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<font face="monospace">Hi all,<br>
<br>
Just to add some info about the OpenSIPS internals, when comes to
building the CANCEL request. It will use exactly the same TO/FROM
hdrs as the ones sent into the INVITE request.<br>
<br>
The CANCEL request works at transactional level - it shares the
same VIA branch and stuff as the INVITE branch it cancels. So the
tag info (which is at dialog level) is irrelevant, as again, the
canceling happens at transactional level.<br>
<br>
Even more, if we consider the proxy may do parallel forking - in
this case the UAC may receive multiple 1xx replies, with different
to-tags... So, following the CISCO approach, which tag the UAC
should use in order to cancel the call ?? <br>
<br>
Regards,<br>
</font>
<pre class="moz-signature" cols="72">Bogdan-Andrei Iancu
OpenSIPS Founder and Developer
<a class="moz-txt-link-freetext" href="https://www.opensips-solutions.com">https://www.opensips-solutions.com</a>
<a class="moz-txt-link-freetext" href="https://www.siphub.com">https://www.siphub.com</a></pre>
<div class="moz-cite-prefix">On 17.11.2024 23:20, nz deals wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CALOQYisnsDM+2bTu1nEp3kALAuELAG70-npUfxnAhddLafsOZA@mail.gmail.com">
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<p>Hi Community</p>
<p>I’m encountering a strange issue with <code>CANCEL</code>
requests in my opensips 3.4.2 setup. Here’s the scenario:</p>
<ol>
<li>My carrier sends the initial <code>INVITE</code> without
a <code>tag</code> in the <code>To</code> header, which I
forward to a Cisco phone.</li>
<li>The Cisco phone responds with a <code>180 Ringing</code>
message, which includes a <code>tag</code> in the <code>To</code>
header.</li>
<li>When I send a <code>CANCEL</code> request, my carrier
does not include the <code>tag</code> in the <code>To</code>
header, and as a result, OpenSIPS also forwards the <code>CANCEL</code>
to the Cisco phone without the <code>tag</code>.</li>
</ol>
<p>Because of this, the Cisco phone responds with a <code>481
Call/Transaction Does Not Exist</code> error, and the call
remains active on the phone without being canceled.</p>
<p>I’ve tried modifying the <code>CANCEL</code> request to
include the <code>tag</code> in the <code>To</code> header,
but I wasn’t able to modify because the initial <code>INVITE</code>
doesn’t have a <code>tag</code> in the <code>To</code>
header.</p>
<p>Has anyone experienced a similar issue or found a way to fix
this? Any guidance would be greatly appreciated.</p>
<div><br>
</div>
<div>Thanks</div>
<div><br>
</div>
<div>Regards,</div>
<div>Jason</div>
</div>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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</pre>
</blockquote>
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