[SR-Users] SIP contact header question

[Jack Davis]

Thank you all for the replies.


I'm already utilizing a record-route header in the initial Invite before
any re-invites occur.

Is the preferred method to also include a record-route header in the 200 OK
that is given in response to the re-invite?

Thank you,
Jack Davis

On Fri, Mar 3, 2017 at 2:14 PM, Emmanuel BUU <emmanuel.buu at ives.fr> wrote:

> For a SIP proxy, the preferred method is indeed to add a Record-Route
>
> In the script, add record_route(); instruction.
>
> Emmanuel
> IVèS
>
>
>
> Le 2017-03-02 à 20:03, Robert Johnson a écrit :
>
>> I seem to recall reading something stating that you shouldn't modify the
>> contact header - But, I can't find the text.
>>
>> Might suggest adding a Record-Route header instead of re-writing the
>> contact header?
>>
>> I'm curious as to what the list has to say about this question, I've
>> considered doing the same thing.
>>
>> On 03/02/2017 04:53 PM, Jack Davis wrote:
>>
>>> Greetings,
>>>
>>> I have a general question about the usage of SIP contact headers in the
>>> context of using Kamailio as a SIP proxy.
>>>
>>>
>>> ________________________________
>>>
>>> [  A  ] --> [  Kamailio  B ]  ---> [  C ]
>>>
>>> Node A originates a SIP invite, containing a valid via header and URI
>>> while setting the contact address to a user at itself and delivers it to
>>> Kamailio B which is acting as a SIP proxy.
>>>
>>> Kamailio B then uses dispatcher routing to direct the Invite to node C,
>>> adding a via line with its own information as well as a record-route
>>> header with its own proxy information but retaining the same contact
>>> address from A.
>>>
>>> Node C establishes the call and then sends a re-invite to the Kamailio B
>>> proxy which is in turn sent to Node A. Node A responds with a 200 OK
>>>
>>> The problem arises when Node C tries to send an Ack in response to this
>>> 200 OK. The ack is being sent to the Contact address, rather than the
>>> routing already established in the initial dialog.
>>>
>>> ________________________________
>>>
>>> My question is: should kamailio be rewriting this contact address with
>>> its own? Is that the best practice? My understanding is that the contact
>>> header is more so related to future requests within the same dialog ONLY
>>> when a record-route is not used.
>>>
>>> I would appreciate any clarification on the RFC or best practices in
>>> this scenario.
>>>
>>> Thank you,
>>> Jack Davis
>>>
>>>
>>> _______________________________________________
>>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>>> sr-users at lists.sip-router.org
>>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>>
>>>
>> _______________________________________________
>> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
>> sr-users at lists.sip-router.org
>> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>>
>
>
> _______________________________________________
> SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list
> sr-users at lists.sip-router.org
> http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.sip-router.org/pipermail/sr-users/attachments/20170303/180e3153/attachment.html>