diff --git a/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/AnnotationsTranslator.java b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/AnnotationsTranslator.java
new file mode 100644
index 0000000..0b8cb03
--- /dev/null
+++ b/incubator/protobuf/models/src/main/java/org/onosproject/incubator/protobuf/models/net/AnnotationsTranslator.java
@@ -0,0 +1,71 @@
+/*
+ * 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;
+
+import org.onosproject.net.Annotations;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.SparseAnnotations;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * gRPC message conversion related utilities for annotations service.
+ */
+public final class AnnotationsTranslator {
+
+    private static final Logger log = LoggerFactory.getLogger(AnnotationsTranslator.class);
+
+    /**
+     * 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;
+    }
+
+    /**
+     * 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 AnnotationsTranslator() {}
+}