diff --git a/rw_core/core/device/manager_state_callback.go b/rw_core/core/device/manager_state_callback.go
new file mode 100644
index 0000000..6bd42eb
--- /dev/null
+++ b/rw_core/core/device/manager_state_callback.go
@@ -0,0 +1,159 @@
+/*
+ * Copyright 2021-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 device
+
+import (
+	"context"
+
+	"github.com/opencord/voltha-lib-go/v7/pkg/log"
+	"github.com/opencord/voltha-protos/v5/go/core"
+	"github.com/opencord/voltha-protos/v5/go/voltha"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+)
+
+//
+//CreateLogicalDevice creates logical device in core
+func (dMgr *Manager) CreateLogicalDevice(ctx context.Context, cDevice *voltha.Device) error {
+	logger.Info(ctx, "create-logical-device")
+	// Verify whether the logical device has already been created
+	if cDevice.ParentId != "" {
+		logger.Debugw(ctx, "parent-device-already-exist", log.Fields{"device-id": cDevice.Id, "logical-device-id": cDevice.Id})
+		return nil
+	}
+	var err error
+	if _, err = dMgr.logicalDeviceMgr.createLogicalDevice(ctx, cDevice); err != nil {
+		logger.Warnw(ctx, "create-logical-device-error", log.Fields{"device": cDevice})
+		return err
+	}
+	return nil
+}
+
+// DeleteLogicalDevice deletes logical device from core
+func (dMgr *Manager) DeleteLogicalDevice(ctx context.Context, cDevice *voltha.Device) error {
+	logger.Info(ctx, "delete-logical-device")
+	var err error
+	if err = dMgr.logicalDeviceMgr.deleteLogicalDevice(ctx, cDevice); err != nil {
+		logger.Warnw(ctx, "delete-logical-device-error", log.Fields{"device-id": cDevice.Id})
+		return err
+	}
+	// Remove the logical device Id from the parent device
+	logicalID := ""
+	dMgr.UpdateDeviceAttribute(ctx, cDevice.Id, "ParentId", logicalID)
+	return nil
+}
+
+// DeleteLogicalPorts removes the logical ports associated with that deviceId
+func (dMgr *Manager) DeleteLogicalPorts(ctx context.Context, cDevice *voltha.Device) error {
+	logger.Debugw(ctx, "delete-all-logical-ports", log.Fields{"device-id": cDevice.Id})
+	if err := dMgr.logicalDeviceMgr.deleteLogicalPorts(ctx, cDevice.Id); err != nil {
+		// Just log the error.   The logical device or port may already have been deleted before this callback is invoked.
+		logger.Warnw(ctx, "delete-logical-ports-error", log.Fields{"device-id": cDevice.Id, "error": err})
+	}
+	return nil
+}
+
+// SetupUNILogicalPorts creates UNI ports on the logical device that represents a child UNI interface
+func (dMgr *Manager) SetupUNILogicalPorts(ctx context.Context, cDevice *voltha.Device) error {
+	logger.Info(ctx, "setup-uni-logical-ports")
+	cDevicePorts, err := dMgr.listDevicePorts(ctx, cDevice.Id)
+	if err != nil {
+		return err
+	}
+	if err := dMgr.logicalDeviceMgr.setupUNILogicalPorts(ctx, cDevice, cDevicePorts); err != nil {
+		logger.Warnw(ctx, "setup-uni-logical-ports-error", log.Fields{"device": cDevice, "err": err})
+		return err
+	}
+	return nil
+}
+
+// RunPostDeviceDelete removes any reference of this device
+func (dMgr *Manager) RunPostDeviceDelete(ctx context.Context, cDevice *voltha.Device) error {
+	logger.Infow(ctx, "run-post-device-delete", log.Fields{"device-id": cDevice.Id})
+	dMgr.stopManagingDevice(ctx, cDevice.Id)
+	return nil
+}
+
+//DeleteAllLogicalPorts is invoked as a callback when the parent device's connection status moves to UNREACHABLE
+func (dMgr *Manager) DeleteAllLogicalPorts(ctx context.Context, parentDevice *voltha.Device) error {
+	logger.Debugw(ctx, "delete-all-logical-ports", log.Fields{"parent-device-id": parentDevice.Id})
+	if err := dMgr.logicalDeviceMgr.deleteAllLogicalPorts(ctx, parentDevice); err != nil {
+		// Just log error as logical device may already have been deleted
+		logger.Warnw(ctx, "delete-all-logical-ports-fail", log.Fields{"parent-device-id": parentDevice.Id, "error": err})
+	}
+	return nil
+}
+
+//DeleteAllChildDevices is invoked as a callback when the parent device is deleted
+func (dMgr *Manager) DeleteAllChildDevices(ctx context.Context, parentCurrDevice *voltha.Device) error {
+	logger.Debugw(ctx, "delete-all-child-devices", log.Fields{"parent-device-id": parentCurrDevice.Id})
+	force := false
+	// Get the parent device Transient state, if its FORCE_DELETED(go for force delete for child devices)
+	// So in cases when this handler is getting called other than DELETE operation, no force option would be used.
+	agent := dMgr.getDeviceAgent(ctx, parentCurrDevice.Id)
+	if agent == nil {
+		return status.Errorf(codes.NotFound, "%s", parentCurrDevice.Id)
+	}
+
+	force = agent.getTransientState() == core.DeviceTransientState_FORCE_DELETING
+
+	ports, _ := dMgr.listDevicePorts(ctx, parentCurrDevice.Id)
+	for childDeviceID := range dMgr.getAllChildDeviceIds(ctx, ports) {
+		if agent := dMgr.getDeviceAgent(ctx, childDeviceID); agent != nil {
+			logger.Debugw(ctx, "invoking-delete-device", log.Fields{"device-id": childDeviceID, "force-delete": force})
+			if force {
+				if err := agent.deleteDeviceForce(ctx); err != nil {
+					logger.Warnw(ctx, "failure-delete-device-force", log.Fields{"device-id": childDeviceID,
+						"error": err.Error()})
+				}
+			} else {
+				if err := agent.deleteDevice(ctx); err != nil {
+					logger.Warnw(ctx, "failure-delete-device", log.Fields{"device-id": childDeviceID,
+						"error": err.Error()})
+				}
+			}
+			// No further action is required here.  The deleteDevice will change the device state where the resulting
+			// callback will take care of cleaning the child device agent.
+		}
+	}
+	return nil
+}
+
+//DeleteAllDeviceFlows is invoked as a callback when the parent device's connection status moves to UNREACHABLE
+func (dMgr *Manager) DeleteAllDeviceFlows(ctx context.Context, parentDevice *voltha.Device) error {
+	logger.Debugw(ctx, "delete-all-device-flows", log.Fields{"parent-device-id": parentDevice.Id})
+	if agent := dMgr.getDeviceAgent(ctx, parentDevice.Id); agent != nil {
+		if err := agent.deleteAllFlows(ctx); err != nil {
+			logger.Errorw(ctx, "error-deleting-all-device-flows", log.Fields{"parent-device-id": parentDevice.Id})
+			return err
+		}
+		return nil
+	}
+	return status.Errorf(codes.NotFound, "%s", parentDevice.Id)
+}
+
+// ChildDeviceLost  calls parent adapter to delete child device and all its references
+func (dMgr *Manager) ChildDeviceLost(ctx context.Context, curr *voltha.Device) error {
+	logger.Debugw(ctx, "child-device-lost", log.Fields{"child-device-id": curr.Id, "parent-device-id": curr.ParentId})
+	if parentAgent := dMgr.getDeviceAgent(ctx, curr.ParentId); parentAgent != nil {
+		if err := parentAgent.ChildDeviceLost(ctx, curr); err != nil {
+			// Just log the message and let the remaining pipeline proceed.
+			logger.Warnw(ctx, "childDeviceLost", log.Fields{"child-device-id": curr.Id, "parent-device-id": curr.ParentId, "error": err})
+		}
+	}
+	// Do not return an error as parent device may also have been deleted.  Let the remaining pipeline proceed.
+	return nil
+}