[OpenSIPS-Users] Incorrect callid in ACK

[Mark Farmer]

I have confirmed that the Call-ID header is in fact incorrect regardless of
what sngrep tells me by logging the message buffer for ACK's.
The call flows like this:

Provider -> 1st OpenSIPS -> 2nd OpenSIPS -> Teams

What seems to be happening is that the ACK comes from provider to 1st
OpenSIPS and when routed to 2nd OpenSIPS it is sent with the original
Call-ID created by provider instead of than the one generated by
topology_hiding(UC) for the original INVITE which results in:
WARNING:dialog:dlg_onroute: tight matching failed for ACK with
callid='54303148.....etc'

I doubt this is a bug, more likely something I'm doing wrong. Does anyone
have any ideas please?

Many thanks!
Mark.



On Tue, 8 Jun 2021 at 16:56, Mark Farmer <farmorg at gmail.com> wrote:

> Thanks for the reply John!
>
> Checking things over, the tags look fine.
>
> According to the logs the ACK is being forwarded with the original Call-ID
> header.
> It seems to arrive at the next hop as having been encrypted by
> topology_hiding() but in the log of that next hop I get a match failure
> because the original header doesn't match what's in the existing dialog.
>
> WARNING:dialog:dlg_onroute: tight matching failed for ACK with callid='
> 42284230-3832136123-249469431 at sbc-uk-l-far07b.uk.sdin.bt.net'/60,
> ftag='3832136123-1536789624'/21, ttag='2e31e1179f3440fca8aed29db28c4314'/32
> and direction=0
> WARNING:dialog:dlg_onroute: dialog identification elements are
> callid='DLGCH_e0JXVmd7Y2NiQ11dYXhjZX5CVkNhfWlneUlRXWIJIzEsXRAFfiV9NS4CVVkxZyU4YQMBBz1nMidhHgAa'/86,
> caller tag='3832136123-1536789624'/21, callee
> tag='2e31e1179f3440fca8aed29db28c4314'/32
>
> But according to sngrep the ACK arrives with the correct Call-ID header:
>
> Call-ID:
> DLGCH_e0JXVmd7Y2NiQ11dYXhjZX5CVkNhfWlneUlRXWIJIzEsXRAFfiV9NS4CVVkxZyU4YQMBBz1nMidhHgAa
>
> So I don't know which to believe at this point.
>
> Mark.
>
>
> On Tue, 8 Jun 2021 at 13:58, John Quick <john.quick at smartvox.co.uk> wrote:
>
>> Mark,
>>
>> I wasn't using topology hiding, but had a problem similar to this which
>> baffled me for a long time until I noticed that the To-tag value wasn't
>> matching the value in the "200 OK". Looking at the DBG logs, it appears
>> that
>> the dialog matching uses To-tag and From-tag.
>>
>> Another idea - topology hiding puts a unique hash code into the Contact
>> header. Is that getting altered by a downstream server?
>>
>> Compare the "200 OK" elements with the equivalent ACK elements. Hope this
>> helps.
>>
>> John Quick
>> Smartvox Limited
>>
>>
>>
>
> --
> Mark Farmer
> farmorg at gmail.com
>


-- 
Mark Farmer
farmorg at gmail.com
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