[Asterisk-Users] 911 Q

[Rich Adamson]

> I installed a "Marquee" sign (aka reader board), which was sent emergency 
> information via an RS-232 serial port.  It was pretty nifty, as it was 
> during to 'everywhere must have caller ID' phase in the 90s.
> 
> Most signs are cheap, and can just be placed in the clubhouse window.   You 
> could even have nice little > > > arrows pointing the direction of the 911 
> caller's dwelling...
> 
> Chris Coulthurst
> chris at shuksan.com
> 
> ----- Original Message ----- 
> 
> > OK, got a question on 911.
> >
> > Looking into setting up a couple asterisk servers at a country club,
> > with VOIP phones in each of 100 short-term residential rental units.
> > Approx 100 extensions, approx 24 outside lines.
> >
> > Since everything is geographically at one location, reaching 911
> > correctly shouldn't present a problem.  However, the club wishes to
> > ensure that 911 authorities are able to identify the precise rental unit
> > placing the call.
> >
> > How can we achieve this, short of 'reciting' the unit number aloud at
> > the beginning of the placed call?
> >
> > Thanks for any advice/tips.

Asterisk is more then capable of sending the appropriate callerid info
to any remote site including 911 centers. However, there is a telco between
asterisk and the 911 center that may not have realistic policies/systems
to accept and forward that callerid. So, your objective becomes one of
what the telco will allow you to do (and their support of your objective).

As one example only, the telco might have a switch that does not have
PRI capabilities (I know of many of these), but they provide ANI info
to the 911 centers since that _might_ be the only data they can provide.
If that were the case in your environment, it doesn't make any difference
what you do with asterisk, it won't be supported.

I know from practical experience that a telco's switch (in most cases)
will accept calleridnum via a PRI, but on most central office switches
its an option that needs to be turned on. (Local telco policy _might_
say they will never do that.) Once that option is turned on, you can
send almost anything to them in the form of calleridnum.

The callerid name is a different story.  The central office switch that
_terminates_ any call (including 911 calls) will have a mechanism to do
a database lookup/dip, and if that database has not been populated with
an appropriate callerid name, will not provide callerid names to the
911 center (or anyone else). That essentially says you can program
asterisk to send anything that you want from a callerid name perspective
and it will be ignored in the US. In very general terms, only telco 
personnal have the access to update the callerid database, and usually
that is limited to the CO prefixes they support.

Also keep in mind that not all 911 centers are the same from a technical
perspective. They certainly accept callerid numbers, but they may have
their own local database for names (etc), or, they may also do a database
lookup from some distant database.  If you think about those customers
that subscribe to callerid blocking, cell phones & gps, and the requirements 
of 911 centers, its not hard to visualize several different 911 
implementation approaches.

Talk to a knowledgable telco person (might be somewhat difficult to find
the appropriate person), and talk to the 911 center manager to better
understand what options you might have available. I'd start with the
911 manager as he will know a telco person that understands the
technical requirements.