bug fix: portsMap key is PortID
diff --git a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
index 6659db6..17566bc 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/topology/Topology.java
@@ -80,7 +80,7 @@
      * @return the port if found, otherwise null.
      */
     public Integer getPort(int portId) {
-	return portsMap.get(nodeId);
+	return portsMap.get(portId);
     }
 
     /**