Paul is spot on here - the reason B2BUA was so loosely defined was so that implementations have license to do whatever they want, within the general guidelines for SIP. So ask yourself, should all headers be copied - Are they needed further down the down chain? If so then yes definitely. People get too bogged down trying to debate exactly what a B2BUA is and what it should achieve - As long as it serves the purpose it was designed for + is compliant to the SIP specification, then it is correct behavior.
Chris. >-----Original Message----- >From: Paul Kyzivat [mailto:[EMAIL PROTECTED] >Sent: 02 October 2003 14:58 >To: Andreas Bystr�m >Cc: Sip Implemators >Subject: Re: [Sip-implementors] Questions about being b2b > >Andreas, > >There really isn't any single answer to your questions that is >applicable to all B2BUAs in the situation you describe. The answers >depend on what your B2BUA is trying to achieve. > >For instance, it could be that it is trying to be a "transparent" B2BUA, >being almost as unobtrusive as a proxy, but reserving the right to send >a BYE to both sides. > >Or, it could be that the B2BUA is operated on behalf of B's user. E.g. >Perhaps B is a particularly stupid 2543 compatible phone, and the B2BUA >is being used as a frontend for it, to enhance it for compatibility with >3261, to add security, etc. > >Or, the B2BUA could be at the boundary of a service provider domain, >enforcing all sorts of rules for the domain. > >Each of these is likely to result in different answers to your >questions. If you can precisely define your objectives, then people may >be able to help you answer the questions. But probably by the time you >have done that you will be able to answer them yourself. > > Paul > >Andreas Bystr�m wrote: >> Hi all, >> >> I have some questions about how a B2B should behave. >> The scenario is : A - proxy 1 - B2B - proxy 2 - B >> >> 1) Should all fields be kept from the incoming request to the new request >> sent out (in the B2B). I will remove (or change) via-list, call-id, >> record-route and contact. All other headers, should they be kept? As an >> example we can take the User-Agent sent from A via proxies and B2B to B. >> >> 2) When B sends BYE, is the B2B supposed to answer with 200 OK or sould >it >> forward the BYE first and wait for a 200 OK from A before it sends the >200 >> OK back to B >> >> And in the end a short question about 407 authentication. If A sends >Invite >> to a proxy where it has to authenticate itself, is it OK or not OK for >the >> proxy to first send 100 Trying and then send 407? As I understand it, it >is >> OK according to the RFC since the first is a provisional response and the >> second a final response. Just want to check with you since I have never >seen >> this behavior before. >> >> Thanks in advance! >> >> // Andreas >> >> _______________________________________________ >> Sip-implementors mailing list >> [EMAIL PROTECTED] >> http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors >> > >_______________________________________________ >Sip-implementors mailing list >[EMAIL PROTECTED] >http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
