a=rtpmap:102 L16/24000
a=rtpmap:103 opus/48000/2
a=fmtp:103 useinbandfec=1; maxaveragebitrate=24000; maxplaybackrate=24000; ptime=20; minptime=10; maxptime=40
a=rtpmap:104 telephone-event/24000
a=fmtp:104 0-16
a=rtpmap:105 CN/24000
a=rtpmap:106 telephone-event/48000
a=fmtp:106 0-16
a=rtpmap:107 CN/48000