Thanks Paul. I want to use MESSAGE an in interim solution for my proof of concept application. The final goal is MSRP. The reason why I want to use MESSAGE on an INVITE session is to avoid proxy side routing processing for every MESSAGE request. Also, there will be no inter-operation issues as the end points shall be same which are part of this POC.
On Nov 14, 2007 9:36 PM, Paul Kyzivat <[EMAIL PROTECTED]> wrote: > > > Vikram Chhibber wrote: > > Hi, > > > > I want to perform page-mode instant messaging (using SIP MESSAGE) on a > > dialog created by INVITE. This INVITE I want for establishing a dialog > > on which I can send SIP MESSAGE only and there will be no media. I do > > not want msrp either. > > The first question is *why* you want to do this, and whether you should. > If you establish a *session* for sending page-mode messages, then you > are really doing session-mode messaging. Long ago the need for session > mode messaging was identified, and this approach was considered. It was > then abandoned in favor of the MSRP approach. > > So, if you are trying to create a mechanism for doing session mode IM > you are encouraged to *not* do this, and instead use MSRP. > > IIUC, Microsoft does use MESSAGE within an INVITE dialog usage. I think > they did it before MSRP was adopted. I suppose if your goal is to > interoperate with them then you ought to do whatever they expect. > > > In this case, how should I construct offer and then answer SDP? > > SDP with no m line should be fine but is there some media description > > defined for this purpose? > > Mechanically you can create an SDP offer that has the required lines but > doesn't have any m-lines. It constitutes a legal offer, and if you can > get somebody to accept it then you are on your way. > > The problem of course is that an offer with no media is odd - there is > no real hint what the point of it is, so a UAS is likely to reject it. > What you want is some way to indicate the purpose of the session and how > you intend to communicate. > > AFAIK there is no *standard* way to do it. I think MS uses some special > m-line for the purpose. But I have no details. > > Paul > > > Thanks, > > ~Vikram > > _______________________________________________ > > 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
