[OpenSIPS-Users] PRACK interworking requirements

[Bogdan-Andrei Iancu]

agreed, we can look into the UPDATE stuff, but let's take it one at a 
time (as they are not related)... First the PRACK :)

Regards,

Bogdan-Andrei Iancu

OpenSIPS Founder and Developer
   https://www.opensips-solutions.com
   https://www.siphub.com

On 12.01.2026 18:17, Johan De Clercq wrote:
> I think that 200 ok’ing UPDATE also should be added. This seems useful 
> when opensips is used as sbc/b2bua (maybe this can go in 
> topology_hiding.so).
>
> For the rest, I think that your approach is complete.
>
> Verzonden vanuit Outlook voor iOS <https://aka.ms/o0ukef>
> ------------------------------------------------------------------------
> *Van:* Users <users-bounces at lists.opensips.org> namens Bogdan-Andrei 
> Iancu <bogdan at opensips.org>
> *Verzonden:* maandag, januari 12, 2026 5:06 PM
> *Aan:* gmaruzz at opentelecom.it <gmaruzz at opentelecom.it>
> *CC:* OpenSIPS users mailling list <users at lists.opensips.org>
> *Onderwerp:* Re: [OpenSIPS-Users] PRACK interworking requirements
> Hey all and A Happy New Year !
>
> Pocking again the topic.... based on the discussion, I see two 
> approached (they do not exclude one each other):
>
> a) manual - to generate the PRACK explicitly from script, when 
> handling a reply. As Vlad mentioned, maybe something based on 
> dlg_send_sequential() (but tricky when handling multiple branches / 
> to-tags from upstream). Answering to a PRACK can be done even now, so 
> not a problem. Also inserting the related Supported / Requires hdrs, 
> again, can be done from script.
>
> b) auto-mode - to be transparently provided by the dialog module. To 
> be activated by a create_dialog() flag, resulting in auto generating 
> the PRACKs (based on the hdr's in the reply). The module should be 
> also responsible of replying to the PRACK requests and to adjust the 
> hdrs too.
>
> Does this sound like a plan ?
>
> Regards,
> Bogdan-Andrei Iancu
>
> OpenSIPS Founder and Developer
>    https://www.opensips-solutions.com
>    https://www.siphub.com
> On 25.11.2025 13:14, Giovanni Maruzzelli wrote:
>>
>> On Tue, Nov 25, 2025, 11:57 Bogdan-Andrei Iancu <bogdan at opensips.org> 
>> wrote:
>>
>>
>>     The result here should be a dlg dedicated function to generate a
>>     PRACK from the onreply_route, like "dlg_answer_with_prack()" kind
>>     of function? or should we look into a more automatic approach,
>>     like flagging the dialog at creation to automatically generate
>>     the PRACK upon replies flagged with so?
>>
>>
>> personally I'm a control freak and would like better an explicit 
>> function, maybe even with parameters to modify things if needed :))
>>
>> -giovanni
>>
>>
>>
>>
>>
>>
>>     Regards,
>>
>>     Bogdan-Andrei Iancu
>>
>>     OpenSIPS Founder and Developer
>>        https://www.opensips-solutions.com
>>        https://www.siphub.com
>>
>>     On 25.11.2025 11:46, Giovanni Maruzzelli wrote:
>>>     hello OpenSIPSers,
>>>
>>>     in previous mails has been noticed that various ITSPs are
>>>     starting to require PRACK support.
>>>
>>>     We know that PRACK belongs to endpoints, specifically phones and
>>>     B2BUAs.
>>>
>>>     But...
>>>
>>>     There can be a use case where OpenSIPS will work as SBC (not
>>>     necessarily using the b2b module)
>>>
>>>     So, we can have a case where we would like to support that the
>>>     dialogue module insert the 100rel in the Supported: INVITE's
>>>     header, and manage to send a PRACK method to acknowledge
>>>     provisional responses
>>>
>>>     If and when 100rel/PRACK are "generated" by OpenSIPS, they will
>>>     be filtered out (not propagated) to/from the endpoints, even if
>>>     the endpoint would like to support it
>>>
>>>     Reference RFC: https://www.ietf.org/rfc/rfc3262.txt
>>>
>>>     I believe this will be enough to make ITSPs happy.
>>>
>>>     Further developments can be moved to future.
>>>
>>>     Would be very very nice to have this feature backported to
>>>     OpenSIPS 3.6, being it the last of the 3.X series, and an LTS
>>>
>>>     Please let's gather here your thoughts , requests, corrections
>>>     and observations on this issue.
>>>
>>>     Have a nice Monday you all!
>>>
>>>     -giovanni
>>>
>>>     -- 
>>>     Sincerely,
>>>
>>>     Giovanni Maruzzelli
>>>     OpenTelecom.IT
>>>     cell: +39 347 266 56 18
>>>
>>>
>>>     _______________________________________________
>>>     Users mailing list
>>>     Users at lists.opensips.org
>>>     http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>
>
>
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