[TriLUG] asterisk question
dave at jamsoft.com
Sat Nov 15 22:03:25 EST 2008
As Matt said, Asterisk should do this, no problem. On how *I'd* solve it (acknowledging others may do it differently):
. To restrict the dialing, configure one outbound route with just 911 and the property manager's phone number in the dial pattern. No default route - calls complete only if they match the dial pattern.
. You'll need an FXO interface to the POTS line that can *reliably* return an error to Asterisk if it doesn't hear dial tone. Digium makes such a card, and there are also many inexpensive FXO gateway boxes available. I suggest such a box with one FXS and one FXO port, to give you the option to attach an analog phone to the FXS port for testing and future use. Linksys/Sipura and D-link work well. Grandstream is cheap (nuff said). I've also used an AudioCodes 8-port FXO gateway box - worked fine, a little expensive. Cisco hardware is trustworthy.
. The Asterisk trunks pointed to by the above outbound route could simply be the FXO port (POTS line) first, followed by one or more SIP trunks.
What I can't do is point you to turnkey Linux-based Asterisk boxes that boot from flash. They do exist and the one I played with three years or so ago worked fine.
Last: providing 911 service is a serious matter so test well and regularly. Make sure the caller ID the Asterisk system sends to your SIP termination provider(s) is the same as for the POTS line, and the POTS line has correct 911 information (street address) associated with it. So no one's feathers get ruffled, use a recommended dialog when you do test 911, e.g. http://www.npac.com/cmas/co_docs/911-test-script-Wireless.doc or for the HTML version, http://188.8.131.52/search?q=cache:efpGcPPmkToJ:www.npac.com/cmas/co_docs/911-test-script-Wireless.doc+911+test+script&hl=en&ct=clnk&cd=2&gl=us
----- Original Message -----
From: "Greg Brown" <gwbrown1 at gmail.com>
To: "Triangle Linux Users Group General Discussion" <trilug at trilug.org>
Sent: Saturday, November 15, 2008 6:28:04 PM GMT -05:00 US/Canada Eastern
Subject: [TriLUG] asterisk question
I want to install an Asterisk system for about 10 computers. I'd like to
restrict the phones to dialing either 911 or a property manager. I assume
this is possible. Is it?
There will be a single POTS line in this configuration and that POTS line be
used for the DSL connection. Could I set up some kind of system that would
uset the POTS line first and the upstream VoIP provider second if the POTS
line were already used? What hardware woudl be required for this? Are
there any embeddded systems that could do this?
Why am so I smitten with embedded systems? No fans. No moving parts.
Because the phones will be restricted to only 911 and the property manager
and there will be no incoming calls is it possible to somehow recored all
outgoing calls in case there are any future legal concerns involving these
I'm really scratching my head here. Any thoughts or ideas would be greatly
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