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Re: Mobile Multimedia Messaging Service

From: Patrik Fältström <paf@cisco.com>
Date: Sat, 16 Sep 2000 15:41:16 +0200
Message-Id: <p05001954b5e92793f9d6@[193.0.4.72]>
To: vint cerf <vcerf@MCI.NET>, "James P. Salsman" <bovik@best.com>, Jim.Mathis@Motorola.com, ned.freed@innosoft.com
Cc: discuss@apps.ietf.org, ietf-mmms@imc.org, ietf@ietf.org
At 08.12 -0400 00-09-16, vint cerf wrote:
>would it be useful, in the context of establishing peer-to-peer communications
>(or even client/server communications) with limited-function mobile devices,
>to use SIP as a framework for negotiating the parameters that should guide the
>nature of the exchange?

Maybe. The rescap wg is looking into "capabilies" in a different way 
(I presume).

>I'm thinking, for instance, of a web server that may
>usefully discover the functional limits of a mobile before it starts to send
>content to that device. The mobile uses SIP to report to the server that it
>has X amount of memory, Y amount of display area, color or not, average
>data rate it can send or receive, and so on. This information would be used
>by the server to configure what it sends to be compatible with the receiving
>unit.
>
>perhaps this is an idea that is already being pursued in an IETF 
>working group?

I think "discovery" of capabilities is an interesting discussion, and 
of course it should be dealt with aswell. Some of this information 
can be handled by just looking att the tcp control block :-)

Now, I would like, to be honest, this wg to more look at what 
stupid(?) design flaws have been made in the existing protocols given 
certain capabilities than the actual discovery process. IMAP in 
disconnected mode is a good idea, maybe, but might be too chatty. 
I.e. long rtt makes chatty protocols like IMAP and SMTP (just as some 
examples) quite boring. Can something be done about that (batch 
smtp?).

Say we have a very fat pipe between earth and the moon (which current 
tcp should be able to handle). Should we run IMAP over that link 
which have quite some RTT?

What happens if we have only a 2.4k inmarsat sattelite phone with 
900ms rtt, can we still do useful stuff with normal applications 
given ppp (the solution is not to change ppp in this discussion)?

   paf
Received on Saturday, 16 September 2000 09:45:42 GMT

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