title: Understanding SDP generated by WebRTC
body: <p>I went to chrome://webrtc-internals/ to copy the sdp. Overall, I'd like to understand the meaning.</p>
  
  <pre><code>setRemoteDescription
  
  type: answer, sdp: v=0
  o=mozilla...THIS_IS_SDPARTA-39.0 6618245136742574887 0 IN IP4 0.0.0.0
  s=-
  t=0 0
  a=fingerprint:sha-256 27:8B:F6:1A:72:47:17:2B:23:C1:9A:85:AB:3A:E0:29:15:B9:F5:B0:B6:EA:17:C9:11:99:AA:B7:AB:45:A9:60
  a=ice-options:trickle
  a=msid-semantic:WMS *
  m=application 9 DTLS/SCTP 5000
  c=IN IP4 0.0.0.0
  a=sendrecv
  a=ice-pwd:a33017ce6eae687d1afdae61c9f0db55
  a=ice-ufrag:f8acf035
  a=mid:data
  a=sctpmap:5000 webrtc-datachannel 256
  a=setup:active
  </code></pre>
  
  <p>Specifically, I'd like the understand the meaning of </p>
  
  <pre><code>a=sctpmap:5000 webrtc-datachannel 256
  </code></pre>