Subject: RE: [Simple] MESSAGE sessions - over TCP

From: [email-masked]
Date: Mon, 1 Oct 2001 13:26:39 +0200

I think message chats should be wrapped by an INVITE/BYE, as a chat 
session is indeed a session.
However, unlike other media types, a chat starts with a single message, 
and it seems to me a burden (for the SIP network) to require that a single 
message be sent using an INVITE wrapper.
The actual session will be initiated by the callee of this initial message 
(so he can send the reply within the session)The only protocol change 
required is a way to associate the original message (which was sent before 
the SIP session was created) with that session.

Jonathan Rosenberg <[email-masked]>
26/09/2001 22:30

        To:     "'Petri K. Koskelainen'" <[email-masked]>, [email-masked]
        cc:     [email-masked]
        Subject:        RE: [Simple] MESSAGE sessions - over TCP

> -----Original Message-----
> From: Petri K. Koskelainen [mailto:[email-masked]]
> Sent: Wednesday, September 26, 2001 1:21 PM
> To: [email-masked]
> Cc: [email-masked]
> Subject: Re: [Simple] MESSAGE sessions - over TCP
>
> Is there a consensus that INVITE-established IM messaging
> session idea is ok ? (in addition to one shot MESSAGEs)
>
>
> If we can agree on that, then we can continue with other
> problems, like:
> - messaging protocol/format inside a session (e.g. SIP
> MESSAGE over TCP)
> - direct end-to-end vs. via signaling proxies vs. via IM servers
> - compression (hopefully this does not have to be discussed here)
>
> There should be a resolution on this asap.

Yes, part of the reason we are circling around is that we have not been 
able
to break the problem into pieces. Clearly the first is the question Petri
has asked - can we agree that a session model for messaging (session model
being to wrap it in INVITE/BYE, and the messages are viewed as a media
stream.) THis says nothing about how they are transported, and wouldn't 
rule
out sending them over the signaling channel.

I strongly support this need for a session model. I think most have
expressed support for it, with a few notable exceptions (Dean, I think).

I think its time for the chairs to make a ruling on consensus on whether 
to
pursue a session model as defined above.

We would still retain the paging model of course,

-Jonathan R.

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

---

From: Paul Kyzivat <[email-masked]>
Date: Mon, 01 Oct 2001 09:17:12 -0400

[email-masked] wrote:
> However, unlike other media types, a chat starts with a single
                                            ^^^^^^
                                            may start

> message, and it seems to me a burden (for the SIP network) to require
> that a single message be sent using an INVITE wrapper.
> The actual session will be initiated by the callee of this initial
> message (so he can send the reply within the session)The only protocol
> change required is a way to associate the original message (which was
> sent before the SIP session was created) with that session.

What you suggest is one usage model, where the sender of the first
message doesn't anticipate a conversation, but the recipient decides a
session is required. But it certainly isn't the only usage model - it
quite possible that the need for a session is anticipated from the
beginning.

Certainly both of these scenarios can be supported. Yours is simply a
combination of paging mode usage plus session mode usage. It does get a
bit complicated if you wish to tie the session to the initial page, but
I don't know if that is really required.

	Paul Kyzivat
	Cisco Systems