[MMUSIC] draft-ejzak-mmusic-data-channel-sdpneg: external rejection of channel

[Christer Holmberg <[e-mail]>]

Hi,

Section 5.2.2 describes what an answerer does when accepting a data channel:

  "The peer receiving such an SDP offer performs the following:

                ...

   o  For accepted data channels, creates peer instances for the data
      channels with the browser using the channel parameters described
      in the SDP offer.  Note that the browser is asked to create data
      channels with stream identifiers not "owned" by the agent."

But, there is no text on rejecting a data channel in the SDP answer.

The answer can of course reject the whole m- line, using port zero in the Answer m- line. But, how does the answerer reject an individual sub-protocol data channel?

Section 5.1.1 says, regarding the SDP dcmap attribute, for accepted data channels:

"This line MUST be replicated without changes in the SDP answer, if
                the answerer accepts the offered data channel."

I guess one way to reject would be to simply not include the dcmap attribute in the Answer, and the Offerer then needs to figure out what was rejected based on the stream values not present in the Answer.

Regards,

Christer