Subject: AW: AW: [Simple] Data model - attempt at summary

From: Boehmer Bernhard ICM Berlin <[email-masked]>
Date: Wed, 3 Nov 2004 08:49:47 +0100

Hi Henning,
service ID: certainly indirection has its drawbacks;
in this case the main question is whether the higher
flexibility of indirection outweighs the overhead
introduced with that. Actually, the whole XML schema
architecture is using it heavily (this becomes obvious
to me each time I edit XML schemas without being connected
to the Internet...:).

deviceID: I agree that, for the IETF, it is more complicated
to solve this issue. For the Open Mobile Alliance, I think,
it is simpler. I issued there a proposal where it is simply
mandated that the device MUST generate a unique ID based on
the UUID URN algorithm. The IETF doesn't have this "comprehensive"
approach to standardization and must rely on the fact that 
the device OSs will provide such unique identifiers.
		Regards Bernhard

> -----Ursprüngliche Nachricht-----
> Von: Henning Schulzrinne [mailto:[email-masked]] 
> Gesendet: Montag, 1. November 2004 22:27
> An: Boehmer Bernhard ICM Berlin
> Cc: Simple WG
> Betreff: Re: AW: [Simple] Data model - attempt at summary
> 
> 
> > - service identification is not yet resolved if haven't missed
> >   something. There seems to be some convergence in the 
> group regarding 
> >   URI as a basis but I think there are some issues here;
> >   see also the draft 
> > 
> http://www.ietf.org/internet-drafts/draft-boehmer-simple-servi
ce-identification-00.txt
>   for a discussion of them. 

This is helpful description, although I have some doubts that adding a 
level of indirection is necessarily the way to resolve the problem. But 
that's a discussion for another day.

> - You once brought up the question of device identification. 
>   Probably I missed here something but I had the impression
>   that it remains an open issue.

I think that having all device components that report device information 
agree on a common, shared identifier is going to be painful and 
error-prone in practice. It seems more likely that they can agree on a 
small set of unique identifiers. Either way, this is largely speculation 
since we don't know yet whether we'll have devices publish their own 
data or whether various pieces of software also publish device 
information, which is then processed, merged, filtered and published.

It would be helpful, if only for my web notes, if somebody could 
summarize as to why they believe that a single identifier is likely to 
work in the multiple-publisher case. One possible compromise is to have 
a primary identifier that has the rule of an element identifier, but 
allow additional matching identifiers that the composer may use to do 
merging.

> 
> Another feature which, however, could be deferred is the question
> of internal service states as presence information (this relies to
> the fifth bullet in your web page). In the abovemetioned draft I
> touched a bit upon that but there is no clear answer on that in the
> moment. 

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---

From: Henning Schulzrinne <[email-masked]>
Date: Wed, 03 Nov 2004 08:21:12 -0500

> to me each time I edit XML schemas without being connected

While it is easy for a mobile provider to publish a UDDI directory entry 
for its limited number of phones, say, it seems much harder for the 
average user in a corporate network or using a provider. They will have 
to rely on the provider or corporate network to host this information. 
Unless you want to rely on web pages for configuration, every new source 
of information means that there needs to be authentication, a means to 
publish this information and to change it.

The only advantage of inclusion by reference is space saving. Otherwise, 
whatever service description you include by reference can also be 
included by value.

The space saving only matters if the mobile transmits the information. 
This seems unlikely, even with inclusion.

Thus, I'm at a loss to see why adding another protocol machinery for 
managing UDDI stores to every PUA or PA adds significant value that 
outweighs the complexity incurred.

Henning

---

From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 10 Nov 2004 01:54:09 -0500

I agree with Henning here; I don't see how the layer of indirection 
solves anything.

-Jonathan R.

-- 
Jonathan D. Rosenberg, Ph.D.                   600 Lanidex Plaza
Director, Service Provider VoIP Architecture   Parsippany, NJ 07054-2711
Cisco Systems
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