diff --git a/core/api/src/main/java/org/onosproject/net/optical/OduCltPort.java b/core/api/src/main/java/org/onosproject/net/optical/OduCltPort.java
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+++ b/core/api/src/main/java/org/onosproject/net/optical/OduCltPort.java
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+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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.net.optical;
+
+import org.onosproject.net.CltSignalType;
+import org.onosproject.net.Port;
+
+import com.google.common.annotations.Beta;
+
+/**
+ * ODU client port (Optical channel Data Unit).
+ * Also referred to as a T-port or wide band port.
+ * See ITU G.709 "Interfaces for the Optical Transport Network (OTN)"
+ */
+@Beta
+public interface OduCltPort extends Port {
+
+    /**
+     * Returns ODU client signal type.
+     *
+     * @return ODU client signal type
+     */
+    CltSignalType signalType();
+}