On Fri, Dec 12, 2008 at 10:24 PM, kaiduan xie <[email protected]> wrote: > But how B2BUA generates SDP answer to be carried in PRACK? >
Can replay the previously played SDP > > > ----- Original Message ---- > From: Neelakantan Balasubramanian <[email protected]> > To: kaiduan xie <[email protected]>; "[email protected]" > <[email protected]> > Sent: Friday, December 12, 2008 8:18:46 PM > Subject: RE: [Sip-implementors] PRAC/B2BUA > > See below. > >> -----Original Message----- >> From: [email protected] [mailto:sip- >> [email protected]] On Behalf Of kaiduan xie >> Sent: Friday, December 12, 2008 6:28 PM >> To: [email protected] >> Subject: [Sip-implementors] PRAC/B2BUA >> >> Hi, all, >> >> An inter-operation problem is encountered, the scenario is, >> >> UA 1 B2BUA GW >> | INVITE-1 | | >> |-------------------->| INVITE-2 | >> | |----------------------->| >> | | 183-3 | >> | |<----------------------| >> | 183-4 | | >> |<--------------------| 183-5 | >> | |<----------------------| >> >> INVITE-1 does not have SDP, and no Supported header. >> INVITE-2 does not have SDP, but INVITE-2 has Supported header with >> 100rel. >> 183-3 has SDP, and Required header with 100rel. 183-3 is re- >> transmitted in 183-5. I omits further retransmission. >> 183-4 has SDP, but no Required header. >> >> The call fails. >> >> My question is: is legal for B2BUA to put Supported header with 100rel >> if UA1 indicates that it does not support 100rel? I think B2BUA is >> wrong in this case. > > [Neelakantan Balasubramanian] > B2BUA can provide different behavior on two legs of the call. There is no > requirement on what B2BUA should do, as for UA1, the B2BUA is the UAS. There > is no 100rel supported on this leg of the call. For GW, the B2BUA is the > UAC. In this leg 100rel is supported. > > So, the B2BUA should handle retransmits of 183, send the PRACK for each > provisional responses. > [Neelakantan Balasubramanian] > >> >> In the above picture, B2BUA is from a very big company :) > > [Neelakantan Balasubramanian] > You should talk with the vendor. > >> >> What is your point? >> >> Thanks >> >> kaiduan >> > > > > __________________________________________________________________ > Looking for the perfect gift? Give the gift of Flickr! > > http://www.flickr.com/gift/ > _______________________________________________ > Sip-implementors mailing list > [email protected] > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > -- M. Ranganathan _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
