Mobile to Web stream does not attach in WebRTC Call - webrtc

Question

When I do call between two browsers, I get the following offer from other browser:
{"sdp":"v=0\r\n
o=- 7536355095180056736 2 IN IP4 127.0.0.1\r\n
s=-\r\n
t=0 0\r\n
a=group:BUNDLE audio video\r\n
a=msid-semantic: WMS kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD\r\n
m=audio 9 RTP/SAVPF 111 103 104 9 0 8 106 105 13 126\r\n
c=IN IP4 0.0.0.0\r\n
a=rtcp:9 IN IP4 0.0.0.0\r\n
a=ice-ufrag:xA0sdUZO/vAhvhQG\r\n
a=ice-pwd:Re8aNMs38GOfZ581+F6CKl8t\r\n
a=ice-options:google-ice\r\n
a=fingerprint:sha-256 2C:E2:54:76:12:24:36:4D:10:66:24:24:0D:18:63:DB:51:7E:AD:B5:BE:96:C5:43:C7:6D:3C:95:4D:4F:7B:FD\r\n
a=setup:actpass\r\n
a=mid:audio\r\n
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\n
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\n
a=sendrecv\r\n
a=rtcp-mux\r\n
a=rtpmap:111 opus/48000/2\r\n
a=fmtp:111 minptime=10\r\n
a=rtpmap:103 ISAC/16000\r\n
a=rtpmap:104 ISAC/32000\r\n
a=rtpmap:9 G722/8000\r\n
a=rtpmap:0 PCMU/8000\r\n
a=rtpmap:8 PCMA/8000\r\n
a=rtpmap:106 CN/32000\r\n
a=rtpmap:105 CN/16000\r\n
a=rtpmap:13 CN/8000\r\n
a=rtpmap:126 telephone-event/8000\r\n
a=maxptime:60\r\n
a=ssrc:1065921633 cname:Gvk84VJyPRAri/jA\r\n
a=ssrc:1065921633 msid:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD c0116fd8-aef9-4eba-8297-98b9069973c0\r\n
a=ssrc:1065921633 mslabel:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD\r\n
a=ssrc:1065921633 label:c0116fd8-aef9-4eba-8297-98b9069973c0\r\n
m=video 9 RTP/SAVPF 100 116 117 96\r\n
c=IN IP4 0.0.0.0\r\n
a=rtcp:9 IN IP4 0.0.0.0\r\n
a=ice-ufrag:xA0sdUZO/vAhvhQG\r\n
a=ice-pwd:Re8aNMs38GOfZ581+F6CKl8t\r\n
a=ice-options:google-ice\r\na=fingerprint:sha-256 2C:E2:54:76:12:24:36:4D:10:66:24:24:0D:18:63:DB:51:7E:AD:B5:BE:96:C5:43:C7:6D:3C:95:4D:4F:7B:FD\r\n
a=setup:actpass\r\n
a=mid:video\r\n
a=extmap:2 urn:ietf:params:rtp-hdrext:toffset\r\n
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\n
a=sendrecv\r\n
a=rtcp-mux\r\n
a=rtpmap:100 VP8/90000\r\n
a=rtcp-fb:100 ccm fir\r\n
a=rtcp-fb:100 nack\r\n
a=rtcp-fb:100 nack pli\r\n
a=rtcp-fb:100 goog-remb\r\n
a=rtpmap:116 red/90000\r\n
a=rtpmap:117 ulpfec/90000\r\n
a=rtpmap:96 rtx/90000\r\n
a=fmtp:96 apt=100\r\n
a=ssrc-group:FID 1938891203 2482888767\r\n
a=ssrc:1938891203 cname:Gvk84VJyPRAri/jA\r\n
a=ssrc:1938891203 msid:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD 4bd70627-5383-4da1-9dd9-1c6d8a8f21b2\r\n
a=ssrc:1938891203 mslabel:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD\r\n
a=ssrc:1938891203 label:4bd70627-5383-4da1-9dd9-1c6d8a8f21b2\r\n
a=ssrc:2482888767 cname:Gvk84VJyPRAri/jA\r\n
a=ssrc:2482888767 msid:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD 4bd70627-5383-4da1-9dd9-1c6d8a8f21b2\r\n
a=ssrc:2482888767 mslabel:kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD\r\n
a=ssrc:2482888767 label:4bd70627-5383-4da1-9dd9-1c6d8a8f21b2\r\n
","type":"offer",
"from":"-tMt8kJad6P8AfSnLjyh"}
And following is the stream object which I get inside 'event' when onaddstream() of PeerConnection object is called:
{"onremovetrack":null,
"onaddtrack":null,
"onended":null,
"ended":false,
"id":"kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD",
"label":"kZEpfQv0bZYsCa56HHy2eMo3E4A71KXCApdD"}
It works fine. Video stream gets attached to the source element. However, When I try to call from mobile to browser... (mobile becomes the one to send the offer) I get following offer object on browser from mobile:
{"type":"offer",
"sdp":"v=0\r\n
o=- 8571015662826724969 2 IN IP4 127.0.0.1\r\n
s=-\r\n
t=0 0\r\n
a=group:BUNDLE audio video\r\n
a=msid-semantic: WMS ARDAMS\r\n
m=audio 9 RTP/SAVPF 103 111 9 102 0 8 106 105 13 127 126 \r\n
c=IN IP4 0.0.0.0\r\n
a=rtcp:9 IN IP4 0.0.0.0\r\n
a=ice-ufrag:JKMUpFQiL+ZHZr/V\r\n
a=ice-pwd:rLL5A3k9pBwxCsM2IzNAu2xM\r\n
a=ice-options:google-ice\r\n
a=fingerprint:sha-1 B0:E7:56:DF:C6:D9:E4:08:10:DB:A1:7B:9B:C6:65:2C:29:64:38:E1\r\n
a=setup:actpass\r\n
a=mid:audio\r\n
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\n
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\n
a=sendrecv\r\n
a=rtcp-mux\r\n
a=rtpmap:111 opus/48000/2\r\n
a=fmtp:111 minptime=10; useinbandfec=1\r\n
a=rtpmap:103 ISAC/16000\r\n
a=rtpmap:9 G722/8000\r\n
a=rtpmap:102 ILBC/8000\r\n
a=rtpmap:0 PCMU/8000\r\n
a=rtpmap:8 PCMA/8000\r\n
a=rtpmap:106 CN/32000\r\n
a=rtpmap:105 CN/16000\r\n
a=rtpmap:13 CN/8000\r\n
a=rtpmap:127 red/8000\r\n
a=rtpmap:126 telephone-event/8000\r\n
a=maxptime:60\r\n
a=ssrc:2978495626 cname:MJvVwIPq7NgXaDF6\r\n
a=ssrc:2978495626 msid:ARDAMS ARDAMSa0\r\n
a=ssrc:2978495626 mslabel:ARDAMS\r\n
a=ssrc:2978495626 label:ARDAMSa0\r\n
m=video 9 RTP/SAVPF 100 116 117 96\r\n
c=IN IP4 0.0.0.0\r\n
a=rtcp:9 IN IP4 0.0.0.0\r\n
a=ice-ufrag:JKMUpFQiL+ZHZr/V\r\n
a=ice-pwd:rLL5A3k9pBwxCsM2IzNAu2xM\r\n
a=ice-options:google-ice\r\n
a=fingerprint:sha-1 B0:E7:56:DF:C6:D9:E4:08:10:DB:A1:7B:9B:C6:65:2C:29:64:38:E1\r\n
a=setup:actpass\r\n
a=mid:video\r\n
a=extmap:2 urn:ietf:params:rtp-hdrext:toffset\r\n
a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\n
a=sendrecv\r\n
a=rtcp-mux\r\n
a=rtpmap:100 VP8/90000\r\n
a=rtcp-fb:100 ccm fir\r\n
a=rtcp-fb:100 nack\r\n
a=rtcp-fb:100 nack pli\r\n
a=rtcp-fb:100 goog-remb\r\n
a=rtpmap:116 red/90000\r\n
a=rtpmap:117 ulpfec/90000\r\n
a=rtpmap:96 rtx/90000\r\n
a=fmtp:96 apt=100\r\n
a=ssrc-group:FID 899049567 490613521\r\n
a=ssrc:899049567 cname:MJvVwIPq7NgXaDF6\r\n
a=ssrc:899049567 msid:ARDAMS ARDAMSv0\r\n
a=ssrc:899049567 mslabel:ARDAMS\r\n
a=ssrc:899049567 label:ARDAMSv0\r\n
a=ssrc:490613521 cname:MJvVwIPq7NgXaDF6\r\n
a=ssrc:490613521 msid:ARDAMS ARDAMSv0\r\n
a=ssrc:490613521 mslabel:ARDAMS\r\n
a=ssrc:490613521 label:ARDAMSv0\r\n"}
And following is the stream object which I get inside 'event' when onaddstream() of PeerConnection object is called:
{"onremovetrack":null,
"onaddtrack":null,
"onended":null,
"ended":false,
"id":"ARDAMS",
"label":"ARDAMS"}
When I attach this to video element of HTML page. It shows nothing but 'half black half white' square.
Both peers are able to send ICE candidates too. They are able to send offer and answer to each other. They attach their local stream to the peer connection object.
What could possibly be wrong with this? Can anyone guide me in this?
Thanks.