Subject: Two SDP issues

From: Gonzalo Camarillo <[email-masked]>
Date: Thu, 28 Jun 2001 22:01:04 +0300

Hello,

A couple of SDP issues:

1) I recall that we discussed this issue in an IETF meeting, but I am
not aware of the result of the discussion.

Let's say that user A sends an INVITE with two m lines. One for audio
(PCM codec, for instance) and another for DTMF tones.

The receiver (user B), due to any reason, cannot send DTMF tones, but he
can receive them. Can user B add a=recvonly for that m line to the SDP
that he returns in the 200 OK?

2) If I want to stop receiving media (put a call on hold) I send an SDP
with c=0.0.0.0. However, I can still send media. In which address will I
receive RTCP? Should the other party remember my previous c line on
order to send me RTCP?

Regards,

Gonzalo
-- 
Gonzalo Camarillo                    Phone :   +1 212 939 71 71
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From: Paul Kyzivat <[email-masked]>
Date: Thu, 28 Jun 2001 15:26:58 -0400

Interesting questions!

In (2), assume for a moment that your suggestion to remember the
prior c= line for RTCP is adopted. Then what happens if I want to
invite on hold, or accept an invitation on hold? (I believe this
is legal, and I have from time to time seen a call sequence that
did it.)

	Paul Kyzivat
	Cisco Systems

Gonzalo Camarillo wrote:
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