Re: [sipcore] Draft new version: draft-holmberg-sipcore-proxy-feature

[Paul Kyzivat <[e-mail]>]

inline

On 1/26/2011 8:07 AM, [e-mail] wrote:
> Hi,
> there is an scenario which I would see also within the Internet approach. Perhaps others too.
>
> When you register it would be useful to know if the proper emergency service is served by the provider you are connected to.
> Such an explicit indication would help.
>
>
>     Alice                             P1                     REGISTRAR
>            |                           |                           |
>            |--- REGISTER-------------->|                           |
>            |                           |                           |
>            |                           |--- REGISTER-------------->|
>            |                           |    Path: P1;emergency     |
>            |                           |                           |
>            |                           |                           |
>            |                           |<-- 200 OK ----------------|
>            |                           |    Path: P1;emergency     |
>            |                           |    Service-Route: REG     |
>            |<-- 200 OK ----------------|                           |
>            |    Path: P1;emergency     |                           |
>            |    Service-Route: REG     |                           |
>            |                           |                           |
>
> So that Alice is now sure that an emergency call will get thought and the correct emergency centre will be reached. Which is not even guaranteed in an pure internet environment depended which service provider is chosen.

Why is presence of this parameter on *Path* appropriate? Path has 
nothing to do with new calls originated by Alice. If anything were 
relevant, it would be Service-Route, which Alice would include in Route 
when making a new call.

And, what does the "emergency" capability *mean*? Does it mean that it 
can route requests with urn:sos as the R-URI? Or that it recognizes URIs 
containing dial strings that contain emergency numbers? Or what? (If the 
latter, emergency numbers for what locale(s)?, and encoded in what manner?)

But, why is this needed? Why not just send the request and cope with 
failure to route if/when it happens?

	Thanks,
	Paul