups()
+	allGroups := fg.ListGroups()
+	assert.Equal(t, 0, len(allGroups))
+	fg.AddGroup(nil)
+	allGroups = fg.ListGroups()
+	assert.Equal(t, 0, len(allGroups))
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	allGroups = fg.ListGroups()
+	assert.Equal(t, 1, len(allGroups))
+	assert.Equal(t, ga.GroupId, allGroups[0].Desc.GroupId)
+}
+
+func TestFlowsAndGroups_Copy(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	var fa *FlowArgs
+	var ga *GroupArgs
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+		},
+		Actions: []*ofp.OfpAction{
+			SetField(VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 10)),
+			Output(1),
+		},
+	}
+	flow := MkFlowStat(fa)
+	fg.AddFlow(flow)
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	fgCopy := fg.Copy()
+
+	allFlows := fgCopy.ListFlows()
+	assert.Equal(t, 1, len(allFlows))
+	assert.True(t, FlowMatch(flow, allFlows[0]))
+
+	allGroups := fgCopy.ListGroups()
+	assert.Equal(t, 1, len(allGroups))
+	assert.Equal(t, ga.GroupId, allGroups[0].Desc.GroupId)
+
+	fg = NewFlowsAndGroups()
+	fgCopy = fg.Copy()
+	allFlows = fgCopy.ListFlows()
+	allGroups = fgCopy.ListGroups()
+	assert.Equal(t, 0, len(allFlows))
+	assert.Equal(t, 0, len(allGroups))
+}
+
+func TestFlowsAndGroups_GetFlow(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	var fa1 *FlowArgs
+	var fa2 *FlowArgs
+	var ga *GroupArgs
+
+	fa1 = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			Metadata_ofp((1000 << 32) | 1),
+			VlanPcp(0),
+		},
+		Actions: []*ofp.OfpAction{
+			PopVlan(),
+		},
+	}
+	flow1 := MkFlowStat(fa1)
+
+	fa2 = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 1500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(5),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+		},
+		Actions: []*ofp.OfpAction{
+			PushVlan(0x8100),
+			SetField(VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 1000)),
+			SetField(VlanPcp(0)),
+			Output(2),
+		},
+	}
+	flow2 := MkFlowStat(fa2)
+
+	fg.AddFlow(flow1)
+	fg.AddFlow(flow2)
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	gf1 := fg.GetFlow(0)
+	assert.True(t, FlowMatch(flow1, gf1))
+
+	gf2 := fg.GetFlow(1)
+	assert.True(t, FlowMatch(flow2, gf2))
+
+	gf3 := fg.GetFlow(2)
+	assert.Nil(t, gf3)
+
+	allFlows := fg.ListFlows()
+	assert.True(t, FlowMatch(flow1, allFlows[0]))
+	assert.True(t, FlowMatch(flow2, allFlows[1]))
+}
+
+func TestFlowsAndGroups_String(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	var fa *FlowArgs
+	var ga *GroupArgs
+
+	str := fg.String()
+	assert.True(t, str == "")
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			VlanPcp(0),
+			EthType(0x800),
+			Ipv4Dst(0xe00a0a0a),
+		},
+		Actions: []*ofp.OfpAction{
+			Group(10),
+		},
+	}
+	flow := MkFlowStat(fa)
+	fg.AddFlow(flow)
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	str = fg.String()
+	assert.True(t, strings.Contains(str, "id: 1143307409938767207"))
+	assert.True(t, strings.Contains(str, "group_id: 10"))
+	assert.True(t, strings.Contains(str, "oxm_class: OFPXMC_OPENFLOW_BASICOFPXMC_OPENFLOW_BASIC"))
+	assert.True(t, strings.Contains(str, "type: OFPXMT_OFB_VLAN_VIDOFPXMT_OFB_VLAN_VID"))
+	assert.True(t, strings.Contains(str, "vlan_vid: 4096"))
+	assert.True(t, strings.Contains(str, "buckets:"))
+}
+
+func TestFlowsAndGroups_AddFrom(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	var fa *FlowArgs
+	var ga *GroupArgs
+
+	str := fg.String()
+	assert.True(t, str == "")
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			Metadata_ofp(1000),
+			TunnelId(uint64(1)),
+			VlanPcp(0),
+		},
+		Actions: []*ofp.OfpAction{
+			PopVlan(),
+			Output(1),
+		},
+	}
+	flow := MkFlowStat(fa)
+	fg.AddFlow(flow)
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	fg1 := NewFlowsAndGroups()
+	fg1.AddFrom(fg)
+
+	allFlows := fg1.ListFlows()
+	allGroups := fg1.ListGroups()
+	assert.Equal(t, 1, len(allFlows))
+	assert.Equal(t, 1, len(allGroups))
+	assert.True(t, FlowMatch(flow, allFlows[0]))
+	assert.Equal(t, group.Desc.GroupId, allGroups[0].Desc.GroupId)
+}
+
+func TestDeviceRules_AddFlow(t *testing.T) {
+	dr := NewDeviceRules()
+	rules := dr.GetRules()
+	assert.True(t, len(rules) == 0)
+
+	dr.AddFlow("123456", nil)
+	rules = dr.GetRules()
+	assert.True(t, len(rules) == 1)
+	val, ok := rules["123456"]
+	assert.True(t, ok)
+	assert.Equal(t, 0, len(val.ListFlows()))
+	assert.Equal(t, 0, len(val.ListGroups()))
+
+	var fa *FlowArgs
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			Metadata_ofp(1000),
+			TunnelId(uint64(1)),
+			VlanPcp(0),
+		},
+		Actions: []*ofp.OfpAction{
+			PopVlan(),
+			Output(1),
+		},
+	}
+	flow := MkFlowStat(fa)
+	dr.AddFlow("123456", flow)
+	rules = dr.GetRules()
+	assert.True(t, len(rules) == 1)
+	val, ok = rules["123456"]
+	assert.True(t, ok)
+	assert.Equal(t, 1, len(val.ListFlows()))
+	assert.True(t, FlowMatch(flow, val.ListFlows()[0]))
+	assert.Equal(t, 0, len(val.ListGroups()))
+}
+
+func TestDeviceRules_AddFlowsAndGroup(t *testing.T) {
+	fg := NewFlowsAndGroups()
+	var fa *FlowArgs
+	var ga *GroupArgs
+
+	str := fg.String()
+	assert.True(t, str == "")
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 2000},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			Metadata_ofp(1000),
+			TunnelId(uint64(1)),
+			VlanPcp(0),
+		},
+		Actions: []*ofp.OfpAction{
+			PopVlan(),
+			Output(1),
+		},
+	}
+	flow := MkFlowStat(fa)
+	fg.AddFlow(flow)
+
+	ga = &GroupArgs{
+		GroupId: 10,
+		Buckets: []*ofp.OfpBucket{
+			{Actions: []*ofp.OfpAction{
+				PopVlan(),
+				Output(1),
+			},
+			},
+		},
+	}
+	group := MkGroupStat(ga)
+	fg.AddGroup(group)
+
+	dr := NewDeviceRules()
+	dr.AddFlowsAndGroup("123456", fg)
+	rules := dr.GetRules()
+	assert.True(t, len(rules) == 1)
+	val, ok := rules["123456"]
+	assert.True(t, ok)
+	assert.Equal(t, 1, len(val.ListFlows()))
+	assert.Equal(t, 1, len(val.ListGroups()))
+	assert.True(t, FlowMatch(flow, val.ListFlows()[0]))
+	assert.Equal(t, 10, int(val.ListGroups()[0].Desc.GroupId))
+}
+
+func TestFlowHasOutPort(t *testing.T) {
+	var flow *ofp.OfpFlowStats
+	assert.False(t, FlowHasOutPort(flow, 1))
+
+	fa := &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 2000},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			Metadata_ofp(1000),
+			TunnelId(uint64(1)),
+			VlanPcp(0),
+		},
+		Actions: []*ofp.OfpAction{
+			PopVlan(),
+			Output(1),
+		},
+	}
+	flow = MkFlowStat(fa)
+	assert.True(t, FlowHasOutPort(flow, 1))
+	assert.False(t, FlowHasOutPort(flow, 2))
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 2000},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+		},
+	}
+	flow = MkFlowStat(fa)
+	assert.False(t, FlowHasOutPort(flow, 1))
+}
+
+func TestFlowHasOutGroup(t *testing.T) {
+	var flow *ofp.OfpFlowStats
+	assert.False(t, FlowHasOutGroup(flow, 10))
+
+	fa := &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			VlanPcp(0),
+			EthType(0x800),
+			Ipv4Dst(0xe00a0a0a),
+		},
+		Actions: []*ofp.OfpAction{
+			Group(10),
+		},
+	}
+	flow = MkFlowStat(fa)
+	assert.True(t, FlowHasOutGroup(flow, 10))
+	assert.False(t, FlowHasOutGroup(flow, 11))
+
+	fa = &FlowArgs{
+		KV: OfpFlowModArgs{"priority": 500},
+		MatchFields: []*ofp.OfpOxmOfbField{
+			InPort(2),
+			VlanVid(uint32(ofp.OfpVlanId_OFPVID_PRESENT) | 0),
+			VlanPcp(0),
+			EthType(0x800),
+			Ipv4Dst(0xe00a0a0a),
+		},
+		Actions: []*ofp.OfpAction{
+			Output(1),
+		},
+	}
+	flow = MkFlowStat(fa)
+	assert.False(t, FlowHasOutGroup(flow, 1))
+}