Re: [rtcweb] I-D Action: draft-alvestrand-one-rtp-00.txt

Ross Finlayson <finlayson@live555.com> Fri, 12 August 2011 03:36 UTC

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Date: Thu, 11 Aug 2011 20:37:08 -0700
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Subject: Re: [rtcweb] I-D Action: draft-alvestrand-one-rtp-00.txt
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Thanks, Harald, for this submission.

A nit (I think).  Unless I'm misunderstanding the purpose of the "a=group:TOGETHER" attribute, the port numbers in the two example 'answers' are wrong.

Example 1:
  Answer, from an entity that understands TOGETHER

         v=0
         o=bob 2808844564 2808844564 IN IP4 host.biloxi.example.com
         s=
         c=IN IP4 host.biloxi.example.com
         t=0 0
         a=group:TOGETHER foo bar
         m=audio 49174 RTP/AVP 0
         a=mid:foo
         b=AS:200
         a=rtpmap:0 PCMU/8000
         m=video 49170 RTP/AVP 32
         a=mid:bar
         b=AS:1000
         a=rtpmap:32 MPV/90000
Should be (I think):
         ...
         a=group:TOGETHER foo bar
         m=audio 49170 RTP/AVP 0
         a=mid:foo
         b=AS:200
         a=rtpmap:0 PCMU/8000
         m=video 49170 RTP/AVP 32
         a=mid:bar
         b=AS:1000
         a=rtpmap:32 MPV/90000

Example 2:
   Answer, from an entity that understands grouping, but does not
   understand TOGETHER

         v=0
         o=bob 2808844564 2808844564 IN IP4 host.biloxi.example.com
         s=
         c=IN IP4 host.biloxi.example.com
         t=0 0
         m=audio 49174 RTP/AVP 0
         a=mid:foo
         a=rtpmap:0 PCMU/8000
         b=AS:200
         m=video 49170 RTP/AVP 32
         a=mid:bar
         a=rtpmap:32 MPV/90000
         b=AS:1000
Should be (I think):
         ...
         m=audio 49170 RTP/AVP 0
         a=mid:foo
         a=rtpmap:0 PCMU/8000
         b=AS:200
         m=video 51372 RTP/AVP 32
         a=mid:bar
         a=rtpmap:32 MPV/90000
         b=AS:1000


Ross Finlayson
Live Networks, Inc.
http://www.live555.com/