[asterisk-users] Can I roll my own E911?

[Michael Graves]

On Tue, 22 Apr 2008 11:46:29 -0500, Doug wrote:

>At 09:09 4/22/2008, Michael Graves wrote:
> >On Mon, 21 Apr 2008 23:17:40 -0400, Adam Moffett wrote:
> >
> >>Assuming I only operate in one municipality (I do), and assuming I made
> >>some sort of connection to the emergency services center in this area,
> >>via SIP or a T1 or whatever, does asterisk have a way for me to send the
> >>E911 address data?
> >
> >Others have certainly offered good responses and advice on the matter.
> >But I have a slighlty different approach. I use a GSM gateway to
> >provide what are effectively "cellular trunks" that provide 911 (and
> >411 for that matter) through a cellular carrier.
> >
> >It seems an inexpensive way to ensure 911 service in what is otherwise
> >a 100% VOIP situation.
> >
> >Michael
>
>Hey Michael,
>
>Sounds ingenuous.  Please elaborate.
>
>Do you fake a cellphone, or do you forward through
>a cellphone.
>
>How do you register each phone number? 

There can be several approaches to the mechanics of this. Some more
elegant than others IMHO.

You could use chan_bluetooth to connect an old cell phone. You can get
a "Dock-n-talk" to bridge from the celullar to fixed line world.

I my case I bought a single port SIP-GSM gateway that takes a SIM card
from my cellular provider. I then made the gateway a peer to my
Asterisk. Voila...a GSM trunk. Add dialplan logic to route 411 and 911
calls to that trunk and away you go.

Such gateways are available from 1 to 32 ports. Some are GSM - FXO
while others are GSM - SIP/H.323. Some are even GSM - Skype. Just
Google "GSM gateway" and follow the bread crumbs.

I'm half way through an article on the project that will eventually fin
its way to www.smallnetbuilder.com. I find that I can help offset the
cost of the project by writing it up properly for a publisher.

Michael
--
Michael Graves
mgraves<at>mstvp.com
http://blog.mgraves.org
o713-861-4005
c713-201-1262
sip:mjgraves at pixelpower.onsip.com
skype mjgraves
54245 at fwd.pulver.com