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<p><font size="-1">Hello All, I have an issue for which I have not
been able to find a definitive answer in the RFCs.</font></p>
<p><font size="-1">I use RTPProxy as part of NAT traversal so RTP
streams are set up between upstream provider and my proxy, and
between my proxy and the UAC.</font></p>
<p><font size="-1">The problem I have, is UAC changes it's RTP port
between 183 and 200 OK and thus increments the SDP version
number, BUT the ports DO NOT change between proxy and upstream
provider but the SDP version number does, because it is passed
through. The upstream provider says this violates RFC 4566 and
sends an immediate BYE after the final ACK.</font></p>
<p><font size="-1">I read that RFC 4566 says: <br>
</font></p>
<p><font size="-1">" <i><sess-version> is a version number
for this session description. Its</i><i><br>
</i><i> usage is up to the creating tool, so long as
<sess-version> is</i><i><br>
</i><i> increased when a modification is made to the
session data. Again,</i><i><br>
</i><i> it is RECOMMENDED that an NTP format timestamp is
used</i>."</font></p>
<p><font size="-1">The problem is I can't find an RFC stating "You
MUST NOT increment<br>
version number if no change is made to the SDP".</font></p>
<p><font size="-1">So I must either: <br>
</font></p>
<p><font size="-1">1. Prove that it should be OK to increment the
version number without any change to the SDP. Or</font></p>
<p><font size="-1">2. Find a way of not passing through the
incremented version number to the upstream side where the SDP
has not actually changed.</font></p>
<p><font size="-1">I hope that makes sense... As always any help
very nuch appreciated.</font><br>
</p>
<div class="moz-signature"><font size="-1"><font face="Verdana">Kind
regards,<br>
<br>
Adrian Fretwell<br>
Nottinghamshire<br>
UK<br>
</font></font>
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