diff --git a/app.js b/app.js
index e25930044..71b797fc9 100644
--- a/app.js
+++ b/app.js
@@ -265,6 +265,72 @@ function sendKeyframe(pc) {
     );
 }
 
+function demonstrateabug(pc) {
+    // funny way of doing mute. the subsequent offer contains things like rtcp-mux
+    // and triggers all new ice candidates (ice restart)
+    // this code is here to demonstrate a bug
+    pc.createOffer(
+        function (offer) {
+            console.log(offer);
+            var sdp = new SDP(offer.sdp);
+            if (sdp.media.length > 1) {
+                sdp.media[1] = sdp.media[1].replace('a=sendrecv', 'a=recvonly');
+                sdp.raw = sdp.session + sdp.media.join('');
+                offer.sdp = sdp.raw;
+                pc.setLocalDescription(offer,
+                    function () {
+                        console.log('mute SLD ok');
+                    },
+                    function(error) {
+                        console.log('mute SLD error');
+                    }
+                );
+            }
+        },
+        function (error) {
+            console.warn(error);
+        },
+        {mandatory: {OfferToReceiveAudio: true, OfferToReceiveVideo: false}}
+    );
+}
+
+// really mute video, i.e. dont even send black frames
+function muteVideo(pc, unmute) {
+    // FIXME: this probably needs another of those lovely state safeguards...
+    // which checks for iceconn == connected and sigstate == stable
+    pc.setRemoteDescription(pc.remoteDescription,
+        function () {
+            pc.createAnswer(
+                function (answer) {
+                    var sdp = new SDP(answer.sdp);
+                    if (sdp.media.length > 1) {
+                        if (unmute)
+                            sdp.media[1] = sdp.media[1].replace('a=recvonly', 'a=sendrecv');
+                        else
+                            sdp.media[1] = sdp.media[1].replace('a=sendrecv', 'a=recvonly');
+                        sdp.raw = sdp.session + sdp.media.join('');
+                        answer.sdp = sdp.raw;
+                    }
+                    pc.setLocalDescription(answer,
+                        function () {
+                            console.log('mute SLD ok');
+                        },
+                        function(error) {
+                            console.log('mute SLD error');
+                        }
+                    );
+                },
+                function (error) {
+                    console.log(error);
+                }
+            );
+        },
+        function (error) {
+            console.log('muteVideo SRD error');
+        }
+    );
+}
+
 $(document).bind('callincoming.jingle', function (event, sid) {
     var sess = connection.jingle.sessions[sid];
     // TODO: check affiliation and/or role
@@ -1215,4 +1281,4 @@ function createEditDisplayNameButton() {
     editButton.innerHTML = '<i class="fa fa-pencil"></i>';
 
     return editButton;
-}
\ No newline at end of file
+}