bwtest - congestion control and stats using channel.bufferedAmount

node-webrtc · Apr 3, 2015 · bb21ac5 · bb21ac5
1 parent 6bbb583
commit bb21ac5
Showing 1 changed file with 57 additions and 11 deletions.
diff --git a/test/bwtest.js b/test/bwtest.js
@@ -20,23 +20,35 @@ var SimplePeer = require('simple-peer');
 
 function bwtest(peer1, peer2) {
     var START_TIME = Date.now();
-    var BUFFERED_DELAY_MS = 10;
-    var NPACKETS = 10000;
+    var BUFFERED_DELAY_MS = 5;
+    var NPACKETS = 5000;
     var PACKET_SIZE = 16 * 1024;
+    var CONGEST_HIGH_THRESHOLD = 1 * 1024 * 1024;
+    var CONGEST_LOW_THRESHOLD = 256 * 1024;
     var buffer = new ArrayBuffer(PACKET_SIZE);
     var n = 0;
+    var congested = 0;
     var stats = {
         count: 0,
         bytes: 0,
+        congestCount: 0,
+        congestTime: 0
     };
 
     function info() {
-        var took = (Date.now() - START_TIME) / 1000;
-        var buffered = peer1._channel && peer1._channel.bufferedAmount;
-        return 'sent ' + n + ' received ' + stats.count +
-            (buffered ? ' buffered ' + buffered : '') +
-            ' took ' + took.toFixed(3) + ' seconds' +
-            ' bandwidth ' + (stats.bytes / took / 1024).toFixed(0) + ' KB/s';
+        var now = Date.now();
+        if (congested) {
+            stats.congestTime += Date.now() - congested;
+            congested = now;
+        }
+        var took = (now - START_TIME) / 1000;
+        var bufferedAmount = peer1._channel && peer1._channel.bufferedAmount;
+        return 'sent ' + n + ' received ' + stats.count + '. ' +
+            'congestion #' + stats.congestCount + ' ' +
+            (stats.congestTime / 1024).toFixed(3) + ' seconds. ' +
+            (bufferedAmount ? 'bufferedAmount ' + bufferedAmount + '. ' : '') +
+            'took ' + took.toFixed(3) + ' seconds. ' +
+            'bandwidth ' + (stats.bytes / took / 1024).toFixed(0) + ' KB/s. ';
     }
 
     peer2.on('data', function(data) {
@@ -49,6 +61,23 @@ function bwtest(peer1, peer2) {
         }
     });
 
+    function congestion() {
+        var bufferedAmount = peer1._channel && peer1._channel.bufferedAmount || 0;
+        if ((bufferedAmount > CONGEST_HIGH_THRESHOLD) ||
+            (congested && bufferedAmount > CONGEST_LOW_THRESHOLD)) {
+            if (!congested) {
+                congested = Date.now();
+            }
+            stats.congestCount += 1;
+        } else {
+            if (congested) {
+                stats.congestTime += Date.now() - congested;
+            }
+            congested = 0;
+        }
+        return congested;
+    }
+
     function send() {
         if (n >= NPACKETS) {
             console.log('SEND DONE!', info());
@@ -57,8 +86,7 @@ function bwtest(peer1, peer2) {
         if (n % 100 === 0) {
             console.log('SENDING:', info());
         }
-        if (peer1._channel && peer1._channel.bufferedAmount) {
-            console.log('WAITING:', info());
+        if (congestion()) {
             setTimeout(send, BUFFERED_DELAY_MS);
             return;
         }
@@ -81,7 +109,25 @@ function bwtest(peer1, peer2) {
 
 function init(callback) {
     var INITIATOR_CONFIG = {
-        initiator: true
+        initiator: true,
+        config: {
+            iceServers: [{
+                url: 'stun:23.21.150.121'
+            }],
+
+            /*
+             * data channels are ordered by default - using unordered channel improves
+             * performance but will likely require ordering in another app layer
+             */
+            ordered: false,
+
+            /*
+             * data channels are reliable by default - using either maxRetransmits
+             * or maxPacketLifeTime will change to unreliable mode
+             */
+            // maxRetransmits: 5,
+            // maxPacketLifeTime: 3000,
+        }
     };
     var peer1 = new SimplePeer(INITIATOR_CONFIG);
     var peer2 = new SimplePeer();