[SR-Users] SIP RFC behaviour for 180/200 to_tag mismatch

[Daniel-Constantin Mierla]

Hello,


On 06.03.18 17:24, Mititelu Stefan wrote:
> Hi people,
>
> I am trying to search for the RFC behavior in case of 180/200 to tag
> mismatch of an INVITE. From my readings so far, I'm not 100% convinced
> of the correct behavior.
>
> However, there may be a scenario, where this might be plausible:
> 1. parallel forked two calls
> 2. 180 ringing comes for first one, but not for second one(various
> reasons)
> 3. 200 ok comes for second one
>
> Any opinions about this? Do you have some references that will make
> this 100% clear?
>
the UA has to take the tag from 200ok. Provisional responses are not
mandatory, one can just send directly 200ok. Different tags can come due
to serial or parallel forking, the the UA must be prepared to handle
branches of its call until the 200ok is received and then use it to
complete the dialog.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla
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