[Sipping-emergency] Re: Emergency-req: remarks 1-4

At 06:21 PM 2/22/2003 -0500, Henning Schulzrinne wrote:
>>Because I've had much writing of my own this past few weeks, and with the 
>>deadline approaching for -00 IDs, I apologize for this coming so late.
>
>Thanks for your extensive comments. Remarks inline where needed. I'll 
>split my response to keep things manageable.
>
>>#3 - "Emergency call center (ECC): An emergency call center (ECC) 
>>receives emergency calls within a specific geographic area..."
>>Comment: London has what you refer to as ECCs, but the have all calls 
>>from the surrounding regional area come into a single center, the Call 
>>taker(s) determines where the call is coming from, then the emergency 
>>personnel are dispatched to the appropriate location from that 
>>centralized ECC. In other words, local emergency personnel are not 
>>called, they are dispatched by the ECC in London.
>>This might be a subtle difference to your intent, but it is fairly 
>>different than the US model where you call (or are patched through to) 
>>the local ECC.
>
>Hmm, isn't that the same as having a large regional PSAP in the US? I 
>think they are called consolidated PSAP.
>
>Thus, I'm not sure how my definition contradicts the London example - the 
>London ECC "receives emergency calls within a specific geographic area and
>dispatches emergency services, such as fire, police and rescue services."

Many are not educated on the details or implementations of 911 and e911. 
Most in fact, believe this is a local issue only (meaning limited to a 
city, or region of a large city). I wasn't really commenting on 
contradictions (sorry if it came across that way) as educating how things 
are now. IP will only expand the territories,

>>#4 - From section 4 "Last Mile" you have omitted Cable access. I mention 
>>this because existing HFC Broadband connectivity can be as much as 100 
>>miles away from the MSO Headend facility. This could easily have an 
>>affect on which ECC (PSAP is appropriate to contact). This is in contrast 
>>to DSL which is typically limited to 22,000 ft from the CO, with most not 
>>possible at distances greater than 15,000 due to the poor cables in the 
>>ground. This limits the jurisdictional boundaries that can be crossed by 
>>this technology.
>
>Actually, last-mile is not visible to the "subscriber", so DSL or whatever 
>are simply the way that the ECC connects to the PSTN selective router. (I 
>suspect US PSAPs would not choose a cable modem as their access 
>technology, but that's a discussion we don't need to have here.) Maybe 
>your remark hints at a broader lack of common understanding what 'last 
>mile' means. I'm referring to the model described in the NENA TID that I 
>sent around yesterday, where IP only replaces the analog or digital trunk 
>from the last switch to the PSAP. In that model, there is no way that a 
>subscriber can directly send a SIP request to the PSAP.

There are several installations that use HFC as primary line. They are 
installed in most of the largest cities in the US. The products are from 
Arris (co-owned by Nortel at one time, I use to work on the Nortel team of 
that partnership several years ago). Dallas/Fort Worth (where I am) has had 
the opportunity to convert over to HFC and off wire-pairs for more than a 
year for my primary phone service. The provider is a little company called 
AT&T. The business goal of AT&T is to penetrate all the 32 NFL cities 
(their term).

At the MSO Headend, there is connectivity to a Class 5 switch (either 
co-located, or feed to it). Thus, this MSO might be quite a ways outside of 
the PSAP jurisdiction (likely not 100 miles in AT&T's case in the near term 
- but we are talking about years from now also)

>You obviously raise a good point that illustrates that even in a near-term 
>deployment of VoIP over a current cable plant causes difficulties for the 
>last-mile model. (In NJ, the bastion of home rule, a PSAP might cover only 
>one square mile, so we get DSL service out of a neighboring community.)
>
>to be continued
>

cheers,
James

               *************************************
"People generally demand more respect for their own rights than
                          they are willing to allow for others"

_______________________________________________
Sipping-emergency mailing list
Sipping-emergency@ietf.org
https://www1.ietf.org/mailman/listinfo/sipping-emergency