Subject: [Geopriv] Any desire to indicate who inserted location in a message?

From: "James M. Polk" <[email-masked]>
Date: Wed, 08 Nov 2006 14:58:52 -0600

Geopriv

I'm working on the ABNF of the Geolocation header for SIP location 
conveyance, and have discovered a means of indicating which entity 
(currently by type) inserted the location *at*that*URI*, per URI in the 
header  (i.e. this will be a header parameter, not a URI parameter).

For example, if a SIP message includes location-by-value, the Geolocation 
header would have a "cid:" URI that can have a header parameter to indicate 
whether the original phone ( SIP UAC) inserted the by-value location, which 
would be different than if an intermediary server (say a SIP proxy) inserts 
location by-reference.  Here, the Geolocation header would have a reference 
URI, which can indicate that a intermediary (and not the original phone) 
inserted the location.

Here is an example in which there are two locations in a message:

    Geolocation: <cid:[email-masked] ;inserted-by=uac>,
                 <sips:[email-masked] ;inserted-by=proxy>

The above header has 2 locations (one by-value, inserted by the phone) and 
one inserted by a proxy along the signaling path.

An interesting facet of this is the ability to indicate which location the 
message was routed on if a message has multiple locations.  I know this has 
been asked for over the years in both Geopriv and ECRIT. Here is what that 
additional header parameter could look like (notice the "message-routed-on" 
parameter associated with the location-by-reference):

    Geolocation: <cid:[email-masked] ;inserted-by=uac>,
                 <sips:[email-masked] ;inserted-by=proxy
                 ;message-routed-on>

This plays directly to the open issue we have had for some time in the case 
of more than one location within a message, answering "who inserted which 
location?" and "which was used to route the message?".

[ BTW - I'm posting similar messages to this one on the GEOPRIV, ECRIT and 
SIP lists, but not doing one large cross-posting message - as this idea has 
to get multi-list visibility]

Is this a desireable feature/function (indication)?

James

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From: "Richard L. Barnes" <[email-masked]>
Date: Thu, 09 Nov 2006 10:56:22 -0800

James,

It's tempting to offer this information as a discriminator, but I'm not 
sure it really adds any information.  It's easy to imagine cases where a 
location provided by the UAC would be much more reliable than one 
inferred by a proxy, and vice versa. 

--RB

James M. Polk wrote:
> (currently by type) inserted the location *at*that*URI*, per URI in 
> the header  (i.e. this will be a header parameter, not a URI parameter).
>
> For example, if a SIP message includes location-by-value, the 
> Geolocation header would have a "cid:" URI that can have a header 
> parameter to indicate whether the original phone ( SIP UAC) inserted 
> the by-value location, which would be different than if an 
> intermediary server (say a SIP proxy) inserts location by-reference.  
> Here, the Geolocation header would have a reference URI, which can 
> indicate that a intermediary (and not the original phone) inserted the 
> location.
>
> The above header has 2 locations (one by-value, inserted by the phone) 
> and one inserted by a proxy along the signaling path.
>
> An interesting facet of this is the ability to indicate which location 
> the message was routed on if a message has multiple locations.  I know 
> this has been asked for over the years in both Geopriv and ECRIT. Here 
> is what that additional header parameter could look like (notice the 
> "message-routed-on" parameter associated with the location-by-reference):
>
> This plays directly to the open issue we have had for some time in the 
> case of more than one location within a message, answering "who 
> inserted which location?" and "which was used to route the message?".
>
> [ BTW - I'm posting similar messages to this one on the GEOPRIV, ECRIT 
> and SIP lists, but not doing one large cross-posting message - as this 
> idea has to get multi-list visibility]
>

---

From: "James M. Polk" <[email-masked]>
Date: Thu, 09 Nov 2006 15:17:34 -0600

At 10:56 AM 11/9/2006 -0800, Richard L. Barnes wrote:
>location provided by the UAC would be much more reliable than one inferred 
>by a proxy, and vice versa.

exactly, but I think this is a policy choice the protocol doesn't need to 
make - as long as the protocol has this capability to be used

>>header would have a "cid:" URI that can have a header parameter to 
>>indicate whether the original phone ( SIP UAC) inserted the by-value 
>>location, which would be different than if an intermediary server (say a 
>>SIP proxy) inserts location by-reference.
>>this has been asked for over the years in both Geopriv and ECRIT. Here is 
>>what that additional header parameter could look like (notice the 
>>case of more than one location within a message, answering "who inserted 
>>which location?" and "which was used to route the message?".
>>