title: SDP for FFMPEG (IP addresses)
body: <p>I'm receiving audio via RTP, so I'm opening input from the SDP I generate. 
  Media is coming from <code>Port_sender</code>, <code>IP_sender</code>. IP and port of the server for listening: <code>IP_server</code>, <code>Port_server</code>. Here is my SDP template. What of <code>{Port_sender, IP_sender, IP_server, Port_server}</code> should I put in <code>{%1%, %2%, %3%}</code> for the SDP that I feed to ffmpeg and for the SDP that I give back to the sender?</p>
  
  <pre><code>\n\nv=0\n
  o=- 0 0 IN IP4 %1%\n
  s=name\n
  c=IN IP4 %2%\n
  t=0 0\n
  a=tool:libavformat 57.3.100\n
  m=audio %3% RTP/AVP 97\n
  b=AS:705\n
  a=rtpmap:97 PCMU/44100/2\n"
  </code></pre>
  
  <p>Debugging it from different IPs is hard for me now. But from one computer it works perfectly.</p>