diff --git a/web/ons-demo/RELEASE_NOTES.txt b/web/ons-demo/RELEASE_NOTES.txt
index 916a965..90af6d1 100644
--- a/web/ons-demo/RELEASE_NOTES.txt
+++ b/web/ons-demo/RELEASE_NOTES.txt
@@ -1,11 +1,20 @@
 ** April 4, 2013 **
+iperf display implemented
+- scaled to 50,000,000
+- update rate is every 2s
+- the display does not draw until receiving 2 buffers of data (this way if there is a stale buffer it doesn't get displayed)
+- duration is 10000 seconds. seems like there is no need for a button to restart?
+- displaying 10s data
+- if the data underruns (either because the server response is too slow or because the iperf data stops being updated) the display draws 0s
+- seeing the data stall a lot (timestamp and end-time remain the same through many fetches)
+
+** April 4, 2013 **
 Fix issues:
 	305 - "close x" now unselects flow. double click to delete a flow
 	323 - gui now recovers on timeout errors and polls again
 	324 - fixed problem with added flows not displaying
 	325 - fixed logic displaying flows in topology view
 
-
 ** March 28, 2013 **
 - add and delete flow implemented
 - to add flow
diff --git a/web/ons-demo/css/layout.default.css b/web/ons-demo/css/layout.default.css
index 018e728..5e1f1ce 100644
--- a/web/ons-demo/css/layout.default.css
+++ b/web/ons-demo/css/layout.default.css
@@ -76,6 +76,15 @@
 .iperf {
 	width: 100%;
 	-webkit-box-flex: 1.0;
+	position: relative;
+	display: -webkit-box;
+}
+
+.iperf-container {
+	position: absolute;
+	top: 0px;
+	height: 100%;
+	width: 100%;
 }
 
 #controllers {
diff --git a/web/ons-demo/css/skin.default.css b/web/ons-demo/css/skin.default.css
index 1ce4897..1d656b0 100644
--- a/web/ons-demo/css/skin.default.css
+++ b/web/ons-demo/css/skin.default.css
@@ -145,6 +145,12 @@
 	border-top: 1px solid #AAA;
 }
 
+path.iperfdata {
+	fill: none;
+	stroke-width: 2px;
+	stroke: rgba(255, 255, 255, .75);
+}
+
 #flowChooser {
 	pointer-events: none;
 	background-color: rgba(0, 0, 0, .25);
diff --git a/web/ons-demo/js/app.js b/web/ons-demo/js/app.js
index 695e4bb..d6fa983 100644
--- a/web/ons-demo/js/app.js
+++ b/web/ons-demo/js/app.js
@@ -96,7 +96,7 @@
 				return;
 			}
 			var pts = [];
-			if (!d.dataPath.flowEntries || !d.dataPath.flowEntries.length) {
+			if (!d.dataPath.flowEntries) {
 				// create a temporary vector to indicate the pending flow
 				var s1 = d3.select(document.getElementById(d.dataPath.srcPort.dpid.value));
 				var s2 = d3.select(document.getElementById(d.dataPath.dstPort.dpid.value));
@@ -128,7 +128,11 @@
 					}
 				});
 			}
-			return line(pts);
+			if (pts.length) {
+				return line(pts);
+			} else {
+				return "M0,0";
+			}
 		})
 		.attr('id', function (d) {
 			if (d) {
@@ -153,6 +157,16 @@
 		row.append('div').classed('dstDPID', true);
 		row.append('div').classed('iperf', true);
 
+		row.select('.iperf')
+			.append('div')
+			.attr('class', 'iperf-container')
+			.append('svg:svg')
+			.attr('viewBox', '0 0 1000 32')
+			.attr('preserveAspectRatio', 'none')
+			.append('svg:g')
+			.append('svg:path')
+			.attr('class', 'iperfdata');
+
 		row.on('mouseover', function (d) {
 			if (d) {
 				var path = document.getElementById(makeFlowKey(d));
@@ -164,14 +178,24 @@
 				var path = document.getElementById(makeFlowKey(d));
 				d3.select(path).classed('highlight', false);
 			}
-		})
+		});
 	}
 
 	function rowUpdate(d) {
 		var row = d3.select(this);
+		row.attr('id', function (d) {
+			if (d) {
+				return makeSelectedFlowKey(d);
+			}
+		});
+
+		if (!d || !hasIPerf(d)) {
+			row.select('.iperfdata')
+				.attr('d', 'M0,0');
+		}
+
 		row.select('.deleteFlow').on('click', function () {
-			selectedFlows[selectedFlows.indexOf(d)] = null;
-			updateSelectedFlows();
+			deselectFlow(d);
 		});
 		row.on('dblclick', function () {
 			if (d) {
@@ -232,6 +256,73 @@
 	flows.exit().remove();
 }
 
+// TODO: cancel the interval when the flow is desel
+function startIPerfForFlow(flow) {
+	var duration = 10000; // seconds
+	var interval = 100; // ms. this is defined by the server
+	var updateRate = 2000; // ms
+
+	function makePoints() {
+		var pts = [];
+		var i;
+		for (i=0; i < 100; ++i) {
+			var sample = flow.iperfData.samples[i];
+			var height = 32 * sample/50000000;
+			if (height > 32)
+				height = 32;
+			pts.push({
+				x: i * 1000/99,
+				y: 32 - height
+			})
+		}
+		return pts;
+	}
+
+	if (flow.flowId) {
+		console.log('starting iperf for: ' + flow.flowId.value);
+		startIPerf(flow, duration, updateRate/interval);
+		flow.iperfDisplayInterval = setInterval(function () {
+			if (flow.iperfData) {
+				while (flow.iperfData.samples.length < 100) {
+					flow.iperfData.samples.push(0);
+				}
+				var iperfPath = d3.select(document.getElementById(makeSelectedFlowKey(flow))).select('path');
+				iperfPath.attr('d', line(makePoints()));
+				flow.iperfData.samples.shift();
+			}
+
+
+		}, interval);
+		flow.iperfFetchInterval = setInterval(function () {
+			getIPerfData(flow, function (data) {
+				try {
+					if (!flow.iperfData) {
+						flow.iperfData = {
+							samples: []
+						};
+						var i;
+						for (i = 0; i < 100; ++i) {
+							flow.iperfData.samples.push(0);
+						}
+					}
+
+					var iperfData = JSON.parse(data);
+					// if the data is fresh
+					if (flow.iperfData.timestamp && iperfData.timestamp != flow.iperfData.timestamp) {
+						iperfData.samples.forEach(function (s) {
+							flow.iperfData.samples.push(s);
+						});
+					}
+					flow.iperfData.timestamp = iperfData.timestamp;
+				} catch (e) {
+					console.log('bad iperf data: ' + data);
+				}
+//				console.log(data);
+			});
+		}, updateRate/2); // over sample to avoid gaps
+	}
+}
+
 function updateSelectedFlows() {
 	// make sure that all of the selected flows are either
 	// 1) valid (meaning they are in the latest list of flows)
@@ -249,13 +340,22 @@
 				if (liveFlow) {
 					newSelectedFlows.push(liveFlow);
 					liveFlow.deletePending = flow.deletePending;
+					liveFlow.iperfFetchInterval = flow.iperfFetchInterval;
+					liveFlow.iperfDisplayInterval = flow.iperfDisplayInterval;
 				} else if (flow.createPending) {
 					newSelectedFlows.push(flow);
+				} else if (hasIPerf(flow)) {
+					clearIPerf(flow);
 				}
 			}
 		});
 		selectedFlows = newSelectedFlows;
 	}
+	selectedFlows.forEach(function (flow) {
+		if (!hasIPerf(flow)) {
+			startIPerfForFlow(flow);
+		}
+	});
 	while (selectedFlows.length < 3) {
 		selectedFlows.push(null);
 	}
@@ -280,6 +380,19 @@
 	}
 }
 
+function hasIPerf(flow) {
+	return flow && flow.iperfFetchInterval;
+}
+
+function clearIPerf(flow) {
+	console.log('clearing iperf interval for: ' + flow.flowId.value);
+	clearInterval(flow.iperfFetchInterval);
+	delete flow.iperfFetchInterval;
+	clearInterval(flow.iperfDisplayInterval);
+	delete flow.iperfDisplayInterval;
+	delete flow.iperfData;
+}
+
 function deselectFlow(flow, ifCreatePending) {
 	var flowKey = makeFlowKey(flow);
 	var newSelectedFlows = [];
@@ -288,6 +401,10 @@
 				flowKey !== makeFlowKey(flow) ||
 				flowKey === makeFlowKey(flow) && ifCreatePending && !flow.createPending ) {
 			newSelectedFlows.push(flow);
+		} else {
+			if (hasIPerf(flow)) {
+				clearIPerf(flow);
+			}
 		}
 	});
 	selectedFlows = newSelectedFlows;
@@ -474,6 +591,10 @@
 	return flow.dataPath.srcPort.dpid.value + '=>' + flow.dataPath.dstPort.dpid.value;
 }
 
+function makeSelectedFlowKey(flow) {
+	return 'S' + makeFlowKey(flow);
+}
+
 function createLinkMap(links) {
 	var linkMap = {};
 	links.forEach(function (link) {
@@ -1066,6 +1187,7 @@
 
 }
 
+var modelString;
 function sync(svg) {
 	var d = Date.now();
 	updateModel(function (newModel) {
@@ -1073,9 +1195,11 @@
 
 		if (newModel) {
 			var modelChanged = false;
-			if (!model || JSON.stringify(model) != JSON.stringify(newModel)) {
+			var newModelString = JSON.stringify(newModel);
+			if (!modelString || newModelString != modelString) {
 				modelChanged = true;
 				model = newModel;
+				modelString = newModelString;
 			} else {
 	//			console.log('no change');
 			}
diff --git a/web/ons-demo/js/controller.js b/web/ons-demo/js/controller.js
index fd3f6ae..c7c80ec 100644
--- a/web/ons-demo/js/controller.js
+++ b/web/ons-demo/js/controller.js
@@ -1,11 +1,14 @@
 /*global d3*/
 
-function callURL(url) {
+function callURL(url, cb) {
 	d3.text(url, function (error, result) {
 		if (error) {
 			alert(url + ' : ' + error.status);
 		} else {
-			console.log(result);
+			if (cb) {
+				cb(result);
+			}
+//			console.log(result);
 		}
 	});
 }
@@ -37,6 +40,16 @@
 	delFlowCmd: function (flow) {
 		var url = '/proxy/gui/delflow/' + flow.flowId.value;
 		callURL(url);
+	},
+	startIPerfCmd: function (flow, duration, numSamples) {
+		var flowId = parseInt(flow.flowId.value, 16);
+		var url = '/proxy/gui/iperf/start/' + [flowId, duration, numSamples].join('/');
+		callURL(url)
+	},
+	getIPerfDataCmd: function (flow, cb) {
+		var flowId = parseInt(flow.flowId.value, 16);
+		var url = '/proxy/gui/iperf/rate/' + flowId;
+		callURL(url, cb);
 	}
 };
 
@@ -70,4 +83,12 @@
 
 function deleteFlow(flow) {
 	controllerFunctions.delFlowCmd(flow);
+}
+
+function startIPerf(flow, duration, numSamples) {
+	controllerFunctions.startIPerfCmd(flow, duration, numSamples);
+}
+
+function getIPerfData(flow, cb) {
+	controllerFunctions.getIPerfDataCmd(flow, cb);
 }
\ No newline at end of file
diff --git a/web/topology_rest.py b/web/topology_rest.py
index f17d6ba..84e12da 100755
--- a/web/topology_rest.py
+++ b/web/topology_rest.py
@@ -153,6 +153,34 @@
 
   resp = Response(result, status=200, mimetype='application/json')
   return resp
+
+@app.route("/proxy/gui/iperf/start/<flow_id>/<duration>/<samples>")
+def proxy_iperf_start(flow_id,duration,samples):
+  try:
+    command = "curl -s %s/gui/iperf/start/%s/%s/%s" % (ONOS_GUI3_CONTROL_HOST, flow_id, duration, samples)
+    print command
+    result = os.popen(command).read()
+  except:
+    print "REST IF has issue"
+    exit
+
+  resp = Response(result, status=200, mimetype='application/json')
+  return resp
+
+@app.route("/proxy/gui/iperf/rate/<flow_id>")
+def proxy_iperf_rate(flow_id):
+  try:
+    command = "curl -s %s/gui/iperf/rate/%s" % (ONOS_GUI3_CONTROL_HOST, flow_id)
+    print command
+    result = os.popen(command).read()
+  except:
+    print "REST IF has issue"
+    exit
+
+  resp = Response(result, status=200, mimetype='application/json')
+  return resp
+
+
 @app.route("/wm/core/topology/switches/all/json")
 def switches():
   if request.args.get('proxy') == None:
@@ -204,7 +232,7 @@
     print "REST IF has issue"
     exit
 
-    
+
   resp = Response(result, status=200, mimetype='application/json')
   return resp