Dear Daniel
Thanks, this worked!
I will inform my carrier that they are handling the ACK 200 message wrong.
just one question: the syn_branch=0 is used for only stateless ACK messages?
Thanks again for your assistance!
Phillip
On Mon, Dec 12, 2011 at 11:25 AM, Daniel-Constantin Mierla <
miconda(a)gmail.com> wrote:
Hello,
On 12/12/11 8:18 AM, Phillman25 Kyriacou wrote:
Dear List
I'm currently facing an issue with a carrier whereby they are complaining
that the via header branch parameter (sip.Via.branch == "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?
set in your config file the global parameter:
syn_branch=0
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).
Cheers,
Daniel
--
Daniel-Constantin Mierla --
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