Robert, Due to historic reason, our product was initially only a strict-router, it was later added the functionality to be a loose-router, But many our customer's deployment is still strict-router, I think it's necessary to clarify this inconsistence, though I do not see the immediate pain on this issue.
Thanks a lot Regards, -Rockson -----Original Message----- From: Robert Sparks [mailto:[EMAIL PROTECTED] Sent: Monday, August 18, 2008 11:36 PM To: Rockson Li (zhengyli) Cc: [email protected] Subject: Re: [Sip-implementors] Can proxy forward a req to a local determined strict-router? On Aug 16, 2008, at 10:58 AM, Rockson Li (zhengyli) wrote: > Hi folks, > > RFC3261 > sec 16.6 Request Forwarding > > 6. Postprocess routing information > > If the proxy has a local policy that mandates that the request > visit one specific proxy, an alternative to pushing a Route > value into the Route header field is to bypass the forwarding > logic of item 10 below, and instead just send the request to > the address, port, and transport for that specific proxy. If > the request has a Route header field, this alternative MUST > NOT > be used unless it is known that next hop proxy is a loose > router. Otherwise, this approach MAY be used, > > so I think this means if the request contains no Router header, this > request might be forwarded to a next element - either a strict-router > or > loose-router- directly without > adding Route header. > > However, the next sub section > > 7. Determine Next-Hop Address, Port, and Transport > > The proxy MAY have a local policy to send the request to a > specific IP address, port, and transport, independent of the > values of the Route and Request-URI. Such a policy MUST NOT > be > used if the proxy is not certain that the IP address, port, > and > transport correspond to a server that is a loose router. > > It totally forbids this forwarding-to-strict-router, ONLY loose router > is allowed. > > Why there's such a difference? Ok - I take what I sent to Iñaki back - I see the inconsistency and will log it for clarification. (Which I suspect will come in the form of removing strict routers from the spec) To directly answer the why - we knew the strict routing behavior was really broken when we were working on 3261 - the creation of loose-routing was one of the big bug-fixes that went into that spec. However, _at the time_ there were still several strict routers deployed and we worked to leave in some backwards compatibility. Allowing a blind forward to a strict router when no Route header was present was asked for fairly late in the editing process (if I remember correctly) and we missed that place to touch when editing it in. So, if this inconsistency is causing you pain in a real deployment situation (as opposed to this being something you just noticed as an inconsistency), I'd like to know. (And I strongly encourage you to do whatever it takes to change any proxies you have that are still strict routing.) RjS > > > thanks > > Regards, > -Rockson > _______________________________________________ > 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
