Subject: [Ecrit] draft-winterbottom-ecrit-location-scope-req-00 review

From: "James M. Polk" <[email-masked]>
Date: Tue, 08 Mar 2005 23:33:41 -0600

James

I have a few comments regarding your ID:

In the abstract:

"An example of such a service is the emergency services network, where the 
location of a caller is known with in the domain of the telephone network, 
while the name or true identity of the caller is not intrinsically known."

In not sure I understand the relevance of "...within the domain of the 
telephone network..." as we're talking about VoIP in which there cannot be 
an assumed provider, therefore no assumed domain (much less telephone based).

Additionally, what's the significance of you statement that the location of 
the phone is known but the user isn't? That's true in the PSTN today, so it 
isn't special here.

In the Introduction:

"In the interests of continuous improvement, it is desirable that 
incidences of erroneous location information being provided can be traced 
back to an answerable access provider and corrected. "

This seems to be the main thrust of your introduction, and I do not believe 
it is chartered by ECRIT to be addressed, however valuable this is.

in section 2 "Terminology", you define domain as a service. At my home, I 
have a telephone service from SBC over my landline. I have VoIP access 
through Comcast (by BB over HFC Cable provider) and SBC (via DSL) - both of 
which I connect to Cisco's internal network over a VPN for telephony 
connectivity inside Cisco's corporate network. I have cellular service 
through AT&T Wireless (which is merging with SBC). My wife has cellular 
service from Verizon.

All this is at the same legal and postal address. Is this the same 
jurisdiction as you define a domain? If this is not clear to everyone, 
perhaps there is a need to modify the definition of domain to an 
"administrative domain", generally meaning within a specific provider or 
federation of providers.

"Domain Authentication and Validation Entity" doesn't need to be defined 
because it is not within the scope of the ECRIT WG or the IETF.

This WG will route a message based on the location provided. The message 
doesn't have the ability to reliably indicate a location is "validated" - 
without a global PKI and a global Certificate Authority for all PSAPs and 
ECCs with the root key installed in every multimedia device that could 
communicate with a PSAP or ECC.

3.1 "A certain level of authentication and validation
    around the source of the location is required for the domain in which
    the information is to be used."

I don't believe this is within the charter of ECRIT, and therefore should 
be removed from work being considered in this WG.

3.2"...the location used for routing and which is reported
    to the emergency services operator, must be the actual location of
    the caller at the time of making the call."

I don't know how it is possible for the system to convey the "right" 
location the caller, although this is the goal always, because in IP, there 
cannot be a physical location dependency of the end-system ubiquitously.

3.3 "...   The location information MUST be attributed to a specific End-User."

If I use your cellphone to call 911, will I be in violation of this 
requirement (aside from the fact that your cellphone isn't IP based yet)? 
If I can make such a call in the future, this requirement is unachievable, 
and should be modified or removed.

3.4 "it must be possible for an End-User to discover and utilize an
    answerable source of location in the access network they are using."

how can this be accomplished without the user entering a trusted token the 
PSAP/ECC will identify itself with during a 911 call?

This breaks for mobility and nomadic endsystems, which IP devices must all 
be considered here (because they can be moved and still access the same 
services).

Requirements 5, 6 all seem to invalidate the use of DHCP and GPS and manual 
entry.

Requirements 6, 7 - "certified location" - does that mean integrity 
protected, cryptographically signed location?

Req 8 (end-users may not be able to get location) seems to contradict Req 5 
(end-users must be able to get location)

cheers,
James

                                *******************
                 Truth is not to be argued... it is to be presented

_______________________________________________
Ecrit mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/ecrit