diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/GrpcNbDeviceServiceUtil.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/GrpcNbDeviceServiceUtil.java
deleted file mode 100644
index 4b84a1a..0000000
--- a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/GrpcNbDeviceServiceUtil.java
+++ /dev/null
@@ -1,389 +0,0 @@
-/*
- * Copyright 2017-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 org.onosproject.incubator.protobuf.models;
-
-import org.onlab.packet.ChassisId;
-import org.onosproject.grpc.net.device.models.DeviceDescriptionProtoOuterClass;
-import org.onosproject.grpc.net.device.models.DeviceDescriptionProtoOuterClass.DeviceDescriptionProto;
-import org.onosproject.grpc.net.device.models.DeviceEnumsProto.DeviceTypeProto;
-import org.onosproject.grpc.net.device.models.DeviceEnumsProto.MastershipRoleProto;
-import org.onosproject.grpc.net.device.models.PortDescriptionProtoOuterClass.PortDescriptionProto;
-import org.onosproject.grpc.net.device.models.PortEnumsProto;
-
-import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass;
-import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass.PortStatisticsProto;
-import org.onosproject.net.Annotations;
-import org.onosproject.net.DefaultAnnotations;
-import org.onosproject.net.Device.Type;
-import org.onosproject.net.MastershipRole;
-import org.onosproject.net.Port;
-import org.onosproject.net.PortNumber;
-import org.onosproject.net.SparseAnnotations;
-import org.onosproject.net.device.DefaultDeviceDescription;
-import org.onosproject.net.device.DefaultPortDescription;
-import org.onosproject.net.device.DefaultPortStatistics;
-import org.onosproject.net.device.DeviceDescription;
-import org.onosproject.net.device.PortDescription;
-import org.onosproject.net.device.PortStatistics;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import java.net.URI;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * gRPC message conversion related utilities for device service.
- */
-public final class GrpcNbDeviceServiceUtil {
-
-    private static final Logger log = LoggerFactory.getLogger(GrpcNbDeviceServiceUtil.class);
-
-    /**
-     * Translates gRPC enum MastershipRole to ONOS enum.
-     *
-     * @param role mastership role in gRPC enum
-     * @return equivalent in ONOS enum
-     */
-    public static MastershipRole translate(MastershipRoleProto role) {
-        switch (role) {
-            case NONE:
-                return MastershipRole.NONE;
-            case MASTER:
-                return MastershipRole.MASTER;
-            case STANDBY:
-                return MastershipRole.STANDBY;
-            case UNRECOGNIZED:
-                log.warn("Unrecognized MastershipRole gRPC message: {}", role);
-                return MastershipRole.NONE;
-            default:
-                return MastershipRole.NONE;
-        }
-    }
-
-    /**
-     * Translates ONOS enum MastershipRole to gRPC enum.
-     *
-     * @param newRole ONOS' mastership role
-     * @return equivalent in gRPC message enum
-     */
-    public static MastershipRoleProto translate(MastershipRole newRole) {
-        switch (newRole) {
-            case MASTER:
-                return MastershipRoleProto.MASTER;
-            case STANDBY:
-                return MastershipRoleProto.STANDBY;
-            case NONE:
-            default:
-                return MastershipRoleProto.NONE;
-        }
-    }
-
-
-    /**
-     * Translates gRPC DeviceDescription to {@link DeviceDescriptionProtoOuterClass}.
-     *
-     * @param deviceDescription gRPC message
-     * @return {@link DeviceDescriptionProtoOuterClass}
-     */
-    public static DeviceDescription translate(
-            DeviceDescriptionProto deviceDescription) {
-        URI uri = URI.create(deviceDescription.getDeviceUri());
-        Type type = translate(deviceDescription.getType());
-        String manufacturer = deviceDescription.getManufacturer();
-        String hwVersion = deviceDescription.getHwVersion();
-        String swVersion = deviceDescription.getSwVersion();
-        String serialNumber = deviceDescription.getSerialNumber();
-        ChassisId chassis = new ChassisId(deviceDescription.getChassisId());
-        boolean defaultAvailable = deviceDescription.getIsDefaultAvailable();
-        return new DefaultDeviceDescription(uri, type, manufacturer,
-                hwVersion, swVersion, serialNumber,
-                chassis,
-                defaultAvailable,
-                asAnnotations(deviceDescription.getAnnotationsMap()));
-    }
-
-    /**
-     * Translates {@link DeviceDescription} to gRPC DeviceDescription message.
-     *
-     * @param deviceDescription {@link DeviceDescription}
-     * @return gRPC DeviceDescription message
-     */
-    public static DeviceDescriptionProto translate(
-            DeviceDescription deviceDescription) {
-
-        return DeviceDescriptionProto.newBuilder()
-                .setDeviceUri(deviceDescription.deviceUri().toString())
-                .setType(translate(deviceDescription.type()))
-                .setManufacturer(deviceDescription.manufacturer())
-                .setHwVersion(deviceDescription.hwVersion())
-                .setSwVersion(deviceDescription.swVersion())
-                .setSerialNumber(deviceDescription.serialNumber())
-                .setChassisId(deviceDescription.chassisId().toString())
-                .setIsDefaultAvailable(deviceDescription.isDefaultAvailable())
-                .putAllAnnotations(asMap(deviceDescription.annotations()))
-                .build();
-    }
-
-
-    /**
-     * Translates gRPC DeviceType to {@link Type}.
-     *
-     * @param type      gRPC message
-     * @return  {@link Type}
-     */
-    public static Type translate(DeviceTypeProto type) {
-        switch (type) {
-            case BALANCER:
-                return Type.BALANCER;
-            case CONTROLLER:
-                return Type.CONTROLLER;
-            case FIBER_SWITCH:
-                return Type.FIBER_SWITCH;
-            case FIREWALL:
-                return Type.FIREWALL;
-            case IDS:
-                return Type.IDS;
-            case IPS:
-                return Type.IPS;
-            case MICROWAVE:
-                return Type.MICROWAVE;
-            case OTHER:
-                return Type.OTHER;
-            case OTN:
-                return Type.OTN;
-            case ROADM:
-                return Type.ROADM;
-            case ROADM_OTN:
-                return Type.ROADM_OTN;
-            case ROUTER:
-                return Type.ROUTER;
-            case SWITCH:
-                return Type.SWITCH;
-            case VIRTUAL_DEVICE:
-                return Type.VIRTUAL;
-
-            case UNRECOGNIZED:
-            default:
-                log.warn("Unexpected DeviceType: {}", type);
-                return Type.OTHER;
-        }
-    }
-
-    /**
-     * Translates {@link Type} to gRPC DeviceType.
-     *
-     * @param type {@link Type}
-     * @return  gRPC message
-     */
-    public static DeviceTypeProto translate(Type type) {
-        switch (type) {
-            case BALANCER:
-                return DeviceTypeProto.BALANCER;
-            case CONTROLLER:
-                return DeviceTypeProto.CONTROLLER;
-            case FIBER_SWITCH:
-                return DeviceTypeProto.FIBER_SWITCH;
-            case FIREWALL:
-                return DeviceTypeProto.FIREWALL;
-            case IDS:
-                return DeviceTypeProto.IDS;
-            case IPS:
-                return DeviceTypeProto.IPS;
-            case MICROWAVE:
-                return DeviceTypeProto.MICROWAVE;
-            case OTHER:
-                return DeviceTypeProto.OTHER;
-            case OTN:
-                return DeviceTypeProto.OTN;
-            case ROADM:
-                return DeviceTypeProto.ROADM;
-            case ROADM_OTN:
-                return DeviceTypeProto.ROADM_OTN;
-            case ROUTER:
-                return DeviceTypeProto.ROUTER;
-            case SWITCH:
-                return DeviceTypeProto.SWITCH;
-            case VIRTUAL:
-                return DeviceTypeProto.VIRTUAL_DEVICE;
-
-            default:
-                log.warn("Unexpected Device.Type: {}", type);
-                return DeviceTypeProto.OTHER;
-        }
-    }
-
-    /**
-     * Translates gRPC PortDescription message to {@link PortDescription}.
-     *
-     * @param portDescription gRPC message
-     * @return {@link PortDescription}
-     */
-    public static PortDescription translate(PortDescriptionProto portDescription) {
-        PortNumber number = PortNumber.fromString(portDescription.getPortNumber());
-        boolean isEnabled = portDescription.getIsEnabled();
-        Port.Type type = translate(portDescription.getType());
-        long portSpeed = portDescription.getPortSpeed();
-        SparseAnnotations annotations = asAnnotations(portDescription.getAnnotationsMap());
-        // TODO How to deal with more specific Port...
-        return new DefaultPortDescription(number, isEnabled, type, portSpeed, annotations);
-    }
-
-    /**
-     * Translates {@link PortDescription} to gRPC PortDescription message.
-     *
-     * @param portDescription {@link PortDescription}
-     * @return gRPC PortDescription message
-     */
-    public static PortDescriptionProto translate(PortDescription portDescription) {
-        return PortDescriptionProto.newBuilder()
-                .setPortNumber(portDescription.portNumber().toString())
-                .setIsEnabled(portDescription.isEnabled())
-                .setType(translate(portDescription.type()))
-                .setPortSpeed(portDescription.portSpeed())
-                .putAllAnnotations(asMap(portDescription.annotations()))
-                .build();
-    }
-
-    /**
-     * Translates gRPC PortType to {@link Port.Type}.
-     *
-     * @param type      gRPC message
-     * @return  {@link Port.Type}
-     */
-    public static Port.Type translate(PortEnumsProto.PortTypeProto type) {
-        switch (type) {
-            case COPPER:
-                return Port.Type.COPPER;
-            case FIBER:
-                return Port.Type.FIBER;
-            case OCH:
-                return Port.Type.OCH;
-            case ODUCLT:
-                return Port.Type.ODUCLT;
-            case OMS:
-                return Port.Type.OMS;
-            case PACKET:
-                return Port.Type.PACKET;
-            case VIRTUAL_PORT:
-                return Port.Type.VIRTUAL;
-
-            case UNRECOGNIZED:
-            default:
-                log.warn("Unexpected PortType: {}", type);
-                return Port.Type.COPPER;
-        }
-    }
-
-    /**
-     * Translates {@link Port.Type} to gRPC PortType.
-     *
-     * @param type      {@link Port.Type}
-     * @return  gRPC message
-     */
-    public static PortEnumsProto.PortTypeProto translate(Port.Type type) {
-        switch (type) {
-            case COPPER:
-                return PortEnumsProto.PortTypeProto.COPPER;
-            case FIBER:
-                return PortEnumsProto.PortTypeProto.FIBER;
-            case OCH:
-                return PortEnumsProto.PortTypeProto.OCH;
-            case ODUCLT:
-                return PortEnumsProto.PortTypeProto.ODUCLT;
-            case OMS:
-                return PortEnumsProto.PortTypeProto.OMS;
-            case PACKET:
-                return PortEnumsProto.PortTypeProto.PACKET;
-            case VIRTUAL:
-                return PortEnumsProto.PortTypeProto.VIRTUAL_PORT;
-
-            default:
-                log.warn("Unexpected Port.Type: {}", type);
-                return PortEnumsProto.PortTypeProto.COPPER;
-        }
-    }
-
-    /**
-     * Translates gRPC PortStatistics message to {@link PortStatisticsProtoOuterClass}.
-     *
-     * @param portStatistics gRPC PortStatistics message
-     * @return {@link PortStatisticsProtoOuterClass}
-     */
-    public static PortStatistics translate(PortStatisticsProto portStatistics) {
-        // TODO implement adding missing fields
-        return DefaultPortStatistics.builder()
-                .setPort(portStatistics.getPort())
-                .setPacketsReceived(portStatistics.getPacketsReceived())
-                .setPacketsSent(portStatistics.getPacketsSent())
-                .build();
-    }
-
-    /**
-     * Translates {@link PortStatistics} to gRPC PortStatistics message.
-     *
-     * @param portStatistics {@link PortStatistics}
-     * @return gRPC PortStatistics message
-     */
-    public static PortStatisticsProto translate(PortStatistics portStatistics) {
-        // TODO implement adding missing fields
-        return PortStatisticsProto.newBuilder()
-                .setPort(portStatistics.port())
-                .setPacketsReceived(portStatistics.packetsReceived())
-                .setPacketsSent(portStatistics.packetsSent())
-                .build();
-    }
-
-    // may be this can be moved to Annotation itself or AnnotationsUtils
-    /**
-     * Converts Annotations to Map of Strings.
-     *
-     * @param annotations {@link Annotations}
-     * @return Map of annotation key and values
-     */
-    public static Map<String, String> asMap(Annotations annotations) {
-        if (annotations instanceof DefaultAnnotations) {
-            return ((DefaultAnnotations) annotations).asMap();
-        }
-        Map<String, String> map = new HashMap<>();
-        annotations.keys()
-                .forEach(k -> map.put(k, annotations.value(k)));
-
-        return map;
-    }
-
-    // may be this can be moved to Annotation itself or AnnotationsUtils
-    /**
-     * Converts Map of Strings to {@link SparseAnnotations}.
-     *
-     * @param annotations Map of annotation key and values
-     * @return {@link SparseAnnotations}
-     */
-    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
-        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
-        annotations.entrySet().forEach(e -> {
-            if (e.getValue() != null) {
-                builder.set(e.getKey(), e.getValue());
-            } else {
-                builder.remove(e.getKey());
-            }
-        });
-        return builder.build();
-    }
-
-    // Utility class not intended for instantiation.
-    private GrpcNbDeviceServiceUtil() {}
-}
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/ProtobufUtils.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/ProtobufUtils.java
deleted file mode 100644
index 14df91c..0000000
--- a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/ProtobufUtils.java
+++ /dev/null
@@ -1,387 +0,0 @@
-/*
- * Copyright 2017-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 org.onosproject.incubator.protobuf.models;
-
-import java.net.URI;
-import java.util.HashMap;
-import java.util.Map;
-
-import org.onlab.packet.ChassisId;
-import org.onosproject.grpc.net.device.models.DeviceDescriptionProtoOuterClass.DeviceDescriptionProto;
-import org.onosproject.grpc.net.device.models.DeviceEnumsProto.MastershipRoleProto;
-import org.onosproject.grpc.net.device.models.PortDescriptionProtoOuterClass.PortDescriptionProto;
-import org.onosproject.grpc.net.device.models.PortEnumsProto.PortTypeProto;
-import org.onosproject.grpc.net.device.models.DeviceEnumsProto.DeviceTypeProto;
-import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass.PortStatisticsProto;
-import org.onosproject.net.Annotations;
-import org.onosproject.net.DefaultAnnotations;
-import org.onosproject.net.Device;
-import org.onosproject.net.MastershipRole;
-import org.onosproject.net.Port;
-import org.onosproject.net.Port.Type;
-import org.onosproject.net.PortNumber;
-import org.onosproject.net.SparseAnnotations;
-import org.onosproject.net.device.DefaultDeviceDescription;
-import org.onosproject.net.device.DefaultPortDescription;
-import org.onosproject.net.device.DefaultPortStatistics;
-import org.onosproject.net.device.DeviceDescription;
-import org.onosproject.net.device.PortDescription;
-import org.onosproject.net.device.PortStatistics;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.google.common.annotations.Beta;
-
-/**
- * gRPC message conversion related utilities.
- */
-@Beta
-public final class ProtobufUtils {
-
-    private static final Logger log = LoggerFactory.getLogger(ProtobufUtils.class);
-
-    /**
-     * Translates gRPC enum MastershipRoleProto to ONOS enum.
-     *
-     * @param role mastership role in gRPC enum
-     * @return equivalent ONOS enum
-     */
-    public static MastershipRole translate(MastershipRoleProto role) {
-        switch (role) {
-            case NONE:
-                return MastershipRole.NONE;
-            case MASTER:
-                return MastershipRole.MASTER;
-            case STANDBY:
-                return MastershipRole.STANDBY;
-            case UNRECOGNIZED:
-                log.warn("Unrecognized MastershipRole gRPC message: {}", role);
-                return MastershipRole.NONE;
-            default:
-                return MastershipRole.NONE;
-        }
-    }
-
-    /**
-     * Translates ONOS enum MastershipRole to gRPC enum.
-     *
-     * @param newRole ONOS' mastership role
-     * @return equivalent gRPC message enum
-     */
-    public static MastershipRoleProto translate(MastershipRole newRole) {
-        switch (newRole) {
-            case MASTER:
-                return MastershipRoleProto.MASTER;
-            case STANDBY:
-                return MastershipRoleProto.STANDBY;
-            case NONE:
-            default:
-                return MastershipRoleProto.NONE;
-        }
-    }
-
-    /**
-     * Translates gRPC DeviceDescriptionProto to {@link DeviceDescription}.
-     *
-     * @param devDescProto device description protobuf message
-     * @return {@link DeviceDescription}
-     */
-    public static DeviceDescription translate(
-            DeviceDescriptionProto devDescProto) {
-        URI uri = URI.create(devDescProto.getDeviceUri());
-        Device.Type type = translate(devDescProto.getType());
-        String manufacturer = devDescProto.getManufacturer();
-        String hwVersion = devDescProto.getHwVersion();
-        String swVersion = devDescProto.getSwVersion();
-        String serialNumber = devDescProto.getSerialNumber();
-        ChassisId chassis = new ChassisId(devDescProto.getChassisId());
-        boolean defaultAvailable = devDescProto.getIsDefaultAvailable();
-        return new DefaultDeviceDescription(uri, type, manufacturer,
-                                            hwVersion, swVersion, serialNumber,
-                                            chassis,
-                                            defaultAvailable,
-                                            asAnnotations(devDescProto.getAnnotationsMap()));
-    }
-
-    /**
-     * Translates {@link DeviceDescription} to gRPC DeviceDescriptionProto message.
-     *
-     * @param deviceDescription {@link DeviceDescription}
-     * @return gRPC DeviceDescriptionProto message
-     */
-    public static DeviceDescriptionProto translate(
-            DeviceDescription deviceDescription) {
-
-        return DeviceDescriptionProto.newBuilder()
-                .setDeviceUri(deviceDescription.deviceUri().toString())
-                .setType(translate(deviceDescription.type()))
-                .setManufacturer(deviceDescription.manufacturer())
-                .setHwVersion(deviceDescription.hwVersion())
-                .setSwVersion(deviceDescription.swVersion())
-                .setSerialNumber(deviceDescription.serialNumber())
-                .setChassisId(deviceDescription.chassisId().toString())
-                .setIsDefaultAvailable(deviceDescription.isDefaultAvailable())
-                .putAllAnnotations(asMap(deviceDescription.annotations()))
-                .build();
-    }
-
-    /**
-     * Translates gRPC DeviceTypeProto to {@link Device.Type}.
-     *
-     * @param type      gRPC message
-     * @return  {@link Device.Type}
-     */
-    public static Device.Type translate(DeviceTypeProto type) {
-        switch (type) {
-            case BALANCER:
-                return Device.Type.BALANCER;
-            case CONTROLLER:
-                return Device.Type.CONTROLLER;
-            case FIBER_SWITCH:
-                return Device.Type.FIBER_SWITCH;
-            case FIREWALL:
-                return Device.Type.FIREWALL;
-            case IDS:
-                return Device.Type.IDS;
-            case IPS:
-                return Device.Type.IPS;
-            case MICROWAVE:
-                return Device.Type.MICROWAVE;
-            case OTHER:
-                return Device.Type.OTHER;
-            case OTN:
-                return Device.Type.OTN;
-            case ROADM:
-                return Device.Type.ROADM;
-            case ROADM_OTN:
-                return Device.Type.ROADM_OTN;
-            case ROUTER:
-                return Device.Type.ROUTER;
-            case SWITCH:
-                return Device.Type.SWITCH;
-            case VIRTUAL_DEVICE:
-                return Device.Type.VIRTUAL;
-
-            case UNRECOGNIZED:
-            default:
-                log.warn("Unexpected DeviceType: {}", type);
-                return Device.Type.OTHER;
-        }
-    }
-
-    /**
-     * Translates {@link Type} to gRPC DeviceTypeProto.
-     *
-     * @param type {@link Type}
-     * @return  gRPC message
-     */
-    public static DeviceTypeProto translate(Device.Type type) {
-        switch (type) {
-            case BALANCER:
-                return DeviceTypeProto.BALANCER;
-            case CONTROLLER:
-                return DeviceTypeProto.CONTROLLER;
-            case FIBER_SWITCH:
-                return DeviceTypeProto.FIBER_SWITCH;
-            case FIREWALL:
-                return DeviceTypeProto.FIREWALL;
-            case IDS:
-                return DeviceTypeProto.IDS;
-            case IPS:
-                return DeviceTypeProto.IPS;
-            case MICROWAVE:
-                return DeviceTypeProto.MICROWAVE;
-            case OTHER:
-                return DeviceTypeProto.OTHER;
-            case OTN:
-                return DeviceTypeProto.OTN;
-            case ROADM:
-                return DeviceTypeProto.ROADM;
-            case ROADM_OTN:
-                return DeviceTypeProto.ROADM_OTN;
-            case ROUTER:
-                return DeviceTypeProto.ROUTER;
-            case SWITCH:
-                return DeviceTypeProto.SWITCH;
-            case VIRTUAL:
-                return DeviceTypeProto.VIRTUAL_DEVICE;
-
-            default:
-                log.warn("Unexpected Device.Type: {}", type);
-                return DeviceTypeProto.OTHER;
-        }
-    }
-
-    /**
-     * Translates gRPC PortDescriptionProto message to {@link PortDescription}.
-     *
-     * @param portDescription gRPC message
-     * @return {@link PortDescription}
-     */
-    public static PortDescription translate(PortDescriptionProto portDescription) {
-        PortNumber number = PortNumber.fromString(portDescription.getPortNumber());
-        boolean isEnabled = portDescription.getIsEnabled();
-        Port.Type type = translate(portDescription.getType());
-        long portSpeed = portDescription.getPortSpeed();
-        SparseAnnotations annotations = asAnnotations(portDescription.getAnnotationsMap());
-        return new DefaultPortDescription(number, isEnabled, type, portSpeed, annotations);
-    }
-
-    /**
-     * Translates {@link PortDescription} to gRPC PortDescriptionProto message.
-     *
-     * @param portDescription {@link PortDescription}
-     * @return gRPC PortDescriptionProto message
-     */
-    public static PortDescriptionProto translate(PortDescription portDescription) {
-        return PortDescriptionProto.newBuilder()
-                .setPortNumber(portDescription.portNumber().toString())
-                .setIsEnabled(portDescription.isEnabled())
-                .setType(translate(portDescription.type()))
-                .setPortSpeed(portDescription.portSpeed())
-                .putAllAnnotations(asMap(portDescription.annotations()))
-                .build();
-    }
-
-    /**
-     * Translates gRPC PortTypeProto to {@link Port.Type}.
-     *
-     * @param type      gRPC message
-     * @return  {@link Port.Type}
-     */
-    public static Port.Type translate(PortTypeProto type) {
-        switch (type) {
-            case COPPER:
-                return Type.COPPER;
-            case FIBER:
-                return Type.FIBER;
-            case OCH:
-                return Type.OCH;
-            case ODUCLT:
-                return Type.ODUCLT;
-            case OMS:
-                return Type.OMS;
-            case PACKET:
-                return Type.PACKET;
-            case VIRTUAL_PORT:
-                return Type.VIRTUAL;
-
-            case UNRECOGNIZED:
-            default:
-                log.warn("Unexpected PortType: {}", type);
-                return Type.COPPER;
-        }
-    }
-
-    /**
-     * Translates {@link Port.Type} to gRPC PortType.
-     *
-     * @param type      {@link org.onosproject.net.Port.Type}
-     * @return  gRPC message
-     */
-    public static PortTypeProto translate(Port.Type type) {
-        switch (type) {
-            case COPPER:
-                return PortTypeProto.COPPER;
-            case FIBER:
-                return PortTypeProto.FIBER;
-            case OCH:
-                return PortTypeProto.OCH;
-            case ODUCLT:
-                return PortTypeProto.ODUCLT;
-            case OMS:
-                return PortTypeProto.OMS;
-            case PACKET:
-                return PortTypeProto.PACKET;
-            case VIRTUAL:
-                return PortTypeProto.VIRTUAL_PORT;
-
-            default:
-                log.warn("Unexpected Port.Type: {}", type);
-                return PortTypeProto.COPPER;
-        }
-    }
-
-    /**
-     * Translates gRPC PortStatistics message to {@link PortStatistics}.
-     *
-     * @param portStatistics gRPC PortStatistics message
-     * @return {@link PortStatistics}
-     */
-    public static PortStatistics translate(PortStatisticsProto portStatistics) {
-        // TODO implement adding missing fields
-        return DefaultPortStatistics.builder()
-                .setPort(portStatistics.getPort())
-                .setPacketsReceived(portStatistics.getPacketsReceived())
-                .setPacketsSent(portStatistics.getPacketsSent())
-                .build();
-    }
-
-    /**
-     * Translates {@link PortStatistics} to gRPC PortStatistics message.
-     *
-     * @param portStatistics {@link PortStatistics}
-     * @return gRPC PortStatistics message
-     */
-    public static PortStatisticsProto translate(PortStatistics portStatistics) {
-        // TODO implement adding missing fields
-        return PortStatisticsProto.newBuilder()
-                .setPort(portStatistics.port())
-                .setPacketsReceived(portStatistics.packetsReceived())
-                .setPacketsSent(portStatistics.packetsSent())
-                .build();
-    }
-
-    // may be this can be moved to Annotation itself or AnnotationsUtils
-    /**
-     * Converts Annotations to Map of Strings.
-     *
-     * @param annotations {@link Annotations}
-     * @return Map of annotation key and values
-     */
-    public static Map<String, String> asMap(Annotations annotations) {
-        if (annotations instanceof DefaultAnnotations) {
-            return ((DefaultAnnotations) annotations).asMap();
-        }
-        Map<String, String> map = new HashMap<>();
-        annotations.keys()
-                .forEach(k -> map.put(k, annotations.value(k)));
-
-        return map;
-    }
-
-    // may be this can be moved to Annotation itself or AnnotationsUtils
-    /**
-     * Converts Map of Strings to {@link SparseAnnotations}.
-     *
-     * @param annotations Map of annotation key and values
-     * @return {@link SparseAnnotations}
-     */
-    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
-        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
-        annotations.entrySet().forEach(e -> {
-            if (e.getValue() != null) {
-                builder.set(e.getKey(), e.getValue());
-            } else {
-                builder.remove(e.getKey());
-            }
-        });
-        return builder.build();
-    }
-
-    // Utility class not intended for instantiation.
-    private ProtobufUtils() {}
-}
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/LinkProtoTranslator.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/LinkProtoTranslator.java
index 56804c7..a43e995 100644
--- a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/LinkProtoTranslator.java
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/LinkProtoTranslator.java
@@ -16,14 +16,17 @@
 package org.onosproject.incubator.protobuf.models.net;
 
 import org.onosproject.grpc.net.models.LinkProtoOuterClass;
-import org.onosproject.incubator.protobuf.models.ProtobufUtils;
 import org.onosproject.incubator.protobuf.models.net.link.LinkEnumsProtoTranslator;
 import org.onosproject.net.Annotations;
 import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DefaultAnnotations;
 import org.onosproject.net.DefaultLink;
 import org.onosproject.net.Link;
+import org.onosproject.net.SparseAnnotations;
 import org.onosproject.net.provider.ProviderId;
 
+import java.util.Map;
+
 /**
  * gRPC LinkProto message to equivalent ONOS Link conversion related utilities.
  */
@@ -44,7 +47,7 @@
         ConnectPoint src = ConnectPointProtoTranslator.translate(link.getSrc()).get();
         ConnectPoint dst = ConnectPointProtoTranslator.translate(link.getDst()).get();
         Link.Type type = LinkEnumsProtoTranslator.translate(link.getType()).get();
-        Annotations annots = ProtobufUtils.asAnnotations(link.getAnnotations());
+        Annotations annots = asAnnotations(link.getAnnotations());
         Boolean isExpected = link.getIsExpected();
         return DefaultLink.builder().state(state)
                 .annotations(annots)
@@ -56,7 +59,6 @@
                 .build();
     }
 
-
     /**
      * Translates {@link org.onosproject.net.Link} to gRPC LinkCore message.
      *
@@ -77,6 +79,25 @@
                 .build();
     }
 
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Map of Strings to {@link SparseAnnotations}.
+     *
+     * @param annotations Map of annotation key and values
+     * @return {@link SparseAnnotations}
+     */
+    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
+        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
+        annotations.entrySet().forEach(e -> {
+            if (e.getValue() != null) {
+                builder.set(e.getKey(), e.getValue());
+            } else {
+                builder.remove(e.getKey());
+            }
+        });
+        return builder.build();
+    }
+
     // Utility class not intended for instantiation.
     private LinkProtoTranslator() {}
 
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/RegionProtoTranslator.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/RegionProtoTranslator.java
index 5baea7a..16b5557 100644
--- a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/RegionProtoTranslator.java
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/RegionProtoTranslator.java
@@ -15,7 +15,6 @@
  */
 package org.onosproject.incubator.protobuf.models.net;
 import com.google.common.base.Strings;
-import org.onosproject.incubator.protobuf.models.ProtobufUtils;
 import org.onosproject.incubator.protobuf.models.net.region.RegionEnumsProtoTranslator;
 
 
@@ -23,6 +22,8 @@
 import org.onosproject.cluster.NodeId;
 import org.onosproject.grpc.net.models.RegionProtoOuterClass;
 import org.onosproject.net.Annotations;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.SparseAnnotations;
 import org.onosproject.net.region.DefaultRegion;
 import org.onosproject.net.region.Region;
 import org.onosproject.net.region.RegionId;
@@ -30,6 +31,7 @@
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.stream.Collectors;
 
@@ -59,7 +61,7 @@
             masters.add(nodeIdSet);
         });
 
-        Annotations annots = ProtobufUtils.asAnnotations(region.getAnnotations());
+        Annotations annots = asAnnotations(region.getAnnotations());
 
         return new DefaultRegion(id, name, type, annots, masters);
     }
@@ -87,6 +89,25 @@
                 .build();
     }
 
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Map of Strings to {@link SparseAnnotations}.
+     *
+     * @param annotations Map of annotation key and values
+     * @return {@link SparseAnnotations}
+     */
+    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
+        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
+        annotations.entrySet().forEach(e -> {
+            if (e.getValue() != null) {
+                builder.set(e.getKey(), e.getValue());
+            } else {
+                builder.remove(e.getKey());
+            }
+        });
+        return builder.build();
+    }
+
     // Utility class not intended for instantiation.
     private RegionProtoTranslator() {}
 
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/DeviceProtoTranslator.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/DeviceProtoTranslator.java
new file mode 100644
index 0000000..495da82
--- /dev/null
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/DeviceProtoTranslator.java
@@ -0,0 +1,216 @@
+/*
+ * Copyright 2017-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 org.onosproject.incubator.protobuf.models.net.device;
+
+import org.onlab.packet.ChassisId;
+import org.onosproject.grpc.net.device.models.DeviceDescriptionProtoOuterClass;
+import org.onosproject.grpc.net.device.models.DeviceDescriptionProtoOuterClass.DeviceDescriptionProto;
+import org.onosproject.grpc.net.device.models.DeviceEnumsProto.DeviceTypeProto;
+import org.onosproject.net.Annotations;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.Device.Type;
+import org.onosproject.net.SparseAnnotations;
+import org.onosproject.net.device.DefaultDeviceDescription;
+import org.onosproject.net.device.DeviceDescription;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.URI;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * gRPC message conversion related utilities for device service.
+ */
+public final class DeviceProtoTranslator {
+
+    private static final Logger log = LoggerFactory.getLogger(DeviceProtoTranslator.class);
+
+    /**
+     * Translates gRPC DeviceDescription to {@link DeviceDescriptionProtoOuterClass}.
+     *
+     * @param deviceDescription gRPC message
+     * @return {@link DeviceDescriptionProtoOuterClass}
+     */
+    public static DeviceDescription translate(
+            DeviceDescriptionProto deviceDescription) {
+        URI uri = URI.create(deviceDescription.getDeviceUri());
+        Type type = translate(deviceDescription.getType());
+        String manufacturer = deviceDescription.getManufacturer();
+        String hwVersion = deviceDescription.getHwVersion();
+        String swVersion = deviceDescription.getSwVersion();
+        String serialNumber = deviceDescription.getSerialNumber();
+        ChassisId chassis = new ChassisId(deviceDescription.getChassisId());
+        boolean defaultAvailable = deviceDescription.getIsDefaultAvailable();
+        return new DefaultDeviceDescription(uri, type, manufacturer,
+                hwVersion, swVersion, serialNumber,
+                chassis,
+                defaultAvailable,
+                asAnnotations(deviceDescription.getAnnotationsMap()));
+    }
+
+    /**
+     * Translates {@link DeviceDescription} to gRPC DeviceDescription message.
+     *
+     * @param deviceDescription {@link DeviceDescription}
+     * @return gRPC DeviceDescription message
+     */
+    public static DeviceDescriptionProto translate(
+            DeviceDescription deviceDescription) {
+
+        return DeviceDescriptionProto.newBuilder()
+                .setDeviceUri(deviceDescription.deviceUri().toString())
+                .setType(translate(deviceDescription.type()))
+                .setManufacturer(deviceDescription.manufacturer())
+                .setHwVersion(deviceDescription.hwVersion())
+                .setSwVersion(deviceDescription.swVersion())
+                .setSerialNumber(deviceDescription.serialNumber())
+                .setChassisId(deviceDescription.chassisId().toString())
+                .setIsDefaultAvailable(deviceDescription.isDefaultAvailable())
+                .putAllAnnotations(asMap(deviceDescription.annotations()))
+                .build();
+    }
+
+
+    /**
+     * Translates gRPC DeviceType to {@link Type}.
+     *
+     * @param type gRPC message
+     * @return {@link Type}
+     */
+    public static Type translate(DeviceTypeProto type) {
+        switch (type) {
+            case BALANCER:
+                return Type.BALANCER;
+            case CONTROLLER:
+                return Type.CONTROLLER;
+            case FIBER_SWITCH:
+                return Type.FIBER_SWITCH;
+            case FIREWALL:
+                return Type.FIREWALL;
+            case IDS:
+                return Type.IDS;
+            case IPS:
+                return Type.IPS;
+            case MICROWAVE:
+                return Type.MICROWAVE;
+            case OTHER:
+                return Type.OTHER;
+            case OTN:
+                return Type.OTN;
+            case ROADM:
+                return Type.ROADM;
+            case ROADM_OTN:
+                return Type.ROADM_OTN;
+            case ROUTER:
+                return Type.ROUTER;
+            case SWITCH:
+                return Type.SWITCH;
+            case VIRTUAL_DEVICE:
+                return Type.VIRTUAL;
+
+            case UNRECOGNIZED:
+            default:
+                log.warn("Unexpected DeviceType: {}", type);
+                return Type.OTHER;
+        }
+    }
+
+    /**
+     * Translates {@link Type} to gRPC DeviceType.
+     *
+     * @param type {@link Type}
+     * @return gRPC message
+     */
+    public static DeviceTypeProto translate(Type type) {
+        switch (type) {
+            case BALANCER:
+                return DeviceTypeProto.BALANCER;
+            case CONTROLLER:
+                return DeviceTypeProto.CONTROLLER;
+            case FIBER_SWITCH:
+                return DeviceTypeProto.FIBER_SWITCH;
+            case FIREWALL:
+                return DeviceTypeProto.FIREWALL;
+            case IDS:
+                return DeviceTypeProto.IDS;
+            case IPS:
+                return DeviceTypeProto.IPS;
+            case MICROWAVE:
+                return DeviceTypeProto.MICROWAVE;
+            case OTHER:
+                return DeviceTypeProto.OTHER;
+            case OTN:
+                return DeviceTypeProto.OTN;
+            case ROADM:
+                return DeviceTypeProto.ROADM;
+            case ROADM_OTN:
+                return DeviceTypeProto.ROADM_OTN;
+            case ROUTER:
+                return DeviceTypeProto.ROUTER;
+            case SWITCH:
+                return DeviceTypeProto.SWITCH;
+            case VIRTUAL:
+                return DeviceTypeProto.VIRTUAL_DEVICE;
+
+            default:
+                log.warn("Unexpected Device.Type: {}", type);
+                return DeviceTypeProto.OTHER;
+        }
+    }
+
+
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Annotations to Map of Strings.
+     *
+     * @param annotations {@link Annotations}
+     * @return Map of annotation key and values
+     */
+    public static Map<String, String> asMap(Annotations annotations) {
+        if (annotations instanceof DefaultAnnotations) {
+            return ((DefaultAnnotations) annotations).asMap();
+        }
+        Map<String, String> map = new HashMap<>();
+        annotations.keys()
+                .forEach(k -> map.put(k, annotations.value(k)));
+
+        return map;
+    }
+
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Map of Strings to {@link SparseAnnotations}.
+     *
+     * @param annotations Map of annotation key and values
+     * @return {@link SparseAnnotations}
+     */
+    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
+        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
+        annotations.entrySet().forEach(e -> {
+            if (e.getValue() != null) {
+                builder.set(e.getKey(), e.getValue());
+            } else {
+                builder.remove(e.getKey());
+            }
+        });
+        return builder.build();
+    }
+
+    // Utility class not intended for instantiation.
+    private DeviceProtoTranslator() {
+    }
+}
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/PortProtoTranslator.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/PortProtoTranslator.java
new file mode 100644
index 0000000..91bcd32
--- /dev/null
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/PortProtoTranslator.java
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2017-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 org.onosproject.incubator.protobuf.models.net.device;
+
+import org.onosproject.grpc.net.device.models.PortDescriptionProtoOuterClass.PortDescriptionProto;
+import org.onosproject.grpc.net.device.models.PortEnumsProto;
+import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass;
+import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass.PortStatisticsProto;
+import org.onosproject.net.Annotations;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.Port;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.SparseAnnotations;
+import org.onosproject.net.device.DefaultPortDescription;
+import org.onosproject.net.device.DefaultPortStatistics;
+import org.onosproject.net.device.PortDescription;
+import org.onosproject.net.device.PortStatistics;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * gRPC message conversion related utilities for port service.
+ */
+public final class PortProtoTranslator {
+
+    private static final Logger log = LoggerFactory.getLogger(PortProtoTranslator.class);
+
+    /**
+     * Translates gRPC PortDescription message to {@link PortDescription}.
+     *
+     * @param portDescription gRPC message
+     * @return {@link PortDescription}
+     */
+    public static PortDescription translate(PortDescriptionProto portDescription) {
+        PortNumber number = PortNumber.fromString(portDescription.getPortNumber());
+        boolean isEnabled = portDescription.getIsEnabled();
+        Port.Type type = translate(portDescription.getType());
+        long portSpeed = portDescription.getPortSpeed();
+        SparseAnnotations annotations = asAnnotations(portDescription.getAnnotationsMap());
+        // TODO How to deal with more specific Port...
+        return new DefaultPortDescription(number, isEnabled, type, portSpeed, annotations);
+    }
+
+    /**
+     * Translates {@link PortDescription} to gRPC PortDescription message.
+     *
+     * @param portDescription {@link PortDescription}
+     * @return gRPC PortDescription message
+     */
+    public static PortDescriptionProto translate(PortDescription portDescription) {
+        return PortDescriptionProto.newBuilder()
+                .setPortNumber(portDescription.portNumber().toString())
+                .setIsEnabled(portDescription.isEnabled())
+                .setType(translate(portDescription.type()))
+                .setPortSpeed(portDescription.portSpeed())
+                .putAllAnnotations(asMap(portDescription.annotations()))
+                .build();
+    }
+
+    /**
+     * Translates gRPC PortType to {@link Port.Type}.
+     *
+     * @param type      gRPC message
+     * @return  {@link Port.Type}
+     */
+    public static Port.Type translate(PortEnumsProto.PortTypeProto type) {
+        switch (type) {
+            case COPPER:
+                return Port.Type.COPPER;
+            case FIBER:
+                return Port.Type.FIBER;
+            case OCH:
+                return Port.Type.OCH;
+            case ODUCLT:
+                return Port.Type.ODUCLT;
+            case OMS:
+                return Port.Type.OMS;
+            case PACKET:
+                return Port.Type.PACKET;
+            case VIRTUAL_PORT:
+                return Port.Type.VIRTUAL;
+
+            case UNRECOGNIZED:
+            default:
+                log.warn("Unexpected PortType: {}", type);
+                return Port.Type.COPPER;
+        }
+    }
+
+    /**
+     * Translates {@link Port.Type} to gRPC PortType.
+     *
+     * @param type      {@link Port.Type}
+     * @return  gRPC message
+     */
+    public static PortEnumsProto.PortTypeProto translate(Port.Type type) {
+        switch (type) {
+            case COPPER:
+                return PortEnumsProto.PortTypeProto.COPPER;
+            case FIBER:
+                return PortEnumsProto.PortTypeProto.FIBER;
+            case OCH:
+                return PortEnumsProto.PortTypeProto.OCH;
+            case ODUCLT:
+                return PortEnumsProto.PortTypeProto.ODUCLT;
+            case OMS:
+                return PortEnumsProto.PortTypeProto.OMS;
+            case PACKET:
+                return PortEnumsProto.PortTypeProto.PACKET;
+            case VIRTUAL:
+                return PortEnumsProto.PortTypeProto.VIRTUAL_PORT;
+
+            default:
+                log.warn("Unexpected Port.Type: {}", type);
+                return PortEnumsProto.PortTypeProto.COPPER;
+        }
+    }
+
+    /**
+     * Translates gRPC PortStatistics message to {@link PortStatisticsProtoOuterClass}.
+     *
+     * @param portStatistics gRPC PortStatistics message
+     * @return {@link PortStatisticsProtoOuterClass}
+     */
+    public static PortStatistics translate(PortStatisticsProto portStatistics) {
+        // TODO implement adding missing fields
+        return DefaultPortStatistics.builder()
+                .setPort(portStatistics.getPort())
+                .setPacketsReceived(portStatistics.getPacketsReceived())
+                .setPacketsSent(portStatistics.getPacketsSent())
+                .build();
+    }
+
+    /**
+     * Translates {@link PortStatistics} to gRPC PortStatistics message.
+     *
+     * @param portStatistics {@link PortStatistics}
+     * @return gRPC PortStatistics message
+     */
+    public static PortStatisticsProto translate(PortStatistics portStatistics) {
+        // TODO implement adding missing fields
+        return PortStatisticsProto.newBuilder()
+                .setPort(portStatistics.port())
+                .setPacketsReceived(portStatistics.packetsReceived())
+                .setPacketsSent(portStatistics.packetsSent())
+                .build();
+    }
+
+
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Annotations to Map of Strings.
+     *
+     * @param annotations {@link Annotations}
+     * @return Map of annotation key and values
+     */
+    public static Map<String, String> asMap(Annotations annotations) {
+        if (annotations instanceof DefaultAnnotations) {
+            return ((DefaultAnnotations) annotations).asMap();
+        }
+        Map<String, String> map = new HashMap<>();
+        annotations.keys()
+                .forEach(k -> map.put(k, annotations.value(k)));
+
+        return map;
+    }
+
+    // may be this can be moved to Annotation itself or AnnotationsUtils
+    /**
+     * Converts Map of Strings to {@link SparseAnnotations}.
+     *
+     * @param annotations Map of annotation key and values
+     * @return {@link SparseAnnotations}
+     */
+    public static SparseAnnotations asAnnotations(Map<String, String> annotations) {
+        DefaultAnnotations.Builder builder = DefaultAnnotations.builder();
+        annotations.entrySet().forEach(e -> {
+            if (e.getValue() != null) {
+                builder.set(e.getKey(), e.getValue());
+            } else {
+                builder.remove(e.getKey());
+            }
+        });
+        return builder.build();
+    }
+
+    // Utility class not intended for instantiation.
+    private PortProtoTranslator() {}
+}
diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/package-info.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/package-info.java
similarity index 83%
rename from incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/package-info.java
rename to incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/package-info.java
index 69643cf..5239102 100644
--- a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/package-info.java
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/device/package-info.java
@@ -14,6 +14,6 @@
  * limitations under the License.
  */
 /**
- * Utilities to handle ProtoBuf version of ONOS network models.
+ * Utilities to handle ProtoBuf version of ONOS device models.
  */
-package org.onosproject.incubator.protobuf.models;
+package org.onosproject.incubator.protobuf.models.net.device;
\ No newline at end of file
diff --git a/incubator/protobuf/models/src/main/proto/net/device/DeviceEnumsProto.proto b/incubator/protobuf/models/src/main/proto/net/device/DeviceEnumsProto.proto
index d574a35..52ecc75 100644
--- a/incubator/protobuf/models/src/main/proto/net/device/DeviceEnumsProto.proto
+++ b/incubator/protobuf/models/src/main/proto/net/device/DeviceEnumsProto.proto
@@ -3,12 +3,6 @@
 
 package net.device;
 
-enum MastershipRoleProto {
-    NONE = 0;
-    MASTER = 1;
-    STANDBY = 2;
-}
-
 enum DeviceTypeProto {
     OTHER = 0;
     SWITCH = 1;
diff --git a/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbDeviceService.java b/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbDeviceService.java
index e898df4..b583800 100644
--- a/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbDeviceService.java
+++ b/incubator/protobuf/services/nb/src/main/java/org/onosproject/incubator/protobuf/services/nb/GrpcNbDeviceService.java
@@ -15,7 +15,6 @@
  */
 package org.onosproject.incubator.protobuf.services.nb;
 
-
 import com.google.common.annotations.Beta;
 import io.grpc.BindableService;
 import io.grpc.stub.StreamObserver;
@@ -27,6 +26,7 @@
 import org.onosproject.grpc.net.device.models.PortEnumsProto;
 import org.onosproject.grpc.net.device.models.PortStatisticsProtoOuterClass.PortStatisticsProto;
 import org.onosproject.grpc.nb.net.device.DeviceServiceGrpc.DeviceServiceImplBase;
+import org.onosproject.grpc.net.models.MastershipRoleProtoOuterClass;
 import org.onosproject.grpc.net.models.PortProtoOuterClass.PortProto;
 import org.onosproject.grpc.net.device.models.DeviceEnumsProto;
 import org.onosproject.protobuf.api.GrpcServiceRegistry;
@@ -35,17 +35,16 @@
 import org.onosproject.net.MastershipRole;
 import org.onosproject.net.PortNumber;
 import org.onosproject.net.device.DeviceService;
-import org.onosproject.incubator.protobuf.models.GrpcNbDeviceServiceUtil;
+import org.onosproject.incubator.protobuf.models.net.device.DeviceProtoTranslator;
 import org.slf4j.Logger;
 
 import static org.onosproject.grpc.nb.net.device.DeviceServiceNb.*;
 import static org.slf4j.LoggerFactory.getLogger;
 
-
 /**
  * A server that provides access to the methods exposed by {@link DeviceService}.
  * TODO this requires major refactoring, translation should be delegated to calls to
- * TODO{@link GrpcNbDeviceServiceUtil}.
+ * TODO{@link DeviceProtoTranslator}.
  */
 @Beta
 @Component(immediate = true)
@@ -180,8 +179,8 @@
                             StreamObserver<getRoleReply> responseObserver) {
             DeviceId deviceId = DeviceId.deviceId(request.getDeviceId());
             MastershipRole role = deviceService.getRole(deviceId);
-            DeviceEnumsProto.MastershipRoleProto mastershipRole =
-                    DeviceEnumsProto.MastershipRoleProto.valueOf(role.toString());
+            MastershipRoleProtoOuterClass.MastershipRoleProto mastershipRole =
+                    MastershipRoleProtoOuterClass.MastershipRoleProto.valueOf(role.toString());
             responseObserver.onNext(getRoleReply.newBuilder()
                     .setRole(mastershipRole).build());
             responseObserver.onCompleted();
diff --git a/incubator/protobuf/services/nb/src/main/proto/net/device/DeviceServiceNb.proto b/incubator/protobuf/services/nb/src/main/proto/net/device/DeviceServiceNb.proto
index 1b1dad5..cdf4d89 100644
--- a/incubator/protobuf/services/nb/src/main/proto/net/device/DeviceServiceNb.proto
+++ b/incubator/protobuf/services/nb/src/main/proto/net/device/DeviceServiceNb.proto
@@ -5,6 +5,7 @@
 
 import "net/DeviceProto.proto";
 import "net/device/DeviceEnumsProto.proto";
+import "net/MastershipRoleProto.proto";
 import "net/device/PortStatisticsProto.proto";
 import "net/PortProto.proto";
 import "net/ConnectPointProto.proto";
@@ -44,7 +45,7 @@
 }
 
 message getRoleReply {
-    .net.device.MastershipRoleProto role = 1;
+    .net.MastershipRoleProto role = 1;
 }
 
 message getPortsRequest {