[SR-Users] Dialog - timeout for dlg with CallID

[Julien Chavanton]

It seems I found the problem and I have a fix.

The root cause is probably that the locally generated 408 is not updating
the dialog to-tag.

However, always checking for a to-tag match, before a non to-tag match will
fix any such issue.

I will prepare a merge request on Monday to start discussing the option
always matching to-tag first.

On Fri, Sep 25, 2020 at 11:27 AM Julien Chavanton <jchavanton at gmail.com>
wrote:

> I did catch the logs, and after looking at the trace, it seems like dialog
> mismatch with a serial forking scenario :
>
> - log line 3 is telling us that a NO-ACK disconnection should be triggered
> - log line 1-2 is telling us what happened when the ACK was received in
> dlg_onroute(), oddly enough state 5 was old and new, could it be a
> mismatch/confusio with the previous dialog, looking in this direction ...
>
> 1: 2020-09-25T16:30:16.896: dialog [dlg_handlers.c:1273]:
> extra_ack_debug_info(): [ACK][1] state not changed >>>
> call-id[562419_125824138_2072238224] to-tag[<sip:+14019991904 at anon.com
> >;tag=gK02b68836]
> 2: 2020-09-25T16:30:16.896: dialog [dlg_handlers.c:1440]: dlg_onroute():
> [ACK] state not changed old[5]new[5]
> ...
> 3: 2020-09-25T16:32:22.674: dialog [dlg_hash.c:247]: dlg_clean_run():
> dialog disconnection no-ACK
> call-id[562419_125824138_2072238224][1601051416]<[1601051542 - 60]
>
>
> After looking at the pcap trace, call-id 562419_125824138_2072238224 was
> involved in serial forking :
>
> call attempt #1
>
> X >> INVITE >> Y   // no to-tag
> X << 100
> ...
> X << 408           // to-tag=594d50c3218065a60bb91fd47a70fbc1-59edef02
> (locally generated)
> X >> ACK           // to-tag=594d50c3218065a60bb91fd47a70fbc1-59edef02
>
> call attempt #2
>
> X >> INVITE >> Z   // no to-tag
> X << 100
> X << 200    << Z   // to-tag=gK02b68836
> X >> ACK    >> Z   // to-tag=gK02b68836 (Should be state old[3]new[4], I
> wonder how it could possibly be state old[5]new[5])
>
>
>
> I did look at several occurrences and there is always a locally generated
> 408/to-tag before, seems like I have a good lead to investigate further.
>
>
>
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