[SR-Users] Via header branch parameter in ACK message not unique

[Phillman25 Kyriacou]

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 at 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 -- http://www.asipto.comhttp://linkedin.com/in/miconda -- http://twitter.com/miconda
>
>
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