Dear Daniel<br><br>Thanks, this worked!<br>I will inform my carrier that they are handling the ACK 200 message wrong.<br>just one question: the syn_branch=0 is used for only stateless ACK messages?<br><br>Thanks again for your assistance!<br>
Phillip<br><br><br><div class="gmail_quote">On Mon, Dec 12, 2011 at 11:25 AM, Daniel-Constantin Mierla <span dir="ltr"><<a href="mailto:miconda@gmail.com">miconda@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Hello,<div class="im"><br>
<br>
<br>
On 12/12/11 8:18 AM, Phillman25 Kyriacou wrote:
<blockquote type="cite"><span style="color:rgb(0,0,0)">Dear List</span><br style="color:rgb(0,0,0)">
<br style="color:rgb(0,0,0)">
<span style="color:rgb(0,0,0)">I'm currently facing an issue with
a carrier whereby they are complaining that the via header
branch parameter (sip.Via.branch == "</span><span style="font-size:11pt;font-family:"Arial","sans-serif";color:rgb(0,51,255)"><span style="color:rgb(0,0,0)">z9hG4bKcydzigwkX") in
the ACK messages is not unique which results in some calls
being successful and some terminating after 20 seconds as
their sip proxy determines it as a duplicate request. Is there
a way to make the via header branch parameter in the ACK
message unique across every transaction?<br>
</span></span></blockquote></div>
set in your config file the global parameter:<br>
<br>
syn_branch=0<br>
<br>
On the other hand, the behavior of the devises used by carrier is
completely broken. ACK can have a different path than INVITE, so
there should be no match done on Via branch parameter. Since it is
ACK for 200OK, it has to be matched for dialog. Having the RFC3261
cookie in the branch parameter, it has to be matched with (callid,
from tag, to tag).<br>
<br>
Cheers,<br>
Daniel<br><font color="#888888">
<pre cols="72">--
Daniel-Constantin Mierla -- <a href="http://www.asipto.com" target="_blank">http://www.asipto.com</a>
<a href="http://linkedin.com/in/miconda" target="_blank">http://linkedin.com/in/miconda</a> -- <a href="http://twitter.com/miconda" target="_blank">http://twitter.com/miconda</a></pre>
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</blockquote></div><br>