Hi, >Why is "Fake Forking" OK to do? What is the issue that the >SDP can only be changed during "Fake Forking" and if this is >acceptable then it seems that changing streams between 18x >and 200 should be OK as well. > >The overhead in handling a "Fake Forking" case seems to be >unnecessary and can affect call performance.
The point is that - within the same dialog - you cannot change the SDP from 18x to 200. Fake forking is away to get around that, by using separate dialogs (To tag values). >Seems like a lot of older devices still allow the change of >the SDP. I think Broadsoft pre rel 14 does it this way. Well, such behavior is not according to the standard. Regards, Christer > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf > Of Christer Holmberg (JO/LMF) > Sent: Thursday, February 15, 2007 7:06 AM > To: Ira Kadin; Sanjay Sinha (sanjsinh); Miljanovic, Nebojsa > (Neb); [email protected] > Subject: Re: [Sip-implementors] SDP in 2xx response after reliable 18x > > > Hi, > > >It can be the situation when the call originally is > connected to some > >media announcement server (connected - meaning getting RTP, > for example > >to play ringback), than - to the final user. In that case > the UAC has > >to switch from the media in 18x SDP to the media in 200 SDP > > It is not allowed, for the same dialog. > > But, in your use-case you can use "fake forking" (see separte > thread), and use different To tags in the 18x and 200. Then > the 18x (tag=x) can be used for the announcement, and 200 > (tag=y) be used for the UAS. > > Regards, > > Christer > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf > Of Sanjay > > Sinha (sanjsinh) > > Sent: Wednesday, February 14, 2007 8:37 PM > > To: Nebojsa Miljanovic; [email protected] > > Subject: Re: [Sip-implementors] SDP in 2xx response after > reliable 18x > > > > > > Option 2 does not seem correct. Option 1 is correct and you > may also > > want to ignore the sdp in 200 OK, just treat it as if there > was no sdp > > in 200 OK. > > > > Sanjay > > > > >-----Original Message----- > > >From: [EMAIL PROTECTED] > > >[mailto:[EMAIL PROTECTED] On Behalf > > Of Nebojsa > > >Miljanovic > > >Sent: Wednesday, February 14, 2007 12:30 PM > > >To: [email protected] > > >Subject: [Sip-implementors] SDP in 2xx response after reliable 18x > > > > > >Trying to get a feel on how various developers interpret RFCs 3261, > > >3262 and 3264. > > > > > >If you are acting as an UAC and you have received SDP in > > reliable 18x > > >response (i.e. PRACK was used), and then again that same SDP > > comes in > > >2xx, what will you do? > > > > > >1. Verify that 18x and 2xx SDPs are the same and accept it. > > > > > >2. Tear down the call since you consider SDP in 2xx as an invalid > > >Offer. > > > > > > > > >Also, do you know of any UAs that require 2xx to contain SDP > > even after > > >Offer/Answer was done with 183/PRACK. > > > > > >Thanks. > > > > > > > > > > > > > > >_______________________________________________ > > >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 > > > > _______________________________________________ > 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
