diff --git a/internal/pkg/onuadaptercore/onu_metrics_manager.go b/internal/pkg/onuadaptercore/onu_metrics_manager.go
index 68c628c..3110501 100644
--- a/internal/pkg/onuadaptercore/onu_metrics_manager.go
+++ b/internal/pkg/onuadaptercore/onu_metrics_manager.go
@@ -19,8 +19,8 @@
 
 import (
 	"context"
-	"errors"
 	"fmt"
+	"github.com/looplab/fsm"
 	"github.com/opencord/omci-lib-go"
 	me "github.com/opencord/omci-lib-go/generated"
 	"github.com/opencord/voltha-lib-go/v4/pkg/log"
@@ -29,6 +29,29 @@
 	"time"
 )
 
+const (
+	// events of L2 PM FSM
+	l2PmEventInit     = "l2PmEventInit"
+	l2PmEventTick     = "l2PmEventTick"
+	l2PmEventSuccess  = "l2PmEventSuccess"
+	l2PmEventFailure  = "l2PmEventFailure"
+	l2PmEventAddMe    = "l2PmEventAddMe"
+	l2PmEventDeleteMe = "l2PmEventDeleteMe"
+	l2PmEventStop     = "l2PmEventStop"
+)
+const (
+	// states of L2 PM FSM
+	l2PmStNull        = "l2PmStNull"
+	l2PmStStarting    = "l2PmStStarting"
+	l2PmStSyncTime    = "l2PmStSyncTime"
+	l2PmStIdle        = "l2PmStIdle"
+	l2PmStCreatePmMe  = "l2PmStCreatePm"
+	l2PmStDeletePmMe  = "l2PmStDeletePmMe"
+	l2PmStCollectData = "l2PmStCollectData"
+)
+
+const cL2PmFsmIdleState = l2PmStIdle
+
 // general constants used for overall Metric Collection management
 const (
 	DefaultMetricCollectionFrequency = 15 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
@@ -46,7 +69,7 @@
 
 // OpticalPowerGroupMetrics specific constants
 const (
-	OpticalPowerGroupMetricName                = "OpticalPower"
+	OpticalPowerGroupMetricName                = "PON_Optical"
 	OpticalPowerGroupMetricEnabled             = true   // This setting can be changed from voltha NBI PmConfig configuration
 	OpticalPowerMetricGroupCollectionFrequency = 5 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
 )
@@ -61,17 +84,96 @@
 
 // UniStatusGroupMetrics specific constants
 const (
-	UniStatusGroupMetricName                = "UniStatus"
+	UniStatusGroupMetricName                = "UNI_Status"
 	UniStatusGroupMetricEnabled             = true   // This setting can be changed from voltha NBI PmConfig configuration
 	UniStatusMetricGroupCollectionFrequency = 5 * 60 // unit in seconds. This setting can be changed from voltha NBI PmConfig configuration
 )
 
+// *** Classical L2 PM Counters begin ***
+
+// EthernetBridgeHistory are supported ethernet bridge history counters fetched from
+// Ethernet Frame Performance Monitoring History Data Downstream and Ethernet Frame Performance Monitoring History Data Upstream MEs.
+var EthernetBridgeHistory = map[string]voltha.PmConfig_PmType{
+	"class_id":          voltha.PmConfig_CONTEXT,
+	"entity_id":         voltha.PmConfig_CONTEXT,
+	"interval_end_time": voltha.PmConfig_CONTEXT,
+	"parent_class_id":   voltha.PmConfig_CONTEXT,
+	"parent_entity_id":  voltha.PmConfig_CONTEXT,
+	"upstream":          voltha.PmConfig_CONTEXT,
+
+	"drop_events":         voltha.PmConfig_COUNTER,
+	"octets":              voltha.PmConfig_COUNTER,
+	"packets":             voltha.PmConfig_COUNTER,
+	"broadcast_packets":   voltha.PmConfig_COUNTER,
+	"multicast_packets":   voltha.PmConfig_COUNTER,
+	"crc_errored_packets": voltha.PmConfig_COUNTER,
+	"undersize_packets":   voltha.PmConfig_COUNTER,
+	"oversize_packets":    voltha.PmConfig_COUNTER,
+	"64_octets":           voltha.PmConfig_COUNTER,
+	"65_to_127_octets":    voltha.PmConfig_COUNTER,
+	"128_to_255_octets":   voltha.PmConfig_COUNTER,
+	"256_to_511_octets":   voltha.PmConfig_COUNTER,
+	"512_to_1023_octets":  voltha.PmConfig_COUNTER,
+	"1024_to_1518_octets": voltha.PmConfig_COUNTER,
+}
+
+// EthernetUniHistory are supported ethernet uni history counters fetched from
+// Ethernet Performance Monitoring History Data ME.
+var EthernetUniHistory = map[string]voltha.PmConfig_PmType{
+	"class_id":          voltha.PmConfig_CONTEXT,
+	"entity_id":         voltha.PmConfig_CONTEXT,
+	"interval_end_time": voltha.PmConfig_CONTEXT,
+
+	"fcs_errors":                        voltha.PmConfig_COUNTER,
+	"excessive_collision_counter":       voltha.PmConfig_COUNTER,
+	"late_collision_counter":            voltha.PmConfig_COUNTER,
+	"frames_too_long":                   voltha.PmConfig_COUNTER,
+	"buffer_overflows_on_rx":            voltha.PmConfig_COUNTER,
+	"buffer_overflows_on_tx":            voltha.PmConfig_COUNTER,
+	"single_collision_frame_counter":    voltha.PmConfig_COUNTER,
+	"multiple_collisions_frame_counter": voltha.PmConfig_COUNTER,
+	"sqe_counter":                       voltha.PmConfig_COUNTER,
+	"deferred_tx_counter":               voltha.PmConfig_COUNTER,
+	"internal_mac_tx_error_counter":     voltha.PmConfig_COUNTER,
+	"carrier_sense_error_counter":       voltha.PmConfig_COUNTER,
+	"alignment_error_counter":           voltha.PmConfig_COUNTER,
+	"internal_mac_rx_error_counter":     voltha.PmConfig_COUNTER,
+}
+
+// Constants specific for L2 PM collection
+const (
+	L2PmCollectionInterval = 15 * 60 // Unit in seconds. Do not change this as this fixed by OMCI specification for L2 PM counters
+	SyncTimeRetryInterval  = 15      // Unit seconds
+	L2PmCreateAttempts     = 3
+	L2PmCollectAttempts    = 3
+	MaxL2PMGetPayLoadSize  = 29
+)
+
+// EthernetUniHistoryName specific constants
+const (
+	EthernetBridgeHistoryName      = "Ethernet_Bridge_Port_History"
+	EthernetBridgeHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
+	EthernetBridgeHistoryFrequency = L2PmCollectionInterval
+)
+
+// EthernetBridgeHistory specific constants
+const (
+	EthernetUniHistoryName      = "Ethernet_UNI_History"
+	EthernetUniHistoryEnabled   = true // This setting can be changed from voltha NBI PmConfig configuration
+	EthernetUniHistoryFrequency = L2PmCollectionInterval
+)
+
+// *** Classical L2 PM Counters end   ***
+
 type groupMetric struct {
 	groupName              string
 	enabled                bool
 	frequency              uint32 // valid only if FrequencyOverride is enabled.
 	metricMap              map[string]voltha.PmConfig_PmType
 	nextCollectionInterval time.Time // valid only if FrequencyOverride is enabled.
+	isL2PMCounter          bool      // true for only L2 PM counters
+	collectAttempts        uint32    // number of attempts to collect L2 PM data
+	createRetryAttempts    uint32    // number of attempts to try creating the L2 PM ME
 }
 
 type standaloneMetric struct {
@@ -83,16 +185,25 @@
 
 type onuMetricsManager struct {
 	pDeviceHandler *deviceHandler
+	pAdaptFsm      *AdapterFsm
 
-	commMetricsChan      chan Message
-	opticalMetricsChan   chan me.AttributeValueMap
-	uniStatusMetricsChan chan me.AttributeValueMap
+	opticalMetricsChan             chan me.AttributeValueMap
+	uniStatusMetricsChan           chan me.AttributeValueMap
+	l2PmChan                       chan me.AttributeValueMap
+	syncTimeResponseChan           chan bool // true is success, false is fail
+	l2PmCreateOrDeleteResponseChan chan bool // true is success, false is fail
+
+	activeL2Pms  []string // list of active l2 pm MEs created on the ONU.
+	l2PmToDelete []string // list of L2 PMs to delete
+	l2PmToAdd    []string // list of L2 PM to add
 
 	groupMetricMap      map[string]*groupMetric
 	standaloneMetricMap map[string]*standaloneMetric
 
 	stopProcessingOmciResponses chan bool
 
+	stopTicks chan bool
+
 	nextGlobalMetricCollectionTime time.Time // valid only if pmConfig.FreqOverride is set to false.
 
 	onuMetricsManagerLock sync.RWMutex
@@ -109,10 +220,16 @@
 	logger.Debugw(ctx, "init-onuMetricsManager", log.Fields{"device-id": dh.deviceID})
 	metricsManager.pDeviceHandler = dh
 
-	metricsManager.commMetricsChan = make(chan Message)
+	commMetricsChan := make(chan Message)
 	metricsManager.opticalMetricsChan = make(chan me.AttributeValueMap)
 	metricsManager.uniStatusMetricsChan = make(chan me.AttributeValueMap)
+	metricsManager.l2PmChan = make(chan me.AttributeValueMap)
+
+	metricsManager.syncTimeResponseChan = make(chan bool)
+	metricsManager.l2PmCreateOrDeleteResponseChan = make(chan bool)
+
 	metricsManager.stopProcessingOmciResponses = make(chan bool)
+	metricsManager.stopTicks = make(chan bool)
 
 	metricsManager.groupMetricMap = make(map[string]*groupMetric)
 	metricsManager.standaloneMetricMap = make(map[string]*standaloneMetric)
@@ -154,6 +271,36 @@
 		}
 		dh.pmConfigs.Groups = append(dh.pmConfigs.Groups, &uniStatusGroupMetric)
 
+		// classical l2 pm counter start
+
+		// Populate ethernet bridge history group metrics
+		var ethBridgeHistoryConfigSlice []*voltha.PmConfig
+		for k, v := range EthernetBridgeHistory {
+			ethBridgeHistoryConfigSlice = append(ethBridgeHistoryConfigSlice, &voltha.PmConfig{Name: k, Type: v})
+		}
+		ethBridgeHistoryGroupMetric := voltha.PmGroupConfig{
+			GroupName: EthernetBridgeHistoryName,
+			Enabled:   EthernetBridgeHistoryEnabled && dh.pOpenOnuAc.metricsEnabled,
+			GroupFreq: EthernetBridgeHistoryFrequency,
+			Metrics:   ethBridgeHistoryConfigSlice,
+		}
+		dh.pmConfigs.Groups = append(dh.pmConfigs.Groups, &ethBridgeHistoryGroupMetric)
+
+		// Populate ethernet bridge history group metrics
+		var ethUniHistoryConfigSlice []*voltha.PmConfig
+		for k, v := range EthernetUniHistory {
+			ethUniHistoryConfigSlice = append(ethUniHistoryConfigSlice, &voltha.PmConfig{Name: k, Type: v})
+		}
+		ethUniHistoryGroupMetric := voltha.PmGroupConfig{
+			GroupName: EthernetUniHistoryName,
+			Enabled:   EthernetUniHistoryEnabled && dh.pOpenOnuAc.metricsEnabled,
+			GroupFreq: EthernetUniHistoryFrequency,
+			Metrics:   ethUniHistoryConfigSlice,
+		}
+		dh.pmConfigs.Groups = append(dh.pmConfigs.Groups, &ethUniHistoryGroupMetric)
+
+		// classical l2 pm counter end
+
 		// Add standalone metric (if present) after this (will be added to dh.pmConfigs.Metrics)
 	}
 
@@ -169,7 +316,12 @@
 			metricsManager.groupMetricMap[g.GroupName].metricMap = OpticalPowerGroupMetrics
 		case UniStatusGroupMetricName:
 			metricsManager.groupMetricMap[g.GroupName].metricMap = UniStatusGroupMetrics
-
+		case EthernetBridgeHistoryName:
+			metricsManager.groupMetricMap[g.GroupName].metricMap = EthernetBridgeHistory
+			metricsManager.groupMetricMap[g.GroupName].isL2PMCounter = true
+		case EthernetUniHistoryName:
+			metricsManager.groupMetricMap[g.GroupName].metricMap = EthernetUniHistory
+			metricsManager.groupMetricMap[g.GroupName].isL2PMCounter = true
 		default:
 			logger.Errorw(ctx, "unhandled-group-name", log.Fields{"groupName": g.GroupName})
 		}
@@ -189,6 +341,38 @@
 		}
 	}
 
+	metricsManager.pAdaptFsm = NewAdapterFsm("L2PmFSM", dh.deviceID, commMetricsChan)
+	if metricsManager.pAdaptFsm == nil {
+		logger.Errorw(ctx, "L2PMFsm AdapterFsm could not be instantiated!!", log.Fields{
+			"device-id": dh.deviceID})
+		return nil
+	}
+	// L2 PM FSM related state machine
+	metricsManager.pAdaptFsm.pFsm = fsm.NewFSM(
+		l2PmStNull,
+		fsm.Events{
+			{Name: l2PmEventInit, Src: []string{l2PmStNull}, Dst: l2PmStStarting},
+			{Name: l2PmEventTick, Src: []string{l2PmStStarting}, Dst: l2PmStSyncTime},
+			{Name: l2PmEventTick, Src: []string{l2PmStIdle, l2PmEventDeleteMe, l2PmEventAddMe}, Dst: l2PmStCollectData},
+			{Name: l2PmEventSuccess, Src: []string{l2PmStSyncTime, l2PmStCreatePmMe, l2PmStDeletePmMe, l2PmStCollectData}, Dst: l2PmStIdle},
+			{Name: l2PmEventFailure, Src: []string{l2PmStCreatePmMe, l2PmStDeletePmMe, l2PmStCollectData}, Dst: l2PmStIdle},
+			{Name: l2PmEventFailure, Src: []string{l2PmStSyncTime}, Dst: l2PmStSyncTime},
+			{Name: l2PmEventAddMe, Src: []string{l2PmStIdle}, Dst: l2PmStCreatePmMe},
+			{Name: l2PmEventDeleteMe, Src: []string{l2PmStIdle}, Dst: l2PmStDeletePmMe},
+			{Name: l2PmEventStop, Src: []string{l2PmStNull, l2PmStStarting, l2PmStSyncTime, l2PmStIdle, l2PmStCreatePmMe, l2PmStDeletePmMe, l2PmStCollectData}, Dst: l2PmStNull},
+		},
+		fsm.Callbacks{
+			"enter_state":                func(e *fsm.Event) { metricsManager.pAdaptFsm.logFsmStateChange(ctx, e) },
+			"enter_" + l2PmStNull:        func(e *fsm.Event) { metricsManager.l2PMFsmNull(ctx, e) },
+			"enter_" + l2PmStIdle:        func(e *fsm.Event) { metricsManager.l2PMFsmIdle(ctx, e) },
+			"enter_" + l2PmStStarting:    func(e *fsm.Event) { metricsManager.l2PMFsmStarting(ctx, e) },
+			"enter_" + l2PmStSyncTime:    func(e *fsm.Event) { metricsManager.l2PMFsmSyncTime(ctx, e) },
+			"enter_" + l2PmStCollectData: func(e *fsm.Event) { metricsManager.l2PmFsmCollectData(ctx, e) },
+			"enter_" + l2PmStCreatePmMe:  func(e *fsm.Event) { metricsManager.l2PmFsmCreatePM(ctx, e) },
+			"enter_" + l2PmStDeletePmMe:  func(e *fsm.Event) { metricsManager.l2PmFsmDeletePM(ctx, e) },
+		},
+	)
+
 	// initialize the next metric collection intervals.
 	metricsManager.initializeMetricCollectionTime(ctx)
 	logger.Info(ctx, "init-onuMetricsManager completed", log.Fields{"device-id": dh.deviceID})
@@ -201,7 +385,7 @@
 		mm.onuMetricsManagerLock.Lock()
 		defer mm.onuMetricsManagerLock.Unlock()
 		for _, v := range mm.groupMetricMap {
-			if v.enabled {
+			if v.enabled && !v.isL2PMCounter { // L2 PM counter collection is managed in a L2PmFsm
 				v.nextCollectionInterval = time.Now().Add(time.Duration(v.frequency) * time.Second)
 			}
 		}
@@ -258,7 +442,7 @@
 	mm.onuMetricsManagerLock.Lock()
 	defer mm.onuMetricsManagerLock.Unlock()
 	for k, v := range mm.groupMetricMap {
-		if k == aGroupName {
+		if k == aGroupName && !v.isL2PMCounter { // We cannot allow the L2 PM counter frequency to be updated. It is 15min fixed by OMCI spec
 			v.frequency = newGroupFreq
 			// update internal pm config
 			mm.pDeviceHandler.pmConfigs.Groups[groupSliceIdx].GroupFreq = newGroupFreq
@@ -339,12 +523,31 @@
 		if k == aGroupName && v.enabled != group.Enabled {
 			mm.pDeviceHandler.pmConfigs.Groups[groupSliceIdx].Enabled = group.Enabled
 			v.enabled = group.Enabled
-			// If the group is now enabled and frequency override is enabled, set the next group metric collection time
-			if group.Enabled && mm.pDeviceHandler.pmConfigs.FreqOverride {
-				v.nextCollectionInterval = time.Now().Add(time.Duration(v.frequency) * time.Second)
+			if group.Enabled {
+				if v.isL2PMCounter {
+					// If it is a L2 PM counter we need to mark the PM to be added
+					mm.l2PmToAdd = mm.appendIfMissing(mm.l2PmToAdd, v.groupName)
+					// If the group support flag toggles too soon, we need to delete the group name from l2PmToDelete slice
+					mm.l2PmToDelete = mm.removeIfFound(mm.l2PmToDelete, v.groupName)
+				} else if mm.pDeviceHandler.pmConfigs.FreqOverride { // otherwise just update the next collection interval
+					v.nextCollectionInterval = time.Now().Add(time.Duration(v.frequency) * time.Second)
+				}
+			} else { // group counter is disabled
+				if v.isL2PMCounter {
+					// If it is a L2 PM counter we need to mark the PM to be deleted
+					mm.l2PmToDelete = mm.appendIfMissing(mm.l2PmToDelete, v.groupName)
+					// If the group support flag toggles too soon, we need to delete the group name from l2PmToAdd slice
+					mm.l2PmToAdd = mm.removeIfFound(mm.l2PmToAdd, v.groupName)
+				}
 			}
 			updated = true
-			logger.Infow(ctx, "group metric support updated", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "groupName": aGroupName, "enabled": group.Enabled})
+			if v.isL2PMCounter {
+				logger.Infow(ctx, "l2 pm group metric support updated",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "groupName": aGroupName, "enabled": group.Enabled, "l2PmToAdd": mm.l2PmToAdd, "l2PmToDelete": mm.l2PmToDelete})
+			} else {
+				logger.Infow(ctx, "group metric support updated", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "groupName": aGroupName, "enabled": group.Enabled})
+			}
+			break
 		}
 	}
 
@@ -487,7 +690,7 @@
 		opticalMetrics := make(map[string]float32)
 		// Get the ANI-G instance optical power attributes
 		requestedAttributes := me.AttributeValueMap{"OpticalSignalLevel": 0, "TransmitOpticalLevel": 0}
-		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.AniGClassID, anigInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.commMetricsChan); meInstance != nil {
+		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.AniGClassID, anigInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
 			select {
 			case meAttributes = <-mm.opticalMetricsChan:
 				logger.Debugw(ctx, "received optical metrics", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
@@ -563,7 +766,7 @@
 		var meAttributes me.AttributeValueMap
 		// Get the UNI-G instance optical power attributes
 		requestedAttributes := me.AttributeValueMap{"AdministrativeState": 0}
-		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.UniGClassID, unigInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.commMetricsChan); meInstance != nil {
+		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.UniGClassID, unigInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
 			// Wait for metrics or timeout
 			select {
 			case meAttributes = <-mm.uniStatusMetricsChan:
@@ -608,7 +811,7 @@
 		pptpMetrics := make(map[string]float32)
 
 		requestedAttributes := me.AttributeValueMap{"SensedType": 0, "OperationalState": 0, "AdministrativeState": 0}
-		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.PhysicalPathTerminationPointEthernetUniClassID, pptpInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.commMetricsChan); meInstance != nil {
+		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.PhysicalPathTerminationPointEthernetUniClassID, pptpInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
 			// Wait for metrics or timeout
 			select {
 			case meAttributes = <-mm.uniStatusMetricsChan:
@@ -663,7 +866,7 @@
 		veipMetrics := make(map[string]float32)
 
 		requestedAttributes := me.AttributeValueMap{"OperationalState": 0, "AdministrativeState": 0}
-		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.VirtualEthernetInterfacePointClassID, veipInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.commMetricsChan); meInstance != nil {
+		if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, me.VirtualEthernetInterfacePointClassID, veipInstID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
 			// Wait for metrics or timeout
 			select {
 			case meAttributes = <-mm.uniStatusMetricsChan:
@@ -735,7 +938,7 @@
 		case <-mm.stopProcessingOmciResponses: // stop this routine
 			logger.Infow(ctx, "Stop routine to process OMCI-GET messages for device-id", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
 			return
-		case message, ok := <-mm.commMetricsChan:
+		case message, ok := <-mm.pAdaptFsm.commChan:
 			if !ok {
 				logger.Errorw(ctx, "Message couldn't be read from channel", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
 				continue
@@ -760,7 +963,12 @@
 	case omci.GetResponseType:
 		//TODO: error handling
 		_ = mm.handleOmciGetResponseMessage(ctx, msg)
-
+	case omci.SynchronizeTimeResponseType:
+		_ = mm.handleOmciSynchronizeTimeResponseMessage(ctx, msg)
+	case omci.CreateResponseType:
+		_ = mm.handleOmciCreateResponseMessage(ctx, msg)
+	case omci.DeleteResponseType:
+		_ = mm.handleOmciDeleteResponseMessage(ctx, msg)
 	default:
 		logger.Warnw(ctx, "Unknown Message Type", log.Fields{"msgType": msg.OmciMsg.MessageType})
 
@@ -794,20 +1002,52 @@
 		case me.VirtualEthernetInterfacePointClassID:
 			mm.uniStatusMetricsChan <- meAttributes
 			return nil
+		case me.EthernetFramePerformanceMonitoringHistoryDataUpstreamClassID,
+			me.EthernetFramePerformanceMonitoringHistoryDataDownstreamClassID,
+			me.EthernetPerformanceMonitoringHistoryDataClassID:
+			mm.l2PmChan <- meAttributes
 		default:
 			logger.Errorw(ctx, "unhandled omci get response message",
 				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
 		}
 	}
 
-	return errors.New("unhandled-omci-get-response-message")
+	return fmt.Errorf("unhandled-omci-get-response-message")
+}
+
+func (mm *onuMetricsManager) handleOmciSynchronizeTimeResponseMessage(ctx context.Context, msg OmciMessage) error {
+	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeSynchronizeTimeResponse)
+	if msgLayer == nil {
+		logger.Errorw(ctx, "omci Msg layer could not be detected for synchronize time response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be detected for synchronize time response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	msgObj, msgOk := msgLayer.(*omci.SynchronizeTimeResponse)
+	if !msgOk {
+		logger.Errorw(ctx, "omci Msg layer could not be assigned for synchronize time response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be assigned for synchronize time response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	logger.Debugw(ctx, "OMCI synchronize time response Data", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "data-fields": msgObj})
+	if msgObj.Result == me.Success {
+		switch msgObj.EntityClass {
+		case me.OnuGClassID:
+			logger.Infow(ctx, "omci synchronize time success", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+			mm.syncTimeResponseChan <- true
+			return nil
+		default:
+			logger.Errorw(ctx, "unhandled omci message",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
+		}
+	}
+	mm.syncTimeResponseChan <- false
+	logger.Errorf(ctx, "unhandled-omci-synchronize-time-response-message--error-code-%v", msgObj.Result)
+	return fmt.Errorf("unhandled-omci-synchronize-time-response-message--error-code-%v", msgObj.Result)
 }
 
 // flushMetricCollectionChannels flushes all metric collection channels for any stale OMCI responses
 func (mm *onuMetricsManager) flushMetricCollectionChannels(ctx context.Context) {
 	// flush commMetricsChan
 	select {
-	case <-mm.commMetricsChan:
+	case <-mm.pAdaptFsm.commChan:
 		logger.Debug(ctx, "flushed common metrics channel")
 	default:
 	}
@@ -825,4 +1065,860 @@
 		logger.Debug(ctx, "flushed uni status metrics channel")
 	default:
 	}
+
+	// flush syncTimeResponseChan
+	select {
+	case <-mm.syncTimeResponseChan:
+		logger.Debug(ctx, "flushed sync time response channel")
+	default:
+	}
+
+	// flush l2PmChan
+	select {
+	case <-mm.l2PmChan:
+		logger.Debug(ctx, "flushed L2 PM collection channel")
+	default:
+	}
+
+	// flush stopTicks
+	select {
+	case <-mm.stopTicks:
+		logger.Debug(ctx, "flushed stopTicks channel")
+	default:
+	}
+
+}
+
+// ** L2 PM FSM Handlers start **
+
+func (mm *onuMetricsManager) l2PMFsmStarting(ctx context.Context, e *fsm.Event) {
+	// Loop through all the group metrics
+	// If it is a L2 PM Interval metric and it is enabled, then if it is not in the
+	// list of active L2 PM list then mark it for creation
+	// It it is a L2 PM Interval metric and it is disabled, then if it is in the
+	// list of active L2 PM list then mark it for deletion
+	mm.onuMetricsManagerLock.Lock()
+	for n, g := range mm.groupMetricMap {
+		if g.isL2PMCounter { // it is a l2 pm counter
+			if g.enabled { // metric enabled.
+				found := false
+			inner1:
+				for _, v := range mm.activeL2Pms {
+					if v == n {
+						found = true // metric already present in active l2 pm list
+						break inner1
+					}
+				}
+				if !found { // metric not in active l2 pm list. Mark this to be added later
+					mm.l2PmToAdd = mm.appendIfMissing(mm.l2PmToAdd, n)
+				}
+			} else { // metric not enabled.
+				found := false
+			inner2:
+				for _, v := range mm.activeL2Pms {
+					if v == n {
+						found = true // metric is found in active l2 pm list
+						break inner2
+					}
+				}
+				if found { // metric is found in active l2 pm list. Mark this to be deleted later
+					mm.l2PmToDelete = mm.appendIfMissing(mm.l2PmToDelete, n)
+				}
+			}
+		}
+	}
+	mm.onuMetricsManagerLock.Unlock()
+	logger.Debugw(ctx, "pms to add and delete",
+		log.Fields{"device-id": mm.pDeviceHandler.deviceID, "pms-to-add": mm.l2PmToAdd, "pms-to-delete": mm.l2PmToDelete})
+	go func() {
+		// push a tick event to move to next state
+		if err := mm.pAdaptFsm.pFsm.Event(l2PmEventTick); err != nil {
+			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+		}
+	}()
+}
+
+func (mm *onuMetricsManager) l2PMFsmSyncTime(ctx context.Context, e *fsm.Event) {
+	// Sync time with the ONU to establish 15min boundary for PM collection.
+	if err := mm.syncTime(ctx); err != nil {
+		go func() {
+			time.Sleep(SyncTimeRetryInterval * time.Second) // retry to sync time after this timeout
+			// This will result in FSM attempting to sync time again
+			if err := mm.pAdaptFsm.pFsm.Event(l2PmEventFailure); err != nil {
+				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+			}
+		}()
+	}
+	// Initiate a tick generation routine every L2PmCollectionInterval
+	go mm.generateTicks(ctx)
+
+	go func() {
+		if err := mm.pAdaptFsm.pFsm.Event(l2PmEventSuccess); err != nil {
+			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+		}
+	}()
+}
+
+func (mm *onuMetricsManager) l2PMFsmNull(ctx context.Context, e *fsm.Event) {
+	// We need to reset the local data so that the L2 PM MEs are re-provisioned once the ONU is back up based on the latest PM CONFIG
+	mm.onuMetricsManagerLock.Lock()
+	mm.activeL2Pms = nil
+	mm.l2PmToAdd = nil
+	mm.l2PmToDelete = nil
+	mm.onuMetricsManagerLock.Unlock()
+}
+func (mm *onuMetricsManager) l2PMFsmIdle(ctx context.Context, e *fsm.Event) {
+	logger.Debugw(ctx, "Enter state idle", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+
+	mm.onuMetricsManagerLock.RLock()
+	numOfPmToDelete := len(mm.l2PmToDelete)
+	numOfPmToAdd := len(mm.l2PmToAdd)
+	mm.onuMetricsManagerLock.RUnlock()
+
+	if numOfPmToDelete > 0 {
+		logger.Debugw(ctx, "state idle - pms to delete", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "pms-to-delete": numOfPmToDelete})
+		go func() {
+			if err := mm.pAdaptFsm.pFsm.Event(l2PmEventDeleteMe); err != nil {
+				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+			}
+		}()
+	} else if numOfPmToAdd > 0 {
+		logger.Debugw(ctx, "state idle - pms to add", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "pms-to-add": numOfPmToAdd})
+		go func() {
+			if err := mm.pAdaptFsm.pFsm.Event(l2PmEventAddMe); err != nil {
+				logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+			}
+		}()
+	}
+}
+
+func (mm *onuMetricsManager) l2PmFsmCollectData(ctx context.Context, e *fsm.Event) {
+	logger.Debugw(ctx, "state collect data", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+	// Copy the activeL2Pms for which we want to collect the metrics since activeL2Pms can change dynamically
+	mm.onuMetricsManagerLock.RLock()
+	copyOfActiveL2Pms := make([]string, len(mm.activeL2Pms))
+	_ = copy(copyOfActiveL2Pms, mm.activeL2Pms)
+	mm.onuMetricsManagerLock.RUnlock()
+
+	for _, n := range copyOfActiveL2Pms {
+		switch n {
+		case EthernetBridgeHistoryName:
+			logger.Debugw(ctx, "state collect data - collecting data for EthernetFramePerformanceMonitoringHistoryData ME", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+			var metricInfoSlice []*voltha.MetricInformation
+			for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+				// Attach the EthernetFramePerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+				entityID := macBridgePortAniEID + uniPort.entityID
+				if metricInfo := mm.collectEthernetFramePerformanceMonitoringHistoryData(ctx, true, entityID); metricInfo != nil { // upstream
+					metricInfoSlice = append(metricInfoSlice, metricInfo)
+				}
+				if metricInfo := mm.collectEthernetFramePerformanceMonitoringHistoryData(ctx, false, entityID); metricInfo != nil { // downstream
+					metricInfoSlice = append(metricInfoSlice, metricInfo)
+				}
+			}
+			// Publish metrics if it is valid
+			if metricInfoSlice != nil {
+				mm.publishMetrics(ctx, metricInfoSlice)
+			} else {
+				// If collectAttempts exceeds L2PmCollectAttempts then remove it from activeL2Pms
+				// slice so that we do not collect data from that PM ME anymore
+				mm.onuMetricsManagerLock.Lock()
+				mm.groupMetricMap[n].collectAttempts++
+				if mm.groupMetricMap[n].collectAttempts > L2PmCollectAttempts {
+					mm.removeIfFound(mm.activeL2Pms, n)
+				}
+				logger.Warnw(ctx, "state collect data - no metrics collected",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "metricName": n, "collectAttempts": mm.groupMetricMap[n].collectAttempts})
+				mm.onuMetricsManagerLock.Unlock()
+			}
+		case EthernetUniHistoryName:
+			logger.Debugw(ctx, "state collect data - collecting data for EthernetPerformanceMonitoringHistoryData ME", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+			var metricInfoSlice []*voltha.MetricInformation
+			for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+				if uniPort.portType == uniPPTP { // This metric is only applicable for PPTP Uni Type
+					// Attach the EthernetFramePerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+					entityID := uniPort.entityID
+					if metricInfo := mm.collectEthernetUniHistoryData(ctx, entityID); metricInfo != nil { // upstream
+						metricInfoSlice = append(metricInfoSlice, metricInfo)
+					}
+				}
+			}
+			// Publish metrics if it is valid
+			if metricInfoSlice != nil {
+				mm.publishMetrics(ctx, metricInfoSlice)
+			} else {
+				// If collectAttempts exceeds L2PmCollectAttempts then remove it from activeL2Pms
+				// slice so that we do not collect data from that PM ME anymore
+				mm.onuMetricsManagerLock.Lock()
+				mm.groupMetricMap[n].collectAttempts++
+				if mm.groupMetricMap[n].collectAttempts > L2PmCollectAttempts {
+					mm.removeIfFound(mm.activeL2Pms, n)
+				}
+				logger.Warnw(ctx, "state collect data - no metrics collected",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "metricName": n, "collectAttempts": mm.groupMetricMap[n].collectAttempts})
+				mm.onuMetricsManagerLock.Unlock()
+			}
+		default:
+			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "name": n})
+		}
+	}
+	// Does not matter we send success or failure here.
+	// Those PMs that we failed to collect data will be attempted to collect again in the next PM collection cycle (assuming
+	// we have not exceed max attempts to collect the PM data)
+	go func() {
+		if err := mm.pAdaptFsm.pFsm.Event(l2PmEventSuccess); err != nil {
+			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+		}
+	}()
+}
+
+func (mm *onuMetricsManager) l2PmFsmCreatePM(ctx context.Context, e *fsm.Event) {
+	// Copy the l2PmToAdd for which we want to collect the metrics since l2PmToAdd can change dynamically
+	mm.onuMetricsManagerLock.RLock()
+	copyOfL2PmToAdd := make([]string, len(mm.l2PmToAdd))
+	_ = copy(copyOfL2PmToAdd, mm.l2PmToAdd)
+	mm.onuMetricsManagerLock.RUnlock()
+
+	logger.Debugw(ctx, "state create pm", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "pms-to-add": copyOfL2PmToAdd})
+	for _, n := range copyOfL2PmToAdd {
+		resp := false
+		switch n {
+		case EthernetBridgeHistoryName:
+			boolForDirection := make([]bool, 2) // stores true and false to indicate upstream and downstream directions.
+			boolForDirection = append(boolForDirection, true, false)
+			// Create ME twice, one for each direction. Boolean true is used to indicate upstream and false for downstream.
+			for _, direction := range boolForDirection {
+			inner1:
+				for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+					// Attach the EthernetFramePerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+					entityID := macBridgePortAniEID + uniPort.entityID
+					mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendCreateOrDeleteEthernetPerformanceMonitoringHistoryME(
+						ctx, ConstDefaultOmciTimeout, true, direction, true, mm.pAdaptFsm.commChan, entityID)
+					select {
+					case resp = <-mm.l2PmCreateOrDeleteResponseChan:
+						logger.Debugw(ctx, "received create EthernetFramePerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "resp": resp, "uni": uniPort.uniID})
+						if !resp {
+							// We will attempt to create the MEs again in the next L2 PM Collection cycle
+							break inner1
+						}
+					case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+						logger.Errorw(ctx, "timeout waiting for create EthernetFramePerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "uni": uniPort.uniID})
+					}
+				}
+			}
+		case EthernetUniHistoryName:
+
+		inner2:
+			for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+				if uniPort.portType == uniPPTP { // This metric is only applicable for PPTP Uni Type
+					// Attach the EthernetPerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+					entityID := uniPort.entityID
+					mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendCreateOrDeleteEthernetUniHistoryME(
+						ctx, ConstDefaultOmciTimeout, true, true, mm.pAdaptFsm.commChan, entityID)
+					select {
+					case resp = <-mm.l2PmCreateOrDeleteResponseChan:
+						logger.Debugw(ctx, "received create EthernetPerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "resp": resp, "uni": uniPort.uniID})
+						if !resp {
+							// We will attempt to create the MEs again in the next L2 PM Collection cycle
+							break inner2
+						}
+					case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+						logger.Errorw(ctx, "timeout waiting for create EthernetPerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "uni": uniPort.uniID})
+					}
+				}
+			}
+		default:
+			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "name": n})
+		}
+		// On success Update the local list maintained for active PMs and PMs to add
+		if resp {
+			mm.onuMetricsManagerLock.Lock()
+			mm.activeL2Pms = mm.appendIfMissing(mm.activeL2Pms, n)
+			mm.l2PmToAdd = mm.removeIfFound(mm.l2PmToAdd, n)
+			mm.onuMetricsManagerLock.Unlock()
+		} else {
+			// If createRetryAttempts exceeds L2PmCreateAttempts then locally disable the PM
+			// and also remove it from l2PmToAdd slice so that we do not try to create the PM ME anymore
+			mm.onuMetricsManagerLock.Lock()
+			mm.groupMetricMap[n].createRetryAttempts++
+			if mm.groupMetricMap[n].createRetryAttempts > L2PmCreateAttempts {
+				mm.groupMetricMap[n].enabled = false
+				mm.removeIfFound(mm.l2PmToAdd, n)
+			}
+			logger.Warnw(ctx, "state create pm - failed to create pm",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "metricName": n, "createRetryAttempts": mm.groupMetricMap[n].createRetryAttempts})
+			mm.onuMetricsManagerLock.Unlock()
+		}
+	}
+	// Does not matter we send success or failure here.
+	// Those PMs that we failed to create will be attempted to create again in the next PM creation cycle (assuming
+	// we have not exceed max attempts to create the PM ME)
+	go func() {
+		if err := mm.pAdaptFsm.pFsm.Event(l2PmEventSuccess); err != nil {
+			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+		}
+	}()
+}
+
+func (mm *onuMetricsManager) l2PmFsmDeletePM(ctx context.Context, e *fsm.Event) {
+	// Copy the l2PmToDelete for which we want to collect the metrics since l2PmToDelete can change dynamically
+	mm.onuMetricsManagerLock.RLock()
+	copyOfL2PmToDelete := make([]string, len(mm.l2PmToDelete))
+	_ = copy(copyOfL2PmToDelete, mm.l2PmToDelete)
+	mm.onuMetricsManagerLock.RUnlock()
+
+	logger.Debugw(ctx, "state delete pm", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "pms-to-delete": mm.l2PmToDelete})
+	for _, n := range copyOfL2PmToDelete {
+		resp := false
+		switch n {
+		case EthernetBridgeHistoryName:
+			boolForDirection := make([]bool, 2) // stores true and false to indicate upstream and downstream directions.
+			boolForDirection = append(boolForDirection, true, false)
+			// Create ME twice, one for each direction. Boolean true is used to indicate upstream and false for downstream.
+			for _, direction := range boolForDirection {
+			inner1:
+				for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+					// Attach the EthernetFramePerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+					entityID := macBridgePortAniEID + uniPort.entityID
+					mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendCreateOrDeleteEthernetPerformanceMonitoringHistoryME(
+						ctx, ConstDefaultOmciTimeout, true, direction, false, mm.pAdaptFsm.commChan, entityID)
+					select {
+					case resp = <-mm.l2PmCreateOrDeleteResponseChan:
+						logger.Debugw(ctx, "received delete EthernetFramePerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "resp": resp, "uni": uniPort.uniID})
+						if !resp {
+							// We will attempt to delete the MEs again in the next L2 PM Collection cycle
+							break inner1
+						}
+					case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+						logger.Errorw(ctx, "timeout waiting for delete EthernetFramePerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "uni": uniPort.uniID})
+					}
+				}
+			}
+		case EthernetUniHistoryName:
+
+		inner2:
+			for _, uniPort := range mm.pDeviceHandler.uniEntityMap {
+				if uniPort.portType == uniPPTP { // This metric is only applicable for PPTP Uni Type
+					// Attach the EthernetPerformanceMonitoringHistoryData ME to MacBridgePortConfigData on the UNI port
+					entityID := uniPort.entityID
+					mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendCreateOrDeleteEthernetUniHistoryME(
+						ctx, ConstDefaultOmciTimeout, true, false, mm.pAdaptFsm.commChan, entityID)
+					select {
+					case resp = <-mm.l2PmCreateOrDeleteResponseChan:
+						logger.Debugw(ctx, "received delete EthernetPerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "resp": resp, "uni": uniPort.uniID})
+						if !resp {
+							// We will attempt to delete the MEs again in the next L2 PM Collection cycle
+							break inner2
+						}
+					case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+						logger.Errorw(ctx, "timeout waiting for delete EthernetPerformanceMonitoringHistoryData l2 pm me response",
+							log.Fields{"device-id": mm.pDeviceHandler.deviceID, "uni": uniPort.uniID})
+					}
+				}
+			}
+		default:
+			logger.Errorw(ctx, "unsupported l2 pm", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "name": n})
+		}
+		// On success Update the local list maintained for active PMs and PMs to delete
+		if resp {
+			mm.onuMetricsManagerLock.Lock()
+			mm.activeL2Pms = mm.removeIfFound(mm.activeL2Pms, n)
+			mm.l2PmToDelete = mm.removeIfFound(mm.l2PmToDelete, n)
+			mm.onuMetricsManagerLock.Unlock()
+		}
+	}
+	// Does not matter we send success or failure here.
+	// Those PMs that we failed to delete will be attempted to create again in the next PM collection cycle
+	go func() {
+		if err := mm.pAdaptFsm.pFsm.Event(l2PmEventSuccess); err != nil {
+			logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+		}
+	}()
+}
+
+// ** L2 PM FSM Handlers end **
+
+// syncTime synchronizes time with the ONU to establish a 15 min boundary for PM collection and reporting.
+func (mm *onuMetricsManager) syncTime(ctx context.Context) error {
+	if err := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendSyncTime(ctx, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); err != nil {
+		logger.Errorw(ctx, "cannot send sync time request", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return err
+	}
+
+	select {
+	case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+		logger.Errorf(ctx, "timed out waiting for sync time response from onu", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("timed-out-waiting-for-sync-time-response-%v", mm.pDeviceHandler.deviceID)
+	case syncTimeRes := <-mm.syncTimeResponseChan:
+		if !syncTimeRes {
+			return fmt.Errorf("failed-to-sync-time-%v", mm.pDeviceHandler.deviceID)
+		}
+		logger.Infow(ctx, "sync time success", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return nil
+	}
+}
+
+func (mm *onuMetricsManager) collectEthernetFramePerformanceMonitoringHistoryData(ctx context.Context, upstream bool, entityID uint16) *voltha.MetricInformation {
+	var mEnt *me.ManagedEntity
+	var omciErr me.OmciErrors
+	var classID me.ClassID
+	var meAttributes me.AttributeValueMap
+	logger.Debugw(ctx, "collecting data for EthernetFramePerformanceMonitoringHistoryData", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream})
+	meParam := me.ParamData{EntityID: entityID}
+	if upstream {
+		if mEnt, omciErr = me.NewEthernetFramePerformanceMonitoringHistoryDataUpstream(meParam); omciErr == nil || mEnt == nil || omciErr.GetError() != nil {
+			logger.Errorw(ctx, "error creating me", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream})
+			return nil
+		}
+		classID = me.EthernetFramePerformanceMonitoringHistoryDataUpstreamClassID
+	} else {
+		if mEnt, omciErr = me.NewEthernetFramePerformanceMonitoringHistoryDataDownstream(meParam); omciErr == nil || mEnt == nil || omciErr.GetError() != nil {
+			logger.Errorw(ctx, "error creating me", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream})
+			return nil
+		}
+		classID = me.EthernetFramePerformanceMonitoringHistoryDataDownstreamClassID
+	}
+
+	requestedAttributes := make(me.AttributeValueMap)
+	size := 0
+	intervalEndTime := -1
+	ethPMHistData := make(map[string]float32)
+
+	for _, v := range mEnt.GetAttributeDefinitions() {
+		if (v.Size + size) <= MaxL2PMGetPayLoadSize {
+			requestedAttributes[v.Name] = v.DefValue
+			size = v.Size + size
+		} else { // We exceeded the allow omci get size
+			// Let's collect the attributes via get now and collect remaining in the next iteration
+			if err := mm.populateEthernetBridgeHistoryMetrics(ctx, upstream, classID, entityID, meAttributes, requestedAttributes, ethPMHistData, &intervalEndTime); err != nil {
+				logger.Errorw(ctx, "error during metric collection",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream, "err": err})
+				return nil
+			}
+			size = 0                                         // reset size
+			requestedAttributes = make(me.AttributeValueMap) // reset map
+		}
+	}
+	// Collect the omci get attributes for the last bunch of attributes.
+	if len(requestedAttributes) > 0 {
+		if err := mm.populateEthernetBridgeHistoryMetrics(ctx, upstream, classID, entityID, meAttributes, requestedAttributes, ethPMHistData, &intervalEndTime); err != nil {
+			logger.Errorw(ctx, "error during metric collection",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream, "err": err})
+			return nil
+		}
+	}
+
+	// Populate some relevant context for the EthernetFramePerformanceMonitoringHistoryData PM
+	ethPMHistData["class_id"] = float32(classID)
+	ethPMHistData["interval_end_time"] = float32(intervalEndTime)
+	ethPMHistData["parent_class_id"] = float32(me.MacBridgeConfigurationDataClassID) // EthernetFramePerformanceMonitoringHistoryData is attached to MBPCD ME
+	ethPMHistData["parent_entity_id"] = float32(entityID)
+	if upstream {
+		ethPMHistData["upstream"] = float32(1)
+	} else {
+		ethPMHistData["upstream"] = float32(0)
+	}
+
+	metricsContext := make(map[string]string)
+	metricsContext["onuID"] = fmt.Sprintf("%d", mm.pDeviceHandler.device.ProxyAddress.OnuId)
+	metricsContext["intfID"] = fmt.Sprintf("%d", mm.pDeviceHandler.device.ProxyAddress.ChannelId)
+	metricsContext["devicetype"] = mm.pDeviceHandler.DeviceType
+
+	raisedTs := time.Now().Unix()
+	mmd := voltha.MetricMetaData{
+		Title:           EthernetBridgeHistoryName,
+		Ts:              float64(raisedTs),
+		Context:         metricsContext,
+		DeviceId:        mm.pDeviceHandler.deviceID,
+		LogicalDeviceId: mm.pDeviceHandler.logicalDeviceID,
+		SerialNo:        mm.pDeviceHandler.device.SerialNumber,
+	}
+
+	// create slice of metrics given that there could be more than one VEIP instance
+	metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: ethPMHistData}
+	logger.Debugw(ctx, "collecting data for EthernetFramePerformanceMonitoringHistoryData successful",
+		log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "upstream": upstream, "metricInfo": metricInfo})
+	return &metricInfo
+}
+
+func (mm *onuMetricsManager) collectEthernetUniHistoryData(ctx context.Context, entityID uint16) *voltha.MetricInformation {
+	var mEnt *me.ManagedEntity
+	var omciErr me.OmciErrors
+	var classID me.ClassID
+	var meAttributes me.AttributeValueMap
+	logger.Debugw(ctx, "collecting data for EthernetFramePerformanceMonitoringHistoryData", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID})
+	meParam := me.ParamData{EntityID: entityID}
+	if mEnt, omciErr = me.NewEthernetPerformanceMonitoringHistoryData(meParam); omciErr == nil || mEnt == nil || omciErr.GetError() != nil {
+		logger.Errorw(ctx, "error creating me", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID})
+		return nil
+	}
+	classID = me.EthernetPerformanceMonitoringHistoryDataClassID
+
+	requestedAttributes := make(me.AttributeValueMap)
+	size := 0
+	intervalEndTime := -1
+	ethUniHistData := make(map[string]float32)
+
+	for _, v := range mEnt.GetAttributeDefinitions() {
+		if (v.Size + size) <= MaxL2PMGetPayLoadSize {
+			requestedAttributes[v.Name] = v.DefValue
+			size = v.Size + size
+		} else { // We exceeded the allow omci get size
+			// Let's collect the attributes via get now and collect remaining in the next iteration
+			if err := mm.populateEthernetUniHistoryMetrics(ctx, classID, entityID, meAttributes, requestedAttributes, ethUniHistData, &intervalEndTime); err != nil {
+				logger.Errorw(ctx, "error during metric collection",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "err": err})
+				return nil
+			}
+			size = 0                                         // reset size
+			requestedAttributes = make(me.AttributeValueMap) // reset map
+		}
+	}
+	// Collect the omci get attributes for the last bunch of attributes.
+	if len(requestedAttributes) > 0 {
+		if err := mm.populateEthernetUniHistoryMetrics(ctx, classID, entityID, meAttributes, requestedAttributes, ethUniHistData, &intervalEndTime); err != nil {
+			logger.Errorw(ctx, "error during metric collection",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "err": err})
+			return nil
+		}
+	}
+
+	// Populate some relevant context for the EthernetPerformanceMonitoringHistoryData PM
+	ethUniHistData["class_id"] = float32(classID)
+	ethUniHistData["interval_end_time"] = float32(intervalEndTime)
+
+	metricsContext := make(map[string]string)
+	metricsContext["onuID"] = fmt.Sprintf("%d", mm.pDeviceHandler.device.ProxyAddress.OnuId)
+	metricsContext["intfID"] = fmt.Sprintf("%d", mm.pDeviceHandler.device.ProxyAddress.ChannelId)
+	metricsContext["devicetype"] = mm.pDeviceHandler.DeviceType
+
+	raisedTs := time.Now().Unix()
+	mmd := voltha.MetricMetaData{
+		Title:           EthernetUniHistoryName,
+		Ts:              float64(raisedTs),
+		Context:         metricsContext,
+		DeviceId:        mm.pDeviceHandler.deviceID,
+		LogicalDeviceId: mm.pDeviceHandler.logicalDeviceID,
+		SerialNo:        mm.pDeviceHandler.device.SerialNumber,
+	}
+
+	// create slice of metrics given that there could be more than one PPTP instance
+	metricInfo := voltha.MetricInformation{Metadata: &mmd, Metrics: ethUniHistData}
+	logger.Debugw(ctx, "collecting data for EthernetPerformanceMonitoringHistoryData successful",
+		log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID, "metricInfo": metricInfo})
+	return &metricInfo
+}
+
+// nolint: gocyclo
+func (mm *onuMetricsManager) populateEthernetBridgeHistoryMetrics(ctx context.Context, upstream bool, classID me.ClassID, entityID uint16,
+	meAttributes me.AttributeValueMap, requestedAttributes me.AttributeValueMap, ethPMHistData map[string]float32, intervalEndTime *int) error {
+	// Make sure "IntervalEndTime" is part of the requested attributes as we need this to compare the get responses when get request is multipart
+	if _, ok := requestedAttributes["IntervalEndTime"]; !ok {
+		requestedAttributes["IntervalEndTime"] = 0
+	}
+	if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, classID, entityID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
+		select {
+		case meAttributes = <-mm.l2PmChan:
+			logger.Debugw(ctx, "received ethernet pm history data metrics",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "upstream": upstream, "entityID": entityID})
+		case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+			logger.Errorw(ctx, "timeout waiting for omci-get response for ethernet pm history data",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "upstream": upstream, "entityID": entityID})
+			// The metrics will be empty in this case
+			return fmt.Errorf("timeout-during-l2-pm-collection-for-ethernet-bridge-history-%v", mm.pDeviceHandler.deviceID)
+		}
+		// verify that interval end time has not changed during metric collection. If it changed, we abort the procedure
+		if *intervalEndTime == -1 { // first time
+			// Update the interval end time
+			if val, ok := meAttributes["IntervalEndTime"]; ok && val != nil {
+				*intervalEndTime = int(meAttributes["IntervalEndTime"].(uint8))
+			}
+		} else {
+			var currIntervalEndTime int
+			if val, ok := meAttributes["IntervalEndTime"]; ok && val != nil {
+				currIntervalEndTime = int(meAttributes["IntervalEndTime"].(uint8))
+			}
+			if currIntervalEndTime != *intervalEndTime { // interval end time changed during metric collection
+				logger.Errorw(ctx, "interval end time changed during metrics collection for ethernet pm history data",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID,
+						"currIntervalEndTime": *intervalEndTime, "newIntervalEndTime": currIntervalEndTime})
+				return fmt.Errorf("interval-end-time-changed-during-metric-collection-for-ethernet-bridge-history-%v", mm.pDeviceHandler.deviceID)
+			}
+		}
+	}
+	for k := range EthernetBridgeHistory {
+		// populate ethPMHistData only if metric key not already present (or populated), since it is possible that we populate
+		// the attributes in multiple iterations for a given L2 PM ME as there is a limit on the max OMCI GET payload size.
+		if _, ok := ethPMHistData[k]; !ok {
+			switch k {
+			case "drop_events":
+				if val, ok := meAttributes["DropEvents"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "octets":
+				if val, ok := meAttributes["Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "packets":
+				if val, ok := meAttributes["Packets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "broadcast_packets":
+				if val, ok := meAttributes["BroadcastPackets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "multicast_packets":
+				if val, ok := meAttributes["MulticastPackets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "crc_errored_packets":
+				if val, ok := meAttributes["CrcErroredPackets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "undersize_packets":
+				if val, ok := meAttributes["UndersizePackets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "oversize_packets":
+				if val, ok := meAttributes["OversizePackets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "64_octets":
+				if val, ok := meAttributes["Packets64Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "65_to_127_octets":
+				if val, ok := meAttributes["Packets65To127Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "128_to_255_octets":
+				if val, ok := meAttributes["Packets128To255Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "256_to_511_octets":
+				if val, ok := meAttributes["Packets256To511Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "512_to_1023_octets":
+				if val, ok := meAttributes["Packets512To1023Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			case "1024_to_1518_octets":
+				if val, ok := meAttributes["Packets1024To1518Octets"]; ok && val != nil {
+					ethPMHistData[k] = float32(val.(uint32))
+				}
+			default:
+				// do nothing
+			}
+		}
+	}
+	return nil
+}
+
+// nolint: gocyclo
+func (mm *onuMetricsManager) populateEthernetUniHistoryMetrics(ctx context.Context, classID me.ClassID, entityID uint16,
+	meAttributes me.AttributeValueMap, requestedAttributes me.AttributeValueMap, ethPMUniHistData map[string]float32, intervalEndTime *int) error {
+	// Make sure "IntervalEndTime" is part of the requested attributes as we need this to compare the get responses when get request is multipart
+	if _, ok := requestedAttributes["IntervalEndTime"]; !ok {
+		requestedAttributes["IntervalEndTime"] = 0
+	}
+	if meInstance := mm.pDeviceHandler.pOnuOmciDevice.PDevOmciCC.sendGetMe(ctx, classID, entityID, requestedAttributes, ConstDefaultOmciTimeout, true, mm.pAdaptFsm.commChan); meInstance != nil {
+		select {
+		case meAttributes = <-mm.l2PmChan:
+			logger.Debugw(ctx, "received ethernet uni history data metrics",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID})
+		case <-time.After(time.Duration(ConstDefaultOmciTimeout) * time.Second):
+			logger.Errorw(ctx, "timeout waiting for omci-get response for ethernet uni history data",
+				log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID})
+			// The metrics will be empty in this case
+			return fmt.Errorf("timeout-during-l2-pm-collection-for-ethernet-uni-history-%v", mm.pDeviceHandler.deviceID)
+		}
+		// verify that interval end time has not changed during metric collection. If it changed, we abort the procedure
+		if *intervalEndTime == -1 { // first time
+			// Update the interval end time
+			if val, ok := meAttributes["IntervalEndTime"]; ok && val != nil {
+				*intervalEndTime = int(meAttributes["IntervalEndTime"].(uint8))
+			}
+		} else {
+			var currIntervalEndTime int
+			if val, ok := meAttributes["IntervalEndTime"]; ok && val != nil {
+				currIntervalEndTime = int(meAttributes["IntervalEndTime"].(uint8))
+			}
+			if currIntervalEndTime != *intervalEndTime { // interval end time changed during metric collection
+				logger.Errorw(ctx, "interval end time changed during metrics collection for ethernet uni history data",
+					log.Fields{"device-id": mm.pDeviceHandler.deviceID, "entityID": entityID,
+						"currIntervalEndTime": *intervalEndTime, "newIntervalEndTime": currIntervalEndTime})
+				return fmt.Errorf("interval-end-time-changed-during-metric-collection-for-ethernet-uni-history-%v", mm.pDeviceHandler.deviceID)
+			}
+		}
+	}
+	for k := range EthernetUniHistory {
+		// populate ethPMUniHistData only if metric key not already present (or populated), since it is possible that we populate
+		// the attributes in multiple iterations for a given L2 PM ME as there is a limit on the max OMCI GET payload size.
+		if _, ok := ethPMUniHistData[k]; !ok {
+			switch k {
+			case "fcs_errors":
+				if val, ok := meAttributes["FcsErrors"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "excessive_collision_counter":
+				if val, ok := meAttributes["ExcessiveCollisionCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "late_collision_counter":
+				if val, ok := meAttributes["LateCollisionCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "frames_too_long":
+				if val, ok := meAttributes["FramesTooLong"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "buffer_overflows_on_rx":
+				if val, ok := meAttributes["BufferOverflowsOnReceive"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "buffer_overflows_on_tx":
+				if val, ok := meAttributes["BufferOverflowsOnTransmit"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "single_collision_frame_counter":
+				if val, ok := meAttributes["SingleCollisionFrameCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "multiple_collisions_frame_counter":
+				if val, ok := meAttributes["MultipleCollisionsFrameCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "sqe_counter":
+				if val, ok := meAttributes["SqeCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "deferred_tx_counter":
+				if val, ok := meAttributes["DeferredTransmissionCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "internal_mac_tx_error_counter":
+				if val, ok := meAttributes["InternalMacTransmitErrorCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "carrier_sense_error_counter":
+				if val, ok := meAttributes["CarrierSenseErrorCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "alignment_error_counter":
+				if val, ok := meAttributes["AlignmentErrorCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			case "internal_mac_rx_error_counter":
+				if val, ok := meAttributes["InternalMacReceiveErrorCounter"]; ok && val != nil {
+					ethPMUniHistData[k] = float32(val.(uint32))
+				}
+			default:
+				// do nothing
+			}
+		}
+	}
+	return nil
+}
+
+func (mm *onuMetricsManager) handleOmciCreateResponseMessage(ctx context.Context, msg OmciMessage) error {
+	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeCreateResponse)
+	if msgLayer == nil {
+		logger.Errorw(ctx, "omci Msg layer could not be detected for create response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be detected for create response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	msgObj, msgOk := msgLayer.(*omci.CreateResponse)
+	if !msgOk {
+		logger.Errorw(ctx, "omci Msg layer could not be assigned for create response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be assigned for delete response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	logger.Debugw(ctx, "OMCI create response Data", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "data-fields": msgObj})
+	switch msgObj.EntityClass {
+	case me.EthernetFramePerformanceMonitoringHistoryDataUpstreamClassID,
+		me.EthernetFramePerformanceMonitoringHistoryDataDownstreamClassID,
+		me.EthernetPerformanceMonitoringHistoryDataClassID:
+		// If the result is me.InstanceExists it means the entity was already created. It is ok handled that as success
+		if msgObj.Result == me.Success || msgObj.Result == me.InstanceExists {
+			mm.l2PmCreateOrDeleteResponseChan <- true
+		} else {
+			logger.Warnw(ctx, "failed to create me", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
+			mm.l2PmCreateOrDeleteResponseChan <- false
+		}
+		return nil
+	default:
+		logger.Errorw(ctx, "unhandled omci create response message",
+			log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
+	}
+	return fmt.Errorf("unhandled-omci-create-response-message-%v", mm.pDeviceHandler.deviceID)
+}
+
+func (mm *onuMetricsManager) handleOmciDeleteResponseMessage(ctx context.Context, msg OmciMessage) error {
+	msgLayer := (*msg.OmciPacket).Layer(omci.LayerTypeDeleteResponse)
+	if msgLayer == nil {
+		logger.Errorw(ctx, "omci Msg layer could not be detected for delete response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be detected for create response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	msgObj, msgOk := msgLayer.(*omci.DeleteResponse)
+	if !msgOk {
+		logger.Errorw(ctx, "omci Msg layer could not be assigned for delete response - handling stopped", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+		return fmt.Errorf("omci Msg layer could not be assigned for delete response - handling stopped: %s", mm.pDeviceHandler.deviceID)
+	}
+	logger.Debugw(ctx, "OMCI delete response Data", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "data-fields": msgObj})
+	switch msgObj.EntityClass {
+	case me.EthernetFramePerformanceMonitoringHistoryDataUpstreamClassID,
+		me.EthernetFramePerformanceMonitoringHistoryDataDownstreamClassID,
+		me.EthernetPerformanceMonitoringHistoryDataClassID:
+		// If the result is me.UnknownInstance it means the entity was already deleted. It is ok handled that as success
+		if msgObj.Result == me.Success || msgObj.Result == me.UnknownInstance {
+			mm.l2PmCreateOrDeleteResponseChan <- true
+		} else {
+			logger.Warnw(ctx, "failed to delete me", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
+			mm.l2PmCreateOrDeleteResponseChan <- false
+		}
+		return nil
+	default:
+		logger.Errorw(ctx, "unhandled omci delete response message",
+			log.Fields{"device-id": mm.pDeviceHandler.deviceID, "class-id": msgObj.EntityClass})
+	}
+	return fmt.Errorf("unhandled-omci-delete-response-message-%v", mm.pDeviceHandler.deviceID)
+}
+
+func (mm *onuMetricsManager) generateTicks(ctx context.Context) {
+	for {
+		select {
+		case <-time.After(L2PmCollectionInterval * time.Second):
+			go func() {
+				if err := mm.pAdaptFsm.pFsm.Event(l2PmEventTick); err != nil {
+					logger.Errorw(ctx, "error calling event", log.Fields{"device-id": mm.pDeviceHandler.deviceID, "err": err})
+				}
+			}()
+		case <-mm.stopTicks:
+			logger.Infow(ctx, "stopping ticks", log.Fields{"device-id": mm.pDeviceHandler.deviceID})
+			return
+		}
+	}
+}
+
+func (mm *onuMetricsManager) appendIfMissing(slice []string, n string) []string {
+	for _, ele := range slice {
+		if ele == n {
+			return slice
+		}
+	}
+	return append(slice, n)
+}
+
+func (mm *onuMetricsManager) removeIfFound(slice []string, n string) []string {
+	for i, ele := range slice {
+		if ele == n {
+			return append(slice[:i], slice[i+1:]...)
+		}
+	}
+	return slice
 }