Subject: RE: [Ecrit] Issue 15 (civic location validation)

From: "Roger Marshall" <[email-masked]>
Date: Wed, 19 Oct 2005 16:25:45 -0700

A couple of questions around validation to revisit (from 9/14).  This
needs an answer, one way or the other - in light of needing to publish
the next ECRIT requirements draft version.

The item below is listed as critical within the ECRIT issue-tracker,
(issue 15) 
at: http://www.ietf-ecrit.org:8080/ecrit-req/

L6.  Validation of civic location: It MUST be possible to validate an
address 
prior to its use in an actual emergency call.

# is this a protocol requirement or an architecture requirement? 
# when should this validation take place? 

Please comment on the above two questions.

Thanks.

Roger Marshall.

>-----Original Message-----
>From: [email-masked] [mailto:[email-masked]] 
>On Behalf Of Brian Rosen
>Sent: Wednesday, May 18, 2005 6:47 AM
>To: [email-masked]
>Subject: [Ecrit] Text for I7
>
>I7.  Traceable resolution: The entity requesting mapping 
>SHOULD be able to definitively and securely determine the 
>entity or entities who provided the emergency address 
>resolution information.
>
>
>
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---

From: Henning Schulzrinne <[email-masked]>
Date: Wed, 19 Oct 2005 21:26:00 -0400

I had raised a related issue in a slightly-tangential way a few days back.

I think there are two somewhat separate issues:

- if validation means "is a mapping request during an actual emergency 
going to return a URL or an error code", then I don't see how this 
requires anything at all since the mapping system can't know whether 
it's being called in test or in a real emergency (and it shouldn't matter).

- if validation means "provide an error indication and maybe hints as to 
how to fix the problem", there might be a difference between test and 
"real" operation. In "real" mode, the mapping protocol might provide a 
URL even if the street name can't be found if the whole town has the 
same PSAP. In "validation" mode, it would presumably tell the client to 
go fix the problem. It is not clear to me, however, that this *requires* 
two modes. One could simply return a warning indicator that part of the 
location didn't match. As I mentioned, depending on the underlying 
database, validation could mean anything from "your cubicle number 
exists" to "I don't know anything about streets, but I recognize your city".

Thus, this requires more details on what we want from validation. Given 
that the depth of validation depends as much on the data available as on 
the protocol, maybe the requirement is that the protocol can perform a 
partial match on civic locations and, importantly, indicate when it 
either did not match ("no clue") or failed to match ("known not to 
exist") part of the location information.

Henning

---

From: "Brian Rosen" <[email-masked]>
Date: Wed, 19 Oct 2005 21:56:26 -0400

This is a protocol requirement - the protocol must have a way that can be
used to determine IF a mapping was needed, could one be provided, which is
the same as answering the question we really care about, which would be is
the location a location we know about and can dispatch responders to. 

The validation takes place any time before the call.  The practical answer
is that it takes place when an address is loaded into the Location Server
(LIS).  In the scheme of things, this means when you create the actual
address associated with, say, a wire pair, you validate it before you put
that address in the database.  Then any subsequent use is okay.  You have to
be able to periodically revalidate, because the database undergoes slow
change.

NENA would like validation to be able to return things that mapping would
not normally return.  For example, it would be desirable if when you did a
validation query, and the location did NOT validate, that you got one or
more suggested alternatives for the supplied location which would be valid:
I don't have a Main St, I have an East Main Street or a West Main Street or
Main Ave.  When you do the mapping, a failure gets you a "default route".

Brian

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On Behalf Of
Roger Marshall
Sent: Wednesday, October 19, 2005 7:26 PM
To: [email-masked]
Subject: RE: [Ecrit] Issue 15 (civic location validation)

Thanks.

Roger Marshall.