title: WebRTC: setRemoteDescription throwing error
body: <p>I have been using one of the open-source(Muaz Khan's) library for WebRTC. The following error is thrown in the following line of code : </p>
  
  <pre><code>peer.setRemoteDescription(new RTCSessionDescription(remoteSdp), cb || function() {}, function(error) {
     if (!!connection.enableLogs) {
       console.error(JSON.stringify(error, null, '\t'), '\n', remoteSdp.type, remoteSdp.sdp);
     }
   });
  </code></pre>
  
  <p>Following is the error message:</p>
  
  <pre><code>{}
      answer v=0
      o=- 1466540501886325415 2 IN IP4 127.0.0.1
      s=-
      t=0 0
      a=group:BUNDLE audio video
      a=msid-semantic: WMS
      m=audio 9 UDP/TLS/RTP/SAVPF 111 103 104 9 0 8 126
      c=IN IP4 0.0.0.0
      a=rtcp:9 IN IP4 0.0.0.0
      a=ice-ufrag:+Tp2MN9xkz9Zfn8C
      a=ice-pwd:aniPn401PK7bAWCIHV63TPhl
      a=fingerprint:sha-256 EC:BB:E4:B5:C2:6B:17:29:E4:CF:BD:8E:8A:5E:D1:BB:59:CA:8F:7D:E3:6B:CF:1D:89:DB:0B:17:AC:65:75:F4
      a=setup:active
      a=mid:audio
      b=AS:128
      a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
      a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
      a=recvonly
      a=rtcp-mux
      a=rtpmap:111 opus/48000/2
      a=rtcp-fb:111 transport-cc
      a=fmtp:111 minptime=10; useinbandfec=1; stereo=1; sprop-stereo=1; maxaveragebitrate=1048576; maxplaybackrate=1048576; stereo=1; sprop-stereo=1; maxaveragebitrate=1048576; maxplaybackrate=1048576
      a=maxptime:3
      a=maxptime:3
      a=rtpmap:103 ISAC/16000
      a=rtpmap:104 ISAC/32000
      a=rtpmap:9 G722/8000
      a=rtpmap:0 PCMU/8000
      a=rtpmap:8 PCMA/8000
      a=rtpmap:126 telephone-event/8000
      a=maxptime:60
      m=video 9 UDP/TLS/RTP/SAVPF 101 100 116 117 96 97 98
      c=IN IP4 0.0.0.0
      a=rtcp:9 IN IP4 0.0.0.0
      a=ice-ufrag:+Tp2MN9xkz9Zfn8C
      a=ice-pwd:aniPn401PK7bAWCIHV63TPhl
      a=fingerprint:sha-256 EC:BB:E4:B5:C2:6B:17:29:E4:CF:BD:8E:8A:5E:D1:BB:59:CA:8F:7D:E3:6B:CF:1D:89:DB:0B:17:AC:65:75:F4
      a=setup:active
      a=mid:video
      b=AS:512
      a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
      a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
      a=extmap:4 urn:3gpp:video-orientation
      a=recvonly
      a=rtcp-mux
      a=rtpmap:101 VP9/90000
      a=rtcp-fb:101 ccm fir
      a=rtcp-fb:101 nack
      a=rtcp-fb:101 nack pli
      a=rtcp-fb:101 goog-remb
      a=rtcp-fb:101 transport-cc
      a=rtpmap:100 VP8/90000
      a=rtcp-fb:100 ccm fir
      a=rtcp-fb:100 nack
      a=rtcp-fb:100 nack pli
      a=rtcp-fb:100 goog-remb
      a=rtcp-fb:100 transport-cc
      a=rtpmap:116 red/90000
      a=rtpmap:117 ulpfec/90000
      a=rtpmap:96 rtx/90000
      a=fmtp:96 apt=100
      a=fmtp:100 x-google-min-bitrate=4194304; x-google-max-bitrate=4194304
      a=fmtp:100 x-google-min-bitrate=4194304; x-google-max-bitrate=4194304
      a=rtpmap:97 rtx/90000
      a=fmtp:97 apt=101
      a=rtpmap:98 rtx/90000
      a=fmtp:98 apt=116
  </code></pre>
  
  <p>First of all, is the SDP valid and if it is what could possibly cause the error?</p>