diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/ClientCapability.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/ClientCapability.java
index e2b5092..e9cafef 100644
--- a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/ClientCapability.java
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/ClientCapability.java
@@ -26,6 +26,8 @@
     private boolean pceccCapability;
     private boolean statefulPceCapability;
     private boolean pcInstantiationCapability;
+    private boolean labelStackCapability;
+    private boolean srCapability;
 
     /**
      * Creates new instance of client capability.
@@ -33,11 +35,34 @@
      * @param pceccCapability represents PCECC capability
      * @param statefulPceCapability represents stateful PCE capability
      * @param pcInstantiationCapability represents PC initiation capability
+     * @param labelStackCapability represents S bit is set in PCECC capability
+     * @param srCapability represents SR capability
      */
-    public ClientCapability(boolean pceccCapability, boolean statefulPceCapability, boolean pcInstantiationCapability) {
+    public ClientCapability(boolean pceccCapability, boolean statefulPceCapability, boolean pcInstantiationCapability,
+            boolean labelStackCapability, boolean srCapability) {
         this.pceccCapability = pceccCapability;
         this.statefulPceCapability = statefulPceCapability;
         this.pcInstantiationCapability = pcInstantiationCapability;
+        this.labelStackCapability = labelStackCapability;
+        this.srCapability = srCapability;
+    }
+
+    /**
+     * Obtains label stack capability.
+     *
+     * @return true if client supports PCECC capability with S bit set otherwise false
+     */
+    public boolean labelStackCapability() {
+        return labelStackCapability;
+    }
+
+    /**
+     * Obtains segment routing capability.
+     *
+     * @return true if client supports SR capability otherwise false
+     */
+    public boolean srCapability() {
+        return srCapability;
     }
 
     /**
@@ -69,7 +94,8 @@
 
     @Override
     public int hashCode() {
-        return Objects.hash(pceccCapability, statefulPceCapability, pcInstantiationCapability);
+        return Objects.hash(pceccCapability, statefulPceCapability, pcInstantiationCapability, labelStackCapability,
+                srCapability);
     }
 
     @Override
@@ -81,7 +107,9 @@
             ClientCapability other = (ClientCapability) obj;
             return Objects.equals(pceccCapability, other.pceccCapability)
                     && Objects.equals(statefulPceCapability, other.statefulPceCapability)
-                    && Objects.equals(pcInstantiationCapability, other.pcInstantiationCapability);
+                    && Objects.equals(pcInstantiationCapability, other.pcInstantiationCapability)
+                    && Objects.equals(labelStackCapability, other.labelStackCapability)
+                    && Objects.equals(srCapability, other.srCapability);
         }
         return false;
     }
@@ -92,6 +120,8 @@
                 .add("pceccCapability", pceccCapability)
                 .add("statefulPceCapability", statefulPceCapability)
                 .add("pcInstantiationCapability", pcInstantiationCapability)
+                .add("labelStackCapability", labelStackCapability)
+                .add("srCapability", srCapability)
                 .toString();
     }
 }
\ No newline at end of file
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClient.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClient.java
index afeeae8..6ab804c 100644
--- a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClient.java
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClient.java
@@ -135,4 +135,18 @@
      * @return capability supported by client
      */
     ClientCapability capability();
+
+    /**
+     * Adds PCEP device when session is successfully established.
+     *
+     * @param pc PCEP client details
+     */
+    void addNode(PcepClient pc);
+
+    /**
+     * Removes PCEP device when session is disconnected.
+     *
+     * @param pccId PCEP client ID
+     */
+    void deleteNode(PccId pccId);
 }
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
index befc3f0..fff6759 100644
--- a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepClientController.java
@@ -57,7 +57,7 @@
     void removeListener(PcepClientListener listener);
 
     /**
-     * Register a listener for OF msg events.
+     * Register a listener for PCEP msg events.
      *
      * @param listener the listener to notify
      */
@@ -71,6 +71,20 @@
     void removeEventListener(PcepEventListener listener);
 
     /**
+     * Register a listener for PCEP msg events[carrying node descriptor details].
+     *
+     * @param listener the listener to notify
+     */
+    void addNodeListener(PcepNodeListener listener);
+
+    /**
+     * Unregister a listener.
+     *
+     * @param listener the listener to be unregistered
+     */
+    void removeNodeListener(PcepNodeListener listener);
+
+    /**
      * Send a message to a particular pcc client.
      *
      * @param pccId the id of the client to send message.
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepNodeListener.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepNodeListener.java
new file mode 100644
index 0000000..a02a744
--- /dev/null
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/PcepNodeListener.java
@@ -0,0 +1,36 @@
+/*
+ * 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.pcep.controller;
+
+/**
+ * Notifies providers about PCEP node events.
+ */
+public interface PcepNodeListener {
+
+    /**
+     * Notifies that the node was added.
+     *
+     * @param pc PCEP client details
+     */
+    void addNode(PcepClient pc);
+
+    /**
+     * Notifies that the node was removed.
+     *
+     * @param pccId PCEP client ID
+     */
+    void deleteNode(PccId pccId);
+}
diff --git a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/driver/PcepAgent.java b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/driver/PcepAgent.java
index 2dc3e75..de95962 100755
--- a/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/driver/PcepAgent.java
+++ b/protocols/pcep/api/src/main/java/org/onosproject/pcep/controller/driver/PcepAgent.java
@@ -60,4 +60,17 @@
      */
     void processPcepMessage(PccId pccId, PcepMessage m);
 
+    /**
+     * Adds PCEP device when session is successfully established.
+     *
+     * @param pc PCEP client details
+     */
+    void addNode(PcepClient pc);
+
+    /**
+     * Removes PCEP device when session is disconnected.
+     *
+     * @param pccId PCEP client ID
+     */
+    void deleteNode(PccId pccId);
 }