diff --git a/adaptercore/device_handler.go b/adaptercore/device_handler.go
index 60c128a..447079d 100644
--- a/adaptercore/device_handler.go
+++ b/adaptercore/device_handler.go
@@ -1117,6 +1117,16 @@
 	}
 	return ""
 }
+func (dh *DeviceHandler) deStringifySerialNumber(serialNum string) (*oop.SerialNumber, error) {
+	decodedStr, err := hex.DecodeString(serialNum[4:])
+	if err != nil {
+		return nil, err
+	}
+	return &oop.SerialNumber{
+		VendorId:       []byte(serialNum[:4]),
+		VendorSpecific: []byte(decodedStr),
+	}, nil
+}
 
 func (dh *DeviceHandler) stringifyVendorSpecific(vendorSpecific []byte) string {
 	tmp := fmt.Sprintf("%x", (uint32(vendorSpecific[0])>>4)&0x0f) +
@@ -1755,3 +1765,64 @@
 		}
 	}
 }
+
+// ChildDeviceLost deletes ONU and clears pon resources related to it.
+func (dh *DeviceHandler) ChildDeviceLost(ctx context.Context, pPortNo uint32, onuID uint32) error {
+	log.Debugw("child-device-lost", log.Fields{"pdeviceID": dh.device.Id})
+	IntfID := PortNoToIntfID(pPortNo, voltha.Port_PON_OLT)
+	onuKey := dh.formOnuKey(IntfID, onuID)
+	onuDevice, ok := dh.onus.Load(onuKey)
+	if !ok {
+		return NewErrAdapter("failed-to-load-onu-details",
+			log.Fields{
+				"device-id":    dh.deviceID,
+				"onu-id":       onuID,
+				"interface-id": IntfID}, nil).Log()
+	}
+	var sn *oop.SerialNumber
+	var err error
+	if sn, err = dh.deStringifySerialNumber(onuDevice.(*OnuDevice).serialNumber); err != nil {
+		return NewErrAdapter("failed-to-destringify-serial-number",
+			log.Fields{
+				"devicer-id":    dh.deviceID,
+				"serial-number": onuDevice.(*OnuDevice).serialNumber}, err).Log()
+	}
+	onu := &oop.Onu{IntfId: IntfID, OnuId: onuID, SerialNumber: sn}
+	if _, err := dh.Client.DeleteOnu(context.Background(), onu); err != nil {
+		return NewErrAdapter("failed-to-delete-onu", log.Fields{
+			"device-id": dh.deviceID,
+			"onu-id":    onuID}, err).Log()
+	}
+	//clear PON resources associated with ONU
+	var onuGemData []rsrcMgr.OnuGemInfo
+	if err := dh.resourceMgr.ResourceMgrs[IntfID].GetOnuGemInfo(ctx, IntfID, &onuGemData); err != nil {
+		log.Errorw("Failed-to-get-onu-info-for-pon-port ", log.Fields{
+			"device-id":    dh.deviceID,
+			"interface-id": IntfID,
+			"error":        err})
+	}
+
+	for i, onu := range onuGemData {
+		if onu.OnuID == onuID && onu.SerialNumber == onuDevice.(*OnuDevice).serialNumber {
+			log.Debugw("onu-data ", log.Fields{"onu": onu})
+			if err := dh.clearUNIData(ctx, &onu); err != nil {
+				log.Errorw("Failed-to-clear-uni-data-for-onu", log.Fields{
+					"device-id":  dh.deviceID,
+					"onu-device": onu,
+					"error":      err})
+			}
+			// Clear flowids for gem cache.
+			for _, gem := range onu.GemPorts {
+				dh.resourceMgr.DeleteFlowIDsForGem(ctx, IntfID, gem)
+			}
+			onuGemData = append(onuGemData[:i], onuGemData[i+1:]...)
+			dh.resourceMgr.UpdateOnuGemInfo(ctx, IntfID, onuGemData)
+
+			dh.resourceMgr.FreeonuID(ctx, IntfID, []uint32{onu.OnuID})
+			break
+		}
+	}
+	dh.onus.Delete(onuKey)
+	dh.discOnus.Delete(onuDevice.(*OnuDevice).serialNumber)
+	return nil
+}
diff --git a/adaptercore/openolt.go b/adaptercore/openolt.go
index 62e34c9..657f249 100644
--- a/adaptercore/openolt.go
+++ b/adaptercore/openolt.go
@@ -376,3 +376,13 @@
 	}
 	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()
+}
diff --git a/adaptercore/openolt_flowmgr.go b/adaptercore/openolt_flowmgr.go
index 2b8855a..578861d 100644
--- a/adaptercore/openolt_flowmgr.go
+++ b/adaptercore/openolt_flowmgr.go
@@ -2229,7 +2229,8 @@
 	defer f.lockCache.Unlock()
 	onu := rsrcMgr.OnuGemInfo{OnuID: onuID, SerialNumber: serialNum, IntfID: intfID}
 	f.onuGemInfo[intfID] = append(f.onuGemInfo[intfID], onu)
-	if err := f.resourceMgr.AddOnuInfo(ctx, intfID, onu); err != nil {
+	if err := f.resourceMgr.AddOnuGemInfo(ctx, intfID, onu); err != nil {
+		// TODO: VOL-2638
 		log.Errorw("failed to add onu info", log.Fields{"onu": onu})
 		return
 	}
diff --git a/adaptercore/resourcemanager/resourcemanager.go b/adaptercore/resourcemanager/resourcemanager.go
index db5f044..7dcdbb3 100755
--- a/adaptercore/resourcemanager/resourcemanager.go
+++ b/adaptercore/resourcemanager/resourcemanager.go
@@ -1030,8 +1030,8 @@
 	return onuGemData, nil
 }
 
-// AddOnuInfo adds onu info on to the kvstore per interface
-func (RsrcMgr *OpenOltResourceMgr) AddOnuInfo(ctx context.Context, IntfID uint32, onuGem OnuGemInfo) error {
+// AddOnuGemInfo adds onu info on to the kvstore per interface
+func (RsrcMgr *OpenOltResourceMgr) AddOnuGemInfo(ctx context.Context, IntfID uint32, onuGem OnuGemInfo) error {
 	var onuGemData []OnuGemInfo
 	var err error
 
@@ -1050,19 +1050,21 @@
 	return err
 }
 
-// UpdateOnuInfo updates Onuinfo on the kvstore per interface
-func (RsrcMgr *OpenOltResourceMgr) UpdateOnuInfo(ctx context.Context, IntfID uint32, onuGem []OnuGemInfo) error {
-	var onuGemData []OnuGemInfo
-	var err error
+// UpdateOnuGemInfo updates Onuinfo on the kvstore per interface
+func (RsrcMgr *OpenOltResourceMgr) UpdateOnuGemInfo(ctx context.Context, IntfID uint32, onuGem []OnuGemInfo) error {
 
-	err = RsrcMgr.ResourceMgrs[IntfID].AddOnuGemInfo(ctx, IntfID, onuGemData)
+	// TODO: VOL-2643
+	err := RsrcMgr.ResourceMgrs[IntfID].AddOnuGemInfo(ctx, IntfID, onuGem)
 	if err != nil {
-		log.Error("Failed to add onugem to kv store")
+		log.Debugw("persistence-update-failed", log.Fields{
+			"interface-id": IntfID,
+			"gem-info":     onuGem,
+			"error":        err})
 		return err
 	}
 
 	log.Debugw("updated onugeminfo", log.Fields{"intf": IntfID, "onugem": onuGem})
-	return err
+	return nil
 }
 
 // AddUniPortToOnuInfo adds uni port to the onuinfo kvstore. check if the uni is already present if not update the kv store.