Re: [Sipping] I-D on service identification now available

[Dean Willis <dean.willis at softarmor.com>]

On Fri, 11 May 2007 20:08:29 -0400
Paul Kyzivat <pkyzivat at cisco.com> wrote:

> Certainly it should be fine for the phone to be configured with the 
> server to use.
> 
> Using a URN is a tradeoff between need for configuration and need for 
> standardization. By using a standard URN you can avoid the need for 
> configuration, while delegating the job of allocating a particular 
> resource to a proxy.
> 
> This is not much different from the use of a service:sos URN for 
> emergency calling. In that case we are using standardization to allow 
> delegation of the selection of the PSAP to a proxy.
> 
> It does have some of the same issues as service identification. But at 
> least it is not e2e. It is a contract between you and your provider.

yes, but which provider? Even in a "simple" user->originating provider->terminating provider->user model, there's a question of which "provider" executes on the URN, and what happens if the two providers have conflicting efinition of the URN.

When there is a many-layer model, with possibly remote service invocations, it gets complicated.

The URI model doesn't have this, since it explicitly indicates WHO the service should be provided by.

My guess is that the URN model only works for a few services of global significance, like emergency calling.

--
Dean


_______________________________________________
Sipping mailing list  https://www1.ietf.org/mailman/listinfo/sipping
This list is for NEW development of the application of SIP
Use sip-implementors at cs.columbia.edu for questions on current sip
Use sip at ietf.org for new developments of core SIP