inline.

Victor Paulsamy wrote:
> 
> Comments inline:
> 
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Murali
> > Medikonda
> > Sent: Wednesday, May 22, 2002 12:01 PM
> > To: [EMAIL PROTECTED]
> > Cc: Don McKinney
> > Subject: [Sip-implementors] OFFER/ANSWER after Hold
> >
> >
> > All,
> >
> >     consider the following scenario:
> >
> >     Client A and Client B are in a stable call (SDP is offered in the
> > INVITE and
> >                                                                    is
> > ANSWERed in the 200OK)
> >
> >
> >      Client A holds Client B by sending a re-INVITE (IP address set to
> > 0.0.0.0)
> >                            (I realize this method of holding a session
> > is no longer recommended)
> >
> >      Now, when Client A reverts back to B, what should client B's
> > behaviour be when
> >
> >      (a) Client A sends a re-INVITE with SDP - offer SDP (new or same
> as
> > earlier) and expect an
> >                      answer in the 200OK)
> >
> 
> If A offers the same SDP, B will answer with the very same SDP. If some
> of
> the existing session characteristics have been modified and/or new media
> has
> been added, B will respond accordingly. If new media is to be added, it
> has
> to be added to the already negotiated SDP, though.
> 
> >      (b) Client A sends an re-INVITE - with NO SDP - i.e wait for the
> > offer in 200OK and send an
> >                      answer in the ACK.
> >
> 
> See the post to the previous question on the list. The UAS would respond
> with Global Error (6xx).

No, this is not correct.

It is valid to send a re-INVITE without SDP. In that case, the offer can
come in the 2xx (but is supposed to be something that is likely to be
acceptable), and then the answer in the ACK.

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.            72 Eagle Rock Avenue
Chief Scientist                         First Floor
dynamicsoft                             East Hanover, NJ 07936
[EMAIL PROTECTED]                 FAX: (973) 952-5050
http://www.jdrosen.net                  PH:  (973) 952-5000
http://www.dynamicsoft.com
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