Subject: Re: [Simple] IM over the signaling connection

From: [email-masked]
Date: Thu, 4 Oct 2001 22:18:35 +0200

We have got the following wording:

<<<
The IESG has some concerns that this mechanism constitutes the use of SIP
as a transport protocol. In other words, once the session has been
established
between the two endpoints by the INVITE, if the MESSAGEs can only go
directly end-to-end, then their headers and related protocol apparatus are
entirely superfluous and may do more harm than good. We saw during the
meeting last week that there were definitely some pitfalls to allowing
methods other than MESSAGE across the IM stream (as well as questions about
overlapping transactions, redirection, forking, and so forth), and it isn't
clear that the overhead is justified if MESSAGE is just an envelope for its
encapsulated MIME payload. The IESG was particularly concerned, in addition
to the protocol overhead, with congestion characteristics of the messaging
session and with the precedent that could be set by using SIP in this
fashion.

I am not sure if the IESG objects to the use of SIP as transport due to:
1. The signalling connection is for signalling only and not for any media.
2. The overhead it will cause to the protocol.
3. The superfluos headers.

If it is 1, then why a single MESSAGE is allowed? if it 2 or 3, then we can
limit the usage when the
session is held over the signaling connection.

avshalom
Sametime/Lotus/IBM

                    Ben Campbell                                                                                       
                    <bcampbell@dynami        To:     [email-masked]                                               
                    csoft.com>               cc:     [email-masked]                                    
                                             Subject:     Re: [Simple] IM over the signaling connection                
                    04/10/2001 17:28                                                                                   

It is not so much that it is being ignored as that the IESG has told us
they will not approve it.

[email-masked] wrote:

> It seems that the possibility of sending MESSAGEs of sessions over the
> signaling connection is being ignored.
> I am not sure that there is a consensus not to use it.
>
> It think that we can agree on sending MESSAGEs of sessions on the control
> connection. We should keep the
> header of the MESSAGEs to a necessary minimum and agree on a maximum
length
> of MESSAGEs to be sent
> on the signaling connection. Given this, the impact on the control
> connection will not be different from a one time
> MESSAGE and NOTIFYs.
>
> avshalom
> Sametime/Lotus/IBM
>
>
> _______________________________________________
> simple mailing list
> [email-masked]
> http://mailman.dynamicsoft.com/mailman/listinfo/simple
>

---

From: Ben Campbell <[email-masked]>
Date: Fri, 05 Oct 2001 08:55:33 -0500

> session is held over the signaling connection.

The wording mentions 1 and 3 specifically. As far as why we allow 
page-model MESSAGE, there is some belief that chat sessions will 
typically involve more traffic (lots of short messages) than individual 
page-model messaging will.

I do not understand what you mean by limiting the usage.