Hi Indresh, Just one small clarification. As the entity behaves as B2B, 18x is sent towards A side with contact header(B2B's address), after receiving 18x without contact header from B side.
Query is that, how the release from A side(as indicated in the picture) to be treated? Or 18x from A side, at first place, should be discarded? Thanks, kumar On Tue, Aug 18, 2009 at 8:04 PM, Singh, Indresh (NSN - US/Boca Raton) < [email protected]> wrote: > Still the figure is not very clear. > > But as Vikram pointed out that contact header is an optional header in > 1xx responses. If no contact header is present in 1xx response then if a > method has to be sent out immediately after this 1xx response ( prior to > receiving another response with contact header ) then the message will > be routed back to the same location where the initial INVITE was sent > out ( assuming no record-route is involved, since you mentioned RR > below. For RR case we need more info as in that case the routing will > happen based on route set built based on RR present in 1xx responses and > also the type of RR LooseRoute or no LooseRoute ). > > Based on your figure below it seems that you rcvd a 18x without contact > and then you rcvd a 18x with contact and then a BYE is being sent by > originator. In that case BYE should be sent based on the latest contact > header information received in 18x header ( if any assuming > Record-Routing is not involved ). > > I also do not think that it is mandatory for the case of even reliable > 18x response as well. I do not think if a 18x response is received > without contact header a PRACK request can not be constructed. Vikram > could you kindly explain why would this be the case as mentioned below > ?? > > >>> a unreliable 18x response without Contact as it is optional. > >>> It is definitely needed in a reliable 18x as without it, a > >>UAC can not > >>> construct a PRACK request. In this case, 18x will timeout and the > >>> early dialog will be terminated. > > Best Regards, > > Indresh K Singh > > >>-----Original Message----- > >>From: [email protected] > >>[mailto:[email protected]] On > >>Behalf Of ext raikkme rrrrr > >>Sent: Tuesday, August 18, 2009 12:27 AM > >>To: [email protected] > >>Subject: Re: [Sip-implementors] 18X response with no Contact Header > >> > >>I tried to translate the picture in notepad. I hope, it is received as > >>intended. Please find below. > >> > >>A > >>side > >>B side > >> ______________ > >>---------------------------------> | B | > >>Invite | > >>|-------------------------------> Invite > >> | > >>|<------------------------------ 100 Trying > >><--------------------------------- | | 18x > >>without contact > >>header > >>100 Trying | 2 > >>|<------------------------------ > >> | | > >><--------------------------------- | | > >>18x with contact | | > >>---------------------------------->| B > >>|---------------------------------> ???????? > >>BYE | | > >> > >> > >>18x from B side received without contact header. 18x response > >>has "To tag" > >>and without Record Route. > >> > >>Thanks, > >>kumar > >> > >> > >> > >>On Mon, Aug 17, 2009 at 11:24 PM, Vikram Chhibber > >><[email protected] > >>> wrote: > >> > >>> We can not see the attachment. A UAC should have no problem > >>processing > >>> a unreliable 18x response without Contact as it is optional. > >>> It is definitely needed in a reliable 18x as without it, a > >>UAC can not > >>> construct a PRACK request. In this case, 18x will timeout and the > >>> early dialog will be terminated. > >>> On Wed, Aug 12, 2009 at 3:03 AM, raikkme > >>rrrrr<[email protected]> > >>> wrote: > >>> > What should be the behaviour, in case 18X response is > >>received with no > >>> > Contact header for the below case? > >>> > > >>> > Please refer the attached document for sample scenario. > >>> > > >>> > The entity is behaving as a B2B, where BYE is received > >>from one side. > >>> > > >>> > Thanks, > >>> > kumar > >>> > > >>> > _______________________________________________ > >>> > Sip-implementors mailing list > >>> > [email protected] > >>> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > >>> > > >>> > >>_______________________________________________ > >>Sip-implementors mailing list > >>[email protected] > >>https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > >> > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
