Re: [sipcore] composition or just indirection

["Thomson, Martin" <[e-mail]>]

> From: Paul Kyzivat [mailto:[e-mail]]:
> Thomson, Martin wrote:
> > The Geolocation header identifies a PIDF document by value or
> > reference.  A Geolocation header indicates that a) this particular
> > PIDF
> > document contains location information and b) that this location
> > information in particular may be relevant to the processing of the
> > SIP request.
> 
> IMO this is *too* vague.
> 
> For instance, I might want request that a call be routed *to* the phone
> closest to some geolocation. That location is also relevant to the
> processing of the request, but in an entirely different way.

Damn.  You would have to point out my big blind spot.  I've been concentrating on the routing-based-on-caller-location use case too long.

If we also consider that the location needs to be attributed to a particular entity, you can either add syntax that attempts to identify the entity that you are talking about (a "from" or "to" parameter might do this), or you can make the entity constant.  In the interest of simplicity, the latter seems more fashionable:

"
The Geolocation header identifies a source of location information.  This might be a PIDF-LO document that is identified by value or reference, or a geo: URI that includes location information directly.

A Geolocation header indicates that a) that this location information is somehow applicable to the entity that initiated the request and b) that this location information might be relevant to the processing of the SIP request.
"

This is almost the "bold" interpretation that says that this Target’s location should be considered the source of the request.  It does not imply that the Target and source are the same identity.  Nor does it expressly state that the source is actually located anywhere in particular, though we're walking a fairly fine line there.

--Martin