Subject: RE: [Simple] Tuple references and device coupling

From: "Rosen, Brian" <[email-masked]>
Date: Thu, 3 Apr 2003 11:06:57 -0500

> A tuple represents a service (communcation medium), the 
> contact address represents the device where that service is 
> running. How does that sound? If I choose not to include a 
> contact, then I'm just publishing that I'm available for that service.
It wouldn't work as a definition for me, although I'm not sure
that it makes a practical difference.  The contact address in
my view represents multiple devices; the called party forwards
to the appropriate device based on calling party, presence state
and a ruleset the called party establishes.  I'll only give
you one contact address for a specific service (you'll actually
find I only have one contact address for multiple services,
but I don't think that matters.

Also, please tell me if the "audio" service is different from
the "video" service?  As a practical matter, we have IM, we have
email, and we have "realtime multimedia", which is some combination
of audio and video available at a single contact URI with a sip: 
scheme.

> 
> A copositor will have to combine tuples representing the same 
> service (medium) that don't have contact addresses and 
> possibly remove them completely if there is a tuple with a contact.
Jonathan doesn't want to do that; he wants the compositor to
give you all the tuples representing the same service on multiple
devices.  I would do that; give you one tuple with one contact.

Brian
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From: Jonathan Rosenberg <[email-masked]>
Date: Mon, 07 Apr 2003 10:47:35 -0400

> devices.  I would do that; give you one tuple with one contact.

Please do not put words into my mouth.

That is NOT what I am saying. I am saying that there are multiple, 
useful ways to report presence. The variation we are discussing here is 
where the power of decision lies - does it lie with the caller, or 
callee. In the former case, the presence system reports fine grained 
information, such as specific devices and the services available on 
them. In the latter case, the system hides specific contact information, 
and only reports "service level" availability information - whether I am 
"available for IM and email". The choice of device lies with the called 
party. There are, of course, shades of grey inbetween.

I believe that both cases, and all the variations in between, are 
useful. I furthermore believe that it is the presentity (along with 
their service provider) that ultimately decides which model is important 
for them. It may very well depend on who's asking. I would guess that in 
cases where it is an application which is subscribing, fine grained 
information may be more useful.

So, I am seeking to ensure that presence systems can support all of 
these cases, rather than just the case you are interested in, Brian.

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.                600 Lanidex Plaza
Chief Scientist                             Parsippany, NJ 07054-2711
dynamicsoft
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