[MMUSIC] How does an answerer reject the first m line in a BUNDLE?

"Ejzak, Richard P (Richard)" <richard.ejzak@alcatel-lucent.com> Mon, 25 February 2013 15:52 UTC

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From: "Ejzak, Richard P (Richard)" <richard.ejzak@alcatel-lucent.com>
To: Christer Holmberg <christer.holmberg@ericsson.com>, "mmusic@ietf.org" <mmusic@ietf.org>
Thread-Topic: How does an answerer reject the first m line in a BUNDLE?
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Date: Mon, 25 Feb 2013 15:52:00 +0000
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Subject: [MMUSIC] How does an answerer reject the first m line in a BUNDLE?
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Hi Christer,
In rereading your latest BUNDLE draft I was confused about what the answerer does when it needs to reject the first m line in a bundle group.  The following text in your draft implies to me that the answerer is not allowed to reject the first m line:


"Until the SDP Answerer receives the new SDP Offer, which contains an

   identical port number value for each "m=" line associated with a

   "BUNDLE" group, it MUST use the port, and related information (ICE

   candidates, SDES keys etc) associated with the first "m=" line in the

   "BUNDLE" group."

What does this text mean if the answerer rejects the first line?  Doesn't this mean that the answerer must wait for the "new" SDP offer with identical ports for each group member before it knows the 5-tuple to use for the bundle, thus delaying call setup?  What does it mean to use SDES keys for a rejected m line (since these keys should only apply to this m line).

It may not be common to reject the first line but I think we have to allow for it.

BR, Richard