diff --git a/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java b/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
index 1f21221..e23baf4 100644
--- a/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
+++ b/src/main/java/net/floodlightcontroller/routing/TopoRouteService.java
@@ -2,10 +2,15 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Queue;
+import java.util.Set;
 
 import net.floodlightcontroller.core.internal.SwitchStorageImpl;
 import net.floodlightcontroller.core.module.FloodlightModuleContext;
@@ -22,6 +27,8 @@
 import org.openflow.util.HexString;
 
 import com.thinkaurelius.titan.core.TitanGraph;
+import com.thinkaurelius.titan.core.TitanTransaction;
+import com.tinkerpop.blueprints.Direction;
 import com.tinkerpop.blueprints.TransactionalGraph.Conclusion;
 import com.tinkerpop.blueprints.Vertex;
 import com.tinkerpop.gremlin.java.GremlinPipeline;
@@ -36,12 +43,76 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+
+/**
+ * A class for storing Node and Link information for fast computation
+ * of shortest paths.
+ */
+class Node {
+    class Link {
+	public Node me;			// The node this link originates from
+	public Node neighbor;		// The neighbor node on the other side
+	public short myPort;		// Local port number for the link
+	public short neighborPort;	// Neighbor port number for the link
+
+	/**
+	 * Link constructor.
+	 *
+	 * @param me the node this link originates from.
+	 * @param the neighbor node on the other side of the link.
+	 * @param myPort local port number for the link.
+	 * @param neighborPort neighrobr port number for the link.
+	 */
+	public Link(Node me, Node neighbor, short myPort, short neighborPort) {
+	    this.me = me;
+	    this.neighbor = neighbor;
+	    this.myPort = myPort;
+	    this.neighborPort = neighborPort;
+	}
+    };
+
+    public long nodeId;			// The node ID
+    public LinkedList<Link> links;	// The links originating from this node
+
+    /**
+     * Node constructor.
+     *
+     * @param nodeId the node ID.
+     */
+    public Node(long nodeId) {
+	this.nodeId = nodeId;
+	links = new LinkedList<Link>();
+    }
+
+    /**
+     * Add a neighbor.
+     *
+     * A new link to the neighbor will be created. 
+     *
+     * @param neighbor the neighbor to add.
+     * @param myPort the local port number for the link to the neighbor.
+     * @param neighborPort the neighbor port number for the link.
+     */
+    public void addNeighbor(Node neighbor, short myPort, short neighborPort) {
+	Link link = new Link(this, neighbor, myPort, neighborPort);
+	links.add(link);
+    }
+};
+
 public class TopoRouteService implements IFloodlightModule, ITopoRouteService {
 
     /** The logger. */
     private static Logger log =
 	LoggerFactory.getLogger(TopoRouteService.class);
 
+    //
+    // Topology state for storing (on demand) Switch and Ports info for
+    // fast access during the shortest path computation.
+    // It is explicitly populated by method @ref prepareShortestPathTopo().
+    // See the documentation for that method for details.
+    //
+    HashMap<Long, Node> shortestPathTopo;
+
     @Override
     public Collection<Class<? extends IFloodlightService>> getModuleServices() {
         Collection<Class<? extends IFloodlightService>> l = 
@@ -109,6 +180,239 @@
 	}
     }
 
+    /**
+     * Fetch the Switch and Ports info from the Titan Graph
+     * and store it locally for fast access during the shortest path
+     * computation.
+     *
+     * After fetching the state, method @ref getTopoShortestPath()
+     * can be used for fast shortest path computation.
+     *
+     * Note: There is certain cost to fetch the state, hence it should
+     * be used only when there is a large number of shortest path
+     * computations that need to be done on the same topology.
+     * Typically, a single call to @ref prepareShortestPathTopo()
+     * should be followed by a large number of calls to
+     * method @ref getTopoShortestPath().
+     * After the last @ref getTopoShortestPath() call,
+     * method @ref dropShortestPathTopo() should be used to release
+     * the internal state that is not needed anymore:
+     *
+     *       prepareShortestPathTopo();
+     *       for (int i = 0; i < 10000; i++) {
+     *           dataPath = getTopoShortestPath(...);
+     *           ...
+     *        }
+     *        dropShortestPathTopo();
+     */
+    @Override
+    public void prepareShortestPathTopo() {
+	TitanGraph titanGraph = swStore.graph;
+	TitanTransaction titanTransaction = titanGraph.startTransaction();
+	shortestPathTopo = new HashMap<Long, Node>();
+
+	//
+	// Fetch the relevant info from the Switch and Port vertices
+	// from the Titan Graph.
+	//
+	Iterable<Vertex> nodes = titanTransaction.getVertices("type", "switch");
+	for (Vertex nodeVertex : nodes) {
+	    //
+	    // The Switch info
+	    //
+	    String nodeDpid = nodeVertex.getProperty("dpid").toString();
+	    long nodeId = HexString.toLong(nodeDpid);
+	    Node me = shortestPathTopo.get(nodeId);
+	    if (me == null) {
+		me = new Node(nodeId);
+		shortestPathTopo.put(nodeId, me);
+	    }
+
+	    //
+	    // The local Port info
+	    //
+	    for (Vertex myPortVertex : nodeVertex.getVertices(Direction.OUT, "on")) {
+		short myPort = 0;
+		Object obj = myPortVertex.getProperty("number");
+		if (obj instanceof Short) {
+		    myPort = (Short)obj;
+		} else if (obj instanceof Integer) {
+		    Integer int_nodeId = (Integer)obj;
+		    myPort = int_nodeId.shortValue();
+		}
+
+		//
+		// The neighbor Port info
+		//
+		for (Vertex neighborPortVertex : myPortVertex.getVertices(Direction.OUT, "link")) {
+		    short neighborPort = 0;
+		    obj = neighborPortVertex.getProperty("number");
+		    if (obj instanceof Short) {
+			neighborPort = (Short)obj;
+		    } else if (obj instanceof Integer) {
+			Integer int_nodeId = (Integer)obj;
+			neighborPort = int_nodeId.shortValue();
+		    }
+		    //
+		    // The neighbor Switch info
+		    //
+		    for (Vertex neighborVertex : neighborPortVertex.getVertices(Direction.IN, "on")) {
+			String neighborDpid = neighborVertex.getProperty("dpid").toString();
+			long neighborId = HexString.toLong(neighborDpid);
+			Node neighbor = shortestPathTopo.get(neighborId);
+			if (neighbor == null) {
+			    neighbor = new Node(neighborId);
+			    shortestPathTopo.put(neighborId, neighbor);
+			}
+			me.addNeighbor(neighbor, myPort, neighborPort);
+		    }
+		}
+	    }
+	}
+
+	titanTransaction.stopTransaction(Conclusion.SUCCESS);
+    }
+
+    /**
+     * Release the state that was populated by
+     * method @ref prepareShortestPathTopo().
+     *
+     * See the documentation for method @ref prepareShortestPathTopo()
+     * for additional information and usage.
+     */
+    @Override
+    public void dropShortestPathTopo() {
+	shortestPathTopo = null;
+    }
+
+    /**
+     * Get the shortest path from a source to a destination by
+     * using the pre-populated local topology state prepared
+     * by method @ref prepareShortestPathTopo().
+     *
+     * See the documentation for method @ref prepareShortestPathTopo()
+     * for additional information and usage.
+     *
+     * @param src the source in the shortest path computation.
+     * @param dest the destination in the shortest path computation.
+     * @return the data path with the computed shortest path if
+     * found, otherwise null.
+     */
+    @Override
+    public DataPath getTopoShortestPath(SwitchPort src, SwitchPort dest) {
+	DataPath result_data_path = new DataPath();
+
+	// Initialize the source and destination in the data path to return
+	result_data_path.setSrcPort(src);
+	result_data_path.setDstPort(dest);
+
+	String dpid_src = src.dpid().toString();
+	String dpid_dest = dest.dpid().toString();
+
+	// Get the source vertex
+	Node v_src = shortestPathTopo.get(src.dpid().value());
+	if (v_src == null) {
+	    return null;		// Source vertex not found
+	}
+
+	// Get the destination vertex
+	Node v_dest = shortestPathTopo.get(dest.dpid().value());
+	if (v_dest == null) {
+	    return null;		// Destination vertex not found
+	}
+
+	//
+	// Test whether we are computing a path from/to the same DPID.
+	// If "yes", then just add a single flow entry in the return result.
+	//
+	if (dpid_src.equals(dpid_dest)) {
+	    FlowEntry flowEntry = new FlowEntry();
+	    flowEntry.setDpid(src.dpid());
+	    flowEntry.setInPort(src.port());
+	    flowEntry.setOutPort(dest.port());
+	    result_data_path.flowEntries().add(flowEntry);
+	    return result_data_path;
+	}
+
+	//
+	// Implement the Shortest Path computation by using Breath First Search
+	//
+	Set<Node> visitedSet = new HashSet<Node>();
+	Queue<Node> processingList = new LinkedList<Node>();
+	Map<Node, Node.Link> previousVertexMap = new HashMap<Node, Node.Link>();
+	processingList.add(v_src);
+	visitedSet.add(v_src);
+	Boolean path_found = false;
+	while (! processingList.isEmpty()) {
+	    Node nextVertex = processingList.poll();
+	    if (v_dest == nextVertex) {
+		path_found = true;
+		break;
+	    }
+	    for (Node.Link link : nextVertex.links) {
+		Node child = link.neighbor;
+		if (! visitedSet.contains(child)) {
+		    previousVertexMap.put(child, link);
+		    visitedSet.add(child);
+		    processingList.add(child);
+		}
+	    }
+	}
+	if (! path_found)
+	    return null;		// No path found
+
+	// Collect the path as a list of links
+	List<Node.Link> resultPath = new LinkedList<Node.Link>();
+	Node previousVertex = v_dest;
+	while (! v_src.equals(previousVertex)) {
+	    Node.Link currentLink = previousVertexMap.get(previousVertex);
+	    resultPath.add(currentLink);
+	    previousVertex = currentLink.me;
+	}
+	Collections.reverse(resultPath);
+
+	//
+	// Loop through the result and prepare the return result
+	// as a list of Flow Entries.
+	//
+	Port inPort = new Port(src.port().value());
+	Port outPort;
+	for (Node.Link link: resultPath) {
+	    // Setup the outgoing port, and add the Flow Entry
+	    outPort = new Port(link.neighborPort);
+
+	    FlowEntry flowEntry = new FlowEntry();
+	    flowEntry.setDpid(new Dpid(link.me.nodeId));
+	    flowEntry.setInPort(inPort);
+	    flowEntry.setOutPort(outPort);
+	    result_data_path.flowEntries().add(flowEntry);
+
+	    // Setup the next incoming port
+	    inPort = new Port(link.neighborPort);
+	}
+	if (resultPath.size() > 0) {
+	    // Add the last Flow Entry
+	    FlowEntry flowEntry = new FlowEntry();
+	    flowEntry.setDpid(new Dpid(dest.dpid().value()));
+	    flowEntry.setInPort(inPort);
+	    flowEntry.setOutPort(dest.port());
+	    result_data_path.flowEntries().add(flowEntry);
+	}
+
+	if (result_data_path.flowEntries().size() > 0)
+	    return result_data_path;
+
+	return null;
+    }
+
+    /**
+     * Get the shortest path from a source to a destination.
+     *
+     * @param src the source in the shortest path computation.
+     * @param dest the destination in the shortest path computation.
+     * @return the data path with the computed shortest path if
+     * found, otherwise null.
+     */
     @Override
     public DataPath getShortestPath(SwitchPort src, SwitchPort dest) {
 	DataPath result_data_path = new DataPath();
@@ -118,30 +422,25 @@
 	result_data_path.setDstPort(dest);
 
 	TitanGraph titanGraph = swStore.graph;
+	TitanTransaction titanTransaction = titanGraph.startTransaction();
 
 	String dpid_src = src.dpid().toString();
 	String dpid_dest = dest.dpid().toString();
 
-	//
-	// Implement the Shortest Path between two vertices by using
-	// the following Gremlin CLI code:
-	//   v_src.as("x").out("on").out("link").in("on").dedup().loop("x"){it.object.dpid != v_dest.dpid}.path(){it.dpid}{it.number}{it.number}
-	// The equivalent code used here is:
-	//   results = []; v_src.as("x").out("on").out("link").in("on").dedup().loop("x"){it.object.dpid != v_dest.dpid}.path().fill(results)
-	//
-
 	// Get the source vertex
-	Iterator<Vertex> iter = titanGraph.getVertices("dpid", dpid_src).iterator();
+	Iterator<Vertex> iter = titanTransaction.getVertices("dpid", dpid_src).iterator();
 	if (! iter.hasNext()) {
-	    // titanGraph.stopTransaction(Conclusion.SUCCESS);
+	    titanTransaction.stopTransaction(Conclusion.SUCCESS);
+	    // titanTransaction.shutdown();
 	    return null;		// Source vertex not found
 	}
 	Vertex v_src = iter.next();
 
 	// Get the destination vertex
-	iter = titanGraph.getVertices("dpid", dpid_dest).iterator();
+	iter = titanTransaction.getVertices("dpid", dpid_dest).iterator();
 	if (! iter.hasNext()) {
-	    // titanGraph.stopTransaction(Conclusion.SUCCESS);
+	    titanTransaction.stopTransaction(Conclusion.SUCCESS);
+	    // titanTransaction.shutdown();
 	    return null;		// Destination vertex not found
 	}
 	Vertex v_dest = iter.next();
@@ -149,9 +448,6 @@
 	//
 	// Test whether we are computing a path from/to the same DPID.
 	// If "yes", then just add a single flow entry in the return result.
-	// NOTE: The return value will change in the future to return
-	// a single hop/entry instead of two. Currently, we need
-	// both entries to capture the source and destination ports.
 	//
 	if (dpid_src.equals(dpid_dest)) {
 	    FlowEntry flowEntry = new FlowEntry();
@@ -159,95 +455,135 @@
 	    flowEntry.setInPort(src.port());
 	    flowEntry.setOutPort(dest.port());
 	    result_data_path.flowEntries().add(flowEntry);
-	    // titanGraph.stopTransaction(Conclusion.SUCCESS);
+	    titanTransaction.stopTransaction(Conclusion.SUCCESS);
+	    // titanTransaction.shutdown();
 	    return result_data_path;
 	}
 
-	ShortestPathLoopFunction whileFunction = new ShortestPathLoopFunction(dpid_dest);
-	GremlinPipeline<Vertex, Vertex> pipe = new GremlinPipeline<Vertex, Vertex>();
-	Collection<List> results = new ArrayList<List>();
-	GremlinPipeline<Vertex, List> path;
-	path = pipe.start(v_src).as("x").out("on").out("link").in("on").dedup().loop("x", whileFunction).path();
-	path.fill(results);
+	//
+	// Implement the Shortest Path computation by using Breath First Search
+	//
+	Set<Vertex> visitedSet = new HashSet<Vertex>();
+	Queue<Vertex> processingList = new LinkedList<Vertex>();
+	Map<Vertex, Vertex> previousVertexMap = new HashMap<Vertex, Vertex>();
+
+	processingList.add(v_src);
+	visitedSet.add(v_src);
+	Boolean path_found = false;
+	while (! processingList.isEmpty()) {
+	    Vertex nextVertex = processingList.poll();
+	    if (v_dest.equals(nextVertex)) {
+		path_found = true;
+		break;
+	    }
+	    for (Vertex parentPort : nextVertex.getVertices(Direction.OUT, "on")) {
+		for (Vertex childPort : parentPort.getVertices(Direction.OUT, "link")) {
+		    for (Vertex child : childPort.getVertices(Direction.IN, "on")) {
+			if (! visitedSet.contains(child)) {
+			    previousVertexMap.put(parentPort, nextVertex);
+			    previousVertexMap.put(childPort, parentPort);
+			    previousVertexMap.put(child, childPort);
+			    visitedSet.add(child);
+			    processingList.add(child);
+			}
+		    }
+		}
+	    }
+	}
+	if (! path_found)
+	    return null;		// No path found
+
+	List<Vertex> resultPath = new LinkedList<Vertex>();
+	Vertex previousVertex = v_dest;
+	resultPath.add(v_dest);
+	while (! v_src.equals(previousVertex)) {
+	    Vertex currentVertex = previousVertexMap.get(previousVertex);
+	    resultPath.add(currentVertex);
+	    previousVertex = currentVertex;
+	}
+	Collections.reverse(resultPath);
 
 	//
-	// Loop through the result and collect the list
-	// of <dpid, port> tuples.
+	// Loop through the result and prepare the return result
+	// as a list of Flow Entries.
 	//
 	long nodeId = 0;
 	short portId = 0;
 	Port inPort = new Port(src.port().value());
 	Port outPort = new Port();
-	for (List l : results) {
-	    int idx = 0;
-	    for (Object o: l) {
-		Vertex v = (Vertex)(o);
-		String type = v.getProperty("type").toString();
-		// System.out.println("type: " + type);
-		if (type.equals("port")) {
-		    String number = v.getProperty("number").toString();
-		    // System.out.println("number: " + number);
+	int idx = 0;
+	for (Vertex v: resultPath) {
+	    String type = v.getProperty("type").toString();
+	    // System.out.println("type: " + type);
+	    if (type.equals("port")) {
+		String number = v.getProperty("number").toString();
+		// System.out.println("number: " + number);
 
-		    Object obj = v.getProperty("number");
-		    // String class_str = obj.getClass().toString();
-		    if (obj instanceof Short) {
-			portId = (Short)obj;
-		    } else if (obj instanceof Integer) {
-			Integer int_nodeId = (Integer)obj;
-			portId = int_nodeId.shortValue();
-			// int int_nodeId = (Integer)obj;
-			// portId = (short)int_nodeId.;
-		    }
-		} else if (type.equals("switch")) {
-		    String dpid = v.getProperty("dpid").toString();
-		    nodeId = HexString.toLong(dpid);
+		Object obj = v.getProperty("number");
+		// String class_str = obj.getClass().toString();
+		if (obj instanceof Short) {
+		    portId = (Short)obj;
+		} else if (obj instanceof Integer) {
+		    Integer int_nodeId = (Integer)obj;
+		    portId = int_nodeId.shortValue();
+		    // int int_nodeId = (Integer)obj;
+		    // portId = (short)int_nodeId.;
+		}
+	    } else if (type.equals("switch")) {
+		String dpid = v.getProperty("dpid").toString();
+		nodeId = HexString.toLong(dpid);
 
-		    // System.out.println("dpid: " + dpid);
-		}
-		idx++;
-		if (idx == 1) {
-		    continue;
-		}
-		int mod = idx % 3;
-		if (mod == 0) {
-		    // Setup the incoming port
-		    inPort = new Port(portId);
-		    continue;
-		}
-		if (mod == 2) {
-		    // Setup the outgoing port, and add the Flow Entry
-		    outPort = new Port(portId);
-
-		    FlowEntry flowEntry = new FlowEntry();
-		    flowEntry.setDpid(new Dpid(nodeId));
-		    flowEntry.setInPort(inPort);
-		    flowEntry.setOutPort(outPort);
-		    result_data_path.flowEntries().add(flowEntry);
-		    continue;
-		}
+		// System.out.println("dpid: " + dpid);
 	    }
+	    idx++;
+	    if (idx == 1) {
+		continue;
+	    }
+	    int mod = idx % 3;
+	    if (mod == 0) {
+		// Setup the incoming port
+		inPort = new Port(portId);
+		continue;
+	    }
+	    if (mod == 2) {
+		// Setup the outgoing port, and add the Flow Entry
+		outPort = new Port(portId);
 
-	    if (idx > 0) {
-		// Add the last Flow Entry
 		FlowEntry flowEntry = new FlowEntry();
 		flowEntry.setDpid(new Dpid(nodeId));
 		flowEntry.setInPort(inPort);
-		flowEntry.setOutPort(dest.port());
+		flowEntry.setOutPort(outPort);
 		result_data_path.flowEntries().add(flowEntry);
+		continue;
 	    }
 	}
-	// titanGraph.stopTransaction(Conclusion.SUCCESS);
+	if (idx > 0) {
+	    // Add the last Flow Entry
+	    FlowEntry flowEntry = new FlowEntry();
+	    flowEntry.setDpid(new Dpid(nodeId));
+	    flowEntry.setInPort(inPort);
+	    flowEntry.setOutPort(dest.port());
+	    result_data_path.flowEntries().add(flowEntry);
+	}
+
+	titanTransaction.stopTransaction(Conclusion.SUCCESS);
+	// titanTransaction.shutdown();
 	if (result_data_path.flowEntries().size() > 0)
 	    return result_data_path;
 
 	return null;
     }
 
+    /**
+     * Test whether a route exists from a source to a destination.
+     *
+     * @param src the source node for the test.
+     * @param dest the destination node for the test.
+     * @return true if a route exists, otherwise false.
+     */
     @Override
     public Boolean routeExists(SwitchPort src, SwitchPort dest) {
 	DataPath dataPath = getShortestPath(src, dest);
-	if (dataPath != null)
-	    return true;
-	return false;
+	return (dataPath != null);
     }
 }