[SR-Users] Should I ignore Route header in ACK?

[Alex Balashov]

Well, that was a confusing statement. To clarify: 

Record-Route imposes obligations on both UAs to send their in-dialog
requests through an intermediate proxy hop. The callee will do this
because the intermediate proxy added a Record-Route to the INVITE before
passing it to the callee, and the caller will do it because the same
Record-Route is copied into the 2xx response by the callee so that the
caller knows about it. If any of these things are not happening, that
could be the reason.

On Sun, Jul 01, 2018 at 10:50:45AM +0300, Yuriy Gorlichenko wrote:

> Alex thank you for the response
> So all that I found is correct and known looks like correct.
> Then last question confusing me - why some UAC's ignoring it.
> Looks like they are just have not full RFC interpretation but as i beleive
> FreeSwitch have good SIP binding with almost full RFC compatable
> 
> question is: Any guess why this can happen?
> Because on my side - when kamailio as one more proxy between porvider and
> UAC all works correctly (means kamailio not ignores Route header and it is
> right behaivor).
> Looks like this happens when only 1 Request route arrives at the response
> from UAS...
> 
> 2018-07-01 10:28 GMT+03:00 Alex Balashov <abalashov at evaristesys.com>:
> 
> > Hi,
> >
> > Record-Route from the UAS in the 2xx response to the initial INVITE
> > transaction should be recast a Route set in in-dialog messages
> > originating from the caller, of which an end-to-end ACK is one.
> >
> > The next Route header should be followed for reaching the next hop on the
> > network and transport level. The request URI should cosmetically be
> > equivalent to the Contact URI of the far end, but the Route header will
> > cause a deviation in where the request is actually sent.
> >
> > This is entirely appropriate and correct. Nobody should be ignoring a
> > Route header.
> >
> > -- Alex
> >
> > On Sun, Jul 01, 2018 at 10:27:00AM +0300, Yuriy Gorlichenko wrote:
> >
> > > Hi
> > > I know that this is not question too much close to the kamialio users but
> > > mostly losed to the RFC specifiacations but this community looks like
> > > pretty much close to it that is why I want to ask this question here,
> > > that's why sorry and thanks for help in this question:
> > >
> > > I have a situation when provider sends me 200 response with Request-Route
> > > header and changed contact header:
> > >
> > > Means response comes from
> > > 1.1.1.1:5060
> > > Request-Route contains:
> > > 1.1.1.1:5060
> > > But Contact contains:
> > > 1.1.1.1:5061
> > >
> > > My ACK (handled by kamailio) goes to the 1.1.1.1:5060 as it setted up at
> > > the Route Hedaer of ACK (because of Request-Route)
> > >
> > > but provider says me that i should use Contact for the ACK
> > >
> > >
> > > I was surprised because of
> > > https://tools.ietf.org/html/rfc3261#section-12.2.1.1
> > > and
> > > https://tools.ietf.org/html/rfc3261#section-8.1.2
> > >
> > > Says that I should use Route header for reaching destination
> > > But I was surprised second time when tested this scenario with FreeSwitch
> > > and another softphone (as UA) because of it both sends ACK to the based
> > on
> > > Contact address and ignores Route
> > >
> > > I just wanna ask if I missed some scenario in the RFC when it is
> > described
> > > to ignore Route header for the UA
> > >
> > > (I know that I use kamailio on my case as proxy server but should
> > > understand finally who should make changes with packet handling)
> > >
> > > Thanks one more time for the resonses and sorry one more time for the
> > goal
> > > of this question that belongs to the kamailio just partially
> >
> > > _______________________________________________
> > > Kamailio (SER) - Users Mailing List
> > > sr-users at lists.kamailio.org
> > > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> >
> >
> > --
> > Alex Balashov | Principal | Evariste Systems LLC
> >
> > Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free)
> > Web: http://www.evaristesys.com/, http://www.csrpswitch.com/
> >
> > _______________________________________________
> > Kamailio (SER) - Users Mailing List
> > sr-users at lists.kamailio.org
> > https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users
> >

> _______________________________________________
> Kamailio (SER) - Users Mailing List
> sr-users at lists.kamailio.org
> https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users


-- 
Alex Balashov | Principal | Evariste Systems LLC

Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) 
Web: http://www.evaristesys.com/, http://www.csrpswitch.com/