[OpenSIPS-Users] Is it possible to Reject 200OK

[Alex A]

Thank you for all the pointers, Donat

On Dec 2, 2020, 5:10 AM, at 5:10 AM, Donat Zenichev <donat.zenichev at gmail.com> wrote:
>Hello Alex.
>Firstly I would like to mention that t_on_failure() is only to be used
>when
>either of this is true:
>- receiving of a negative reply that completes the transaction ;
>- generation of a negative reply that completes the transaction ;
>
>From the article given by the OpenSIPS team:
>"It contains a set of actions to be taken each transaction that
>received
>only negative replies (>=300) for all branches."
>Please see: https://www.opensips.org/Documentation/Script-Routes-3-0
>
>So that, the "with ACK+BYE combination" as you mentioned, will not be
>considered as a negative reply, that leads to a transaction ending.
>
>Now getting back to the original question.
>Quotation: "Assuming that there are lines in SDP that are not
>desirable. IS
>there any legal way to reject this call before it's answered from
>Opensips
>side . . . ".
>
>It looks a bit strict-forward to drop the media session right away, if
>you
>see non-desirable SDP attributes.
>
>I would first of all try to read this section
>https://tools.ietf.org/html/rfc6337#section-2.2 of RFC 6337,
>that defined at least 4 possible scenarios for SDP negotiations.
>What I mean to say, is that there might be a way to manage SDP session,
>suppressing your carrier to use desired media attributes.
>Still I want to underline "might be".
>
>If SDP protocol allows us to negotiate parameters of the media session
>during the whole handshake sequence: INVITE -> 200OK -> ACK
>Even though the scenarios are already predefined, you might try to let
>ACK
>have an SDP body to list needed attributes one more time.
>Still this might be not working, since in the RFC 6337, you can see
>this
>definition:
>"The answer cannot be updated, and a new offer cannot be sent in a
>subsequent reliable response for the same INVITE transaction."
>
>So you might try to look into the following:
>- INVITE (from your OpenSIPS instance) - sends SDP offer
>- 183 provisional response / 200 OK - received from a carrier with SDP
>answer
>- at this point you consider all the attributes for a desired media and
>send ACK containing SDP body with the very last list of desired
>parameters.
>
>Again, this is just an idea which was never used in the practice.
>I hope you will find my answer useful :)
>
>
>
>
>
>On Tue, Dec 1, 2020 at 7:08 PM Alex A <alex.a at gtanetworkconsulting.com>
>wrote:
>
>> Hi,
>>
>> I have been trying to find a solution for a particular scenario:
>>
>> Opensips sends INVITE to a carrier
>> Carrier responds 180 Ringing (no SDP)
>> Carrier responds 200OK with SDP
>>
>> Assuming that there are lines in SDP that are not desirable:
>>
>> a) IS there any legal way to reject this call before it's answered
>from
>> Opensips side (with ACK+BYE combination)
>> b) in case, it possible - will the call proceed into t_on_failure
>block in
>> this case?
>>
>>
>> Thank you greatly in advance.
>>
>>
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users at lists.opensips.org
>> http://lists.opensips.org/cgi-bin/mailman/listinfo/users
>>
>
>
>-- 
>
>Best regards,
>Donat Zenichev
>
>
>------------------------------------------------------------------------
>
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