Hi, I've made a simple Android Java application utilizing JAIN SIP, webrtc.org android library and connected to FreeSwitch via UDP. But when I send SDP from SIP/Chrome/Firefox phone to my JAIN SIP client this SDP is not managed well by FreeSwitch for establishment WebRTC PeerConnection. When I call `peerConnection.setRemoteDescription(new SDPObserver(), sdp);` in my Android Application with the SDP from FreeSwitch I get: "onSetFailure Failed to set remote offer sdp: Called with SDP without DTLS fingerprint." At the same time the calls between Chrome/Firefox(http://tryit.jssip.net/) and SIP-phone (e.g. linphone) greatly managed by FreeSwitch and I have pure audio flow. Here is initial SDP from Chrome (http://tryit.jssip.net/): v=0 o=- 6887715720880489867 2 IN IP4 127.0.0.1 s=- t=0 0 a=group:BUNDLE audio video a=msid-semantic: WMS itEKr0vXP6lg3KNs4kVau9aL3uAfyWOlItfU m=audio 38359 RTP/SAVPF 111 103 104 0 8 106 105 13 126 c=IN IP4 192.168.122.1 a=rtcp:38359 IN IP4 192.168.122.1 a=candidate:4062413514 1 udp 2122260223 192.168.122.1 38359 typ host generation 0 ....... a=candidate:3741779331 2 tcp 1518018303 172.17.42.1 0 typ host tcptype active generation 0 a=ice-ufrag:bwrCv9yS8rCY12Az a=ice-pwd:3k35jpG/i+TCbvBcJPWrw2eP a=ice-options:google-ice a=*fingerprint*:sha-256 52:8C:0F:27:C6:D6:CF:AE:F4:87:AC:AE:DF:7B:9B:B2:75:90:60:6A:2A:82:09:98:AD:04:0B:35:45:6A:13:A2 a=setup:actpass a=mid:audio 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=sendrecv a=rtcp-mux a=rtpmap:111 opus/48000/2 a=fmtp:111 minptime=10 a=rtpmap:103 ISAC/16000 a=rtpmap:104 ISAC/32000 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:106 CN/32000 a=rtpmap:105 CN/16000 a=rtpmap:13 CN/8000 a=rtpmap:126 telephone-event/8000 a=maxptime:60 a=ssrc:1291334905 cname:ALccmKLk9bGpSGWB a=ssrc:1291334905 msid:itEKr0vXP6lg3KNs4kVau9aL3uAfyWOlItfU 4e8f212e-746a-47bb-bc62-4a42d4e9e84e a=ssrc:1291334905 mslabel:itEKr0vXP6lg3KNs4kVau9aL3uAfyWOlItfU a=ssrc:1291334905 label:4e8f212e-746a-47bb-bc62-4a42d4e9e84e m=video 38359 RTP/SAVPF 100 116 117 96 c=IN IP4 192.168.122.1 a=rtcp:38359 IN IP4 192.168.122.1 a=candidate:4062413514 1 udp 2122260223 192.168.122.1 38359 typ host generation 0 ............ a=candidate:3741779331 2 tcp 1518018303 172.17.42.1 0 typ host tcptype active generation 0 a=ice-ufrag:bwrCv9yS8rCY12Az a=ice-pwd:3k35jpG/i+TCbvBcJPWrw2eP a=ice-options:google-ice a=*fingerprint*:sha-256 52:8C:0F:27:C6:D6:CF:AE:F4:87:AC:AE:DF:7B:9B:B2:75:90:60:6A:2A:82:09:98:AD:04:0B:35:45:6A:13:A2 a=setup:actpass a=mid:video a=extmap:2 urn:ietf:params:rtp-hdrext:toffset a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time a=recvonly a=rtcp-mux 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=rtpmap:116 red/90000 a=rtpmap:117 ulpfec/90000 a=rtpmap:96 rtx/90000 a=fmtp:96 apt=100 Here is SDP received from FreeSwitch in JAIN SIP via UDP: v=0 o=FreeSWITCH 1425524563 1425524564 IN IP4 192.168.131.253 s=FreeSWITCH c=IN IP4 192.168.131.253 t=0 0 m=audio 16390 RTP/AVP 111 0 8 101 13 a=rtpmap:111 opus/48000/2 a=fmtp:111 minptime=10 a=rtpmap:0 PCMU/8000 a=rtpmap:8 PCMA/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-16 a=ptime:20 m=video 16388 RTP/AVP 100 a=rtpmap:100 VP8/90000 I suppose that FreeSwitch wants to see WebRTC connection only on the WebSocket ports and it doesn't know that my UDP client is actually WebRTC client. So I'm wondering if it possible to connect SIP client to the WebSocket port via TCP using standard SIP client and never upgrade connection to WebSocket? Regards, Oleg