RE: crypto delay (Notes from Non-meeting)

Agreed! With SIP, location information must be in call setup. Even
Wireless Phase II has issues with this that they have not solved as the
location information lags call setup by several seconds. In a WPII call,
the PSAP choice is made by simply sending the call to the PSAP that services
'most' of the territory covered by the tower the caller is using. The PSAP
will then 'transfer' the caller to another PSAP if appropriate. Not a
choice with SIP as users are not 'tower bound'.

Hmm, maybe we need one PSAP per country............

-Marc Linsner-

-----Original Message-----
From: Henning Schulzrinne [mailto:hgs@cs.columbia.edu]
Sent: Wednesday, April 03, 2002 8:45 AM
To: Rosen, Brian
Cc: 'Andrew Daviel'; 'geopriv@mail.apps.ietf.org'
Subject: Re: crypto delay (Notes from Non-meeting)

I don't think that's a viable option. The location information is used
for two different things:

- selecting the appropriate emergency call center that handles a
particular geographic region (PSAP in the US);

- providing the emergency call center with user location information

Clearly, the first requires location information as part of the call
setup and cannot be deferred until later in the call.

>
> I'll conceed the point that it's possible to have the location information
> come later than the call completion. That is undesirable (because
> it is actually very interesting to route the call in the emergency center
> based on location, something not possible now), but it's concievable.
> It's also not a great way to deal with in in SIP - rather than simply
> shoving the location in the INVITE, we have to create a mid call dialog.
> That is also possible, if undesirable.
>
> Brian
Received on Wed Apr 3 09:17:59 2002