diff --git a/internal/pkg/core/openolt.go b/internal/pkg/core/openolt.go
new file mode 100644
index 0000000..9a5167f
--- /dev/null
+++ b/internal/pkg/core/openolt.go
@@ -0,0 +1,388 @@
+/*
+ * Copyright 2018-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"
+	"sync"
+	"time"
+
+	"github.com/opencord/voltha-lib-go/v3/pkg/adapters/adapterif"
+	"github.com/opencord/voltha-lib-go/v3/pkg/kafka"
+	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	"github.com/opencord/voltha-openolt-adapter/internal/pkg/config"
+	ic "github.com/opencord/voltha-protos/v3/go/inter_container"
+	"github.com/opencord/voltha-protos/v3/go/openflow_13"
+	"github.com/opencord/voltha-protos/v3/go/voltha"
+)
+
+//OpenOLT structure holds the OLT information
+type OpenOLT struct {
+	deviceHandlers              map[string]*DeviceHandler
+	coreProxy                   adapterif.CoreProxy
+	adapterProxy                adapterif.AdapterProxy
+	eventProxy                  adapterif.EventProxy
+	kafkaICProxy                kafka.InterContainerProxy
+	config                      *config.AdapterFlags
+	numOnus                     int
+	KVStoreHost                 string
+	KVStorePort                 int
+	KVStoreType                 string
+	exitChannel                 chan int
+	HeartbeatCheckInterval      time.Duration
+	HeartbeatFailReportInterval time.Duration
+	GrpcTimeoutInterval         time.Duration
+	lockDeviceHandlersMap       sync.RWMutex
+}
+
+//NewOpenOLT returns a new instance of OpenOLT
+func NewOpenOLT(ctx context.Context, kafkaICProxy kafka.InterContainerProxy,
+	coreProxy adapterif.CoreProxy, adapterProxy adapterif.AdapterProxy,
+	eventProxy adapterif.EventProxy, cfg *config.AdapterFlags) *OpenOLT {
+	var openOLT OpenOLT
+	openOLT.exitChannel = make(chan int, 1)
+	openOLT.deviceHandlers = make(map[string]*DeviceHandler)
+	openOLT.kafkaICProxy = kafkaICProxy
+	openOLT.config = cfg
+	openOLT.numOnus = cfg.OnuNumber
+	openOLT.coreProxy = coreProxy
+	openOLT.adapterProxy = adapterProxy
+	openOLT.eventProxy = eventProxy
+	openOLT.KVStoreHost = cfg.KVStoreHost
+	openOLT.KVStorePort = cfg.KVStorePort
+	openOLT.KVStoreType = cfg.KVStoreType
+	openOLT.HeartbeatCheckInterval = cfg.HeartbeatCheckInterval
+	openOLT.HeartbeatFailReportInterval = cfg.HeartbeatFailReportInterval
+	openOLT.GrpcTimeoutInterval = cfg.GrpcTimeoutInterval
+	openOLT.lockDeviceHandlersMap = sync.RWMutex{}
+	return &openOLT
+}
+
+//Start starts (logs) the device manager
+func (oo *OpenOLT) Start(ctx context.Context) error {
+	log.Info("starting-device-manager")
+	log.Info("device-manager-started")
+	return nil
+}
+
+//Stop terminates the session
+func (oo *OpenOLT) Stop(ctx context.Context) error {
+	log.Info("stopping-device-manager")
+	oo.exitChannel <- 1
+	log.Info("device-manager-stopped")
+	return nil
+}
+
+func sendResponse(ctx context.Context, ch chan interface{}, result interface{}) {
+	if ctx.Err() == nil {
+		// Returned response only of the ctx has not been canceled/timeout/etc
+		// Channel is automatically closed when a context is Done
+		ch <- result
+		log.Debugw("sendResponse", log.Fields{"result": result})
+	} else {
+		// Should the transaction be reverted back?
+		log.Debugw("sendResponse-context-error", log.Fields{"context-error": ctx.Err()})
+	}
+}
+
+func (oo *OpenOLT) addDeviceHandlerToMap(agent *DeviceHandler) {
+	oo.lockDeviceHandlersMap.Lock()
+	defer oo.lockDeviceHandlersMap.Unlock()
+	if _, exist := oo.deviceHandlers[agent.deviceID]; !exist {
+		oo.deviceHandlers[agent.deviceID] = agent
+	}
+}
+
+func (oo *OpenOLT) deleteDeviceHandlerToMap(agent *DeviceHandler) {
+	oo.lockDeviceHandlersMap.Lock()
+	defer oo.lockDeviceHandlersMap.Unlock()
+	delete(oo.deviceHandlers, agent.deviceID)
+}
+
+func (oo *OpenOLT) getDeviceHandler(deviceID string) *DeviceHandler {
+	oo.lockDeviceHandlersMap.Lock()
+	defer oo.lockDeviceHandlersMap.Unlock()
+	if agent, ok := oo.deviceHandlers[deviceID]; ok {
+		return agent
+	}
+	return nil
+}
+
+//createDeviceTopic returns
+func (oo *OpenOLT) createDeviceTopic(device *voltha.Device) error {
+	log.Infow("create-device-topic", log.Fields{"deviceId": device.Id})
+	defaultTopic := oo.kafkaICProxy.GetDefaultTopic()
+	deviceTopic := kafka.Topic{Name: defaultTopic.Name + "_" + device.Id}
+	// TODO for the offset
+	if err := oo.kafkaICProxy.SubscribeWithDefaultRequestHandler(deviceTopic, 0); err != nil {
+		log.Infow("create-device-topic-failed", log.Fields{"deviceId": device.Id, "error": err})
+		return err
+	}
+	return nil
+}
+
+// Adopt_device creates a new device handler if not present already and then adopts the device
+func (oo *OpenOLT) Adopt_device(device *voltha.Device) error {
+	ctx := context.Background()
+	if device == nil {
+		return NewErrInvalidValue(log.Fields{"device": nil}, nil).Log()
+	}
+	log.Infow("adopt-device", log.Fields{"deviceId": device.Id})
+	var handler *DeviceHandler
+	if handler = oo.getDeviceHandler(device.Id); handler == nil {
+		handler := NewDeviceHandler(oo.coreProxy, oo.adapterProxy, oo.eventProxy, device, oo)
+		oo.addDeviceHandlerToMap(handler)
+		go handler.AdoptDevice(ctx, device)
+		// Launch the creation of the device topic
+		// go oo.createDeviceTopic(device)
+	}
+	return nil
+}
+
+//Get_ofp_device_info returns OFP information for the given device
+func (oo *OpenOLT) Get_ofp_device_info(device *voltha.Device) (*ic.SwitchCapability, error) {
+	log.Infow("Get_ofp_device_info", log.Fields{"deviceId": device.Id})
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.GetOfpDeviceInfo(device)
+	}
+	return nil, NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Get_ofp_port_info returns OFP port information for the given device
+func (oo *OpenOLT) Get_ofp_port_info(device *voltha.Device, portNo int64) (*ic.PortCapability, error) {
+	log.Infow("Get_ofp_port_info", log.Fields{"deviceId": device.Id})
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.GetOfpPortInfo(device, portNo)
+	}
+	return nil, NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Process_inter_adapter_message sends messages to a target device (between adapters)
+func (oo *OpenOLT) Process_inter_adapter_message(msg *ic.InterAdapterMessage) error {
+	log.Infow("Process_inter_adapter_message", log.Fields{"msgId": msg.Header.Id})
+	targetDevice := msg.Header.ProxyDeviceId // Request?
+	if targetDevice == "" && msg.Header.ToDeviceId != "" {
+		// Typical response
+		targetDevice = msg.Header.ToDeviceId
+	}
+	if handler := oo.getDeviceHandler(targetDevice); handler != nil {
+		return handler.ProcessInterAdapterMessage(msg)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": targetDevice}, nil).Log()
+}
+
+//Adapter_descriptor not implemented
+func (oo *OpenOLT) Adapter_descriptor() error {
+	return ErrNotImplemented
+}
+
+//Device_types unimplemented
+func (oo *OpenOLT) Device_types() (*voltha.DeviceTypes, error) {
+	return nil, ErrNotImplemented
+}
+
+//Health  returns unimplemented
+func (oo *OpenOLT) Health() (*voltha.HealthStatus, error) {
+	return nil, ErrNotImplemented
+}
+
+//Reconcile_device unimplemented
+func (oo *OpenOLT) Reconcile_device(device *voltha.Device) error {
+	ctx := context.Background()
+	if device == nil {
+		return NewErrInvalidValue(log.Fields{"device": nil}, nil).Log()
+	}
+	log.Infow("reconcile-device", log.Fields{"deviceId": device.Id})
+	var handler *DeviceHandler
+	if handler = oo.getDeviceHandler(device.Id); handler == nil {
+		handler := NewDeviceHandler(oo.coreProxy, oo.adapterProxy, oo.eventProxy, device, oo)
+		oo.addDeviceHandlerToMap(handler)
+		handler.transitionMap = NewTransitionMap(handler)
+		handler.transitionMap.Handle(ctx, DeviceInit)
+	}
+	return nil
+}
+
+//Abandon_device unimplemented
+func (oo *OpenOLT) Abandon_device(device *voltha.Device) error {
+	return ErrNotImplemented
+}
+
+//Disable_device disables the given device
+func (oo *OpenOLT) Disable_device(device *voltha.Device) error {
+	log.Infow("disable-device", log.Fields{"deviceId": device.Id})
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.DisableDevice(device)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Reenable_device enables the olt device after disable
+func (oo *OpenOLT) Reenable_device(device *voltha.Device) error {
+	log.Infow("reenable-device", log.Fields{"deviceId": device.Id})
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.ReenableDevice(device)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Reboot_device reboots the given device
+func (oo *OpenOLT) Reboot_device(device *voltha.Device) error {
+	log.Infow("reboot-device", log.Fields{"deviceId": device.Id})
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.RebootDevice(device)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Self_test_device unimplented
+func (oo *OpenOLT) Self_test_device(device *voltha.Device) error {
+	return ErrNotImplemented
+}
+
+//Delete_device unimplemented
+func (oo *OpenOLT) Delete_device(device *voltha.Device) error {
+	log.Infow("delete-device", log.Fields{"deviceId": device.Id})
+	ctx := context.Background()
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		if err := handler.DeleteDevice(ctx, device); err != nil {
+			log.Errorw("failed-to-handle-delete-device", log.Fields{"device-id": device.Id})
+		}
+		oo.deleteDeviceHandlerToMap(handler)
+		return nil
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Get_device_details unimplemented
+func (oo *OpenOLT) Get_device_details(device *voltha.Device) error {
+	return ErrNotImplemented
+}
+
+//Update_flows_bulk returns
+func (oo *OpenOLT) Update_flows_bulk(device *voltha.Device, flows *voltha.Flows, groups *voltha.FlowGroups, flowMetadata *voltha.FlowMetadata) error {
+	return ErrNotImplemented
+}
+
+//Update_flows_incrementally updates (add/remove) the flows on a given device
+func (oo *OpenOLT) Update_flows_incrementally(device *voltha.Device, flows *openflow_13.FlowChanges, groups *openflow_13.FlowGroupChanges, flowMetadata *voltha.FlowMetadata) error {
+	log.Debugw("Update_flows_incrementally", log.Fields{"deviceId": device.Id, "flows": flows, "flowMetadata": flowMetadata})
+	ctx := context.Background()
+	if handler := oo.getDeviceHandler(device.Id); handler != nil {
+		return handler.UpdateFlowsIncrementally(ctx, device, flows, groups, flowMetadata)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": device.Id}, nil).Log()
+}
+
+//Update_pm_config returns PmConfigs nil or error
+func (oo *OpenOLT) Update_pm_config(device *voltha.Device, pmConfigs *voltha.PmConfigs) error {
+	return ErrNotImplemented
+}
+
+//Receive_packet_out sends packet out to the device
+func (oo *OpenOLT) Receive_packet_out(deviceID string, egressPortNo int, packet *openflow_13.OfpPacketOut) error {
+	log.Debugw("Receive_packet_out", log.Fields{"deviceId": deviceID, "egress_port_no": egressPortNo, "pkt": packet})
+	ctx := context.Background()
+	if handler := oo.getDeviceHandler(deviceID); handler != nil {
+		return handler.PacketOut(ctx, egressPortNo, packet)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": deviceID}, nil).Log()
+}
+
+//Suppress_event unimplemented
+func (oo *OpenOLT) Suppress_event(filter *voltha.EventFilter) error {
+	return ErrNotImplemented
+}
+
+//Unsuppress_event  unimplemented
+func (oo *OpenOLT) Unsuppress_event(filter *voltha.EventFilter) error {
+	return ErrNotImplemented
+}
+
+//Download_image unimplemented
+func (oo *OpenOLT) Download_image(device *voltha.Device, request *voltha.ImageDownload) (*voltha.ImageDownload, error) {
+	return nil, ErrNotImplemented
+}
+
+//Get_image_download_status unimplemented
+func (oo *OpenOLT) Get_image_download_status(device *voltha.Device, request *voltha.ImageDownload) (*voltha.ImageDownload, error) {
+	return nil, ErrNotImplemented
+}
+
+//Cancel_image_download unimplemented
+func (oo *OpenOLT) Cancel_image_download(device *voltha.Device, request *voltha.ImageDownload) (*voltha.ImageDownload, error) {
+	return nil, ErrNotImplemented
+}
+
+//Activate_image_update unimplemented
+func (oo *OpenOLT) Activate_image_update(device *voltha.Device, request *voltha.ImageDownload) (*voltha.ImageDownload, error) {
+	return nil, ErrNotImplemented
+}
+
+//Revert_image_update unimplemented
+func (oo *OpenOLT) Revert_image_update(device *voltha.Device, request *voltha.ImageDownload) (*voltha.ImageDownload, error) {
+	return nil, ErrNotImplemented
+}
+
+// Enable_port to Enable PON/NNI interface
+func (oo *OpenOLT) Enable_port(deviceID string, port *voltha.Port) error {
+	log.Infow("Enable_port", log.Fields{"deviceId": deviceID, "port": port})
+	return oo.enableDisablePort(deviceID, port, true)
+}
+
+// Disable_port to Disable pon/nni interface
+func (oo *OpenOLT) Disable_port(deviceID string, port *voltha.Port) error {
+	log.Infow("Disable_port", log.Fields{"deviceId": deviceID, "port": port})
+	return oo.enableDisablePort(deviceID, port, false)
+}
+
+// enableDisablePort to Disable pon or Enable PON interface
+func (oo *OpenOLT) enableDisablePort(deviceID string, port *voltha.Port, enablePort bool) error {
+	log.Infow("enableDisablePort", log.Fields{"deviceId": deviceID, "port": port})
+	if port == nil {
+		return NewErrInvalidValue(log.Fields{
+			"reason":    "port cannot be nil",
+			"device-id": deviceID,
+			"port":      nil}, nil).Log()
+	}
+	if handler := oo.getDeviceHandler(deviceID); handler != nil {
+		log.Debugw("Enable_Disable_Port", log.Fields{"deviceId": deviceID, "port": port})
+		if enablePort {
+			if err := handler.EnablePort(port); err != nil {
+				log.Errorw("error-occurred-during-enable-port", log.Fields{"deviceID": deviceID, "port": port, "error": err})
+				return err
+			}
+		} else {
+			if err := handler.DisablePort(port); err != nil {
+				log.Errorw("error-occurred-during-disable-port", log.Fields{"Device": deviceID, "port": port})
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+//Child_device_lost deletes the ONU and its references from PONResources
+func (oo *OpenOLT) Child_device_lost(deviceID string, pPortNo uint32, onuID uint32) error {
+	log.Infow("Child-device-lost", log.Fields{"parentId": deviceID})
+	ctx := context.Background()
+	if handler := oo.getDeviceHandler(deviceID); handler != nil {
+		return handler.ChildDeviceLost(ctx, pPortNo, onuID)
+	}
+	return NewErrNotFound("device-handler", log.Fields{"device-id": deviceID}, nil).Log()
+}