[LINK] Q re VoIP phones, RF phones and ADSL

[Adrian Chadd]

On Fri, Jun 15, 2007, Richard Chirgwin wrote:

> There's another aspect to VoIP services which I have observed but not 
> studied in-depth. The VoIP provider has to provision sufficient 
> VoIP-PSTN connections to handle its call load. I've tested five 
> providers at the office, and we have encountered this kind of congestion 
> from most of them (in the Asterisk logs we see entries from the VoIP 
> provider indicating that it has no circuits available to complete the 
> call ... if you have the patience to wade through the log! What I would 
> do for a nice Asterisk Log Analyser...).

A well setup telephony service reserves a number of "trunk" (for various
values thereof) resources for emergency calls. This could be a certain
number of available lines for emergencies which aren't used by normal
calls, but all the modern VoIP documentation point out you should treat
"000" calls as "special" and be prepared to drop existing calls to service
emergency calls.

You also hope your VoIP provider presents the correct CLID to however
they tie into their upstreams, and you hope they've submitted the correct
location information for their customers so your "000" call correctly
matches your location.

(This holds for large and not-so-large companies who are now trunking their
VoIP calls around their city/state infrastructure back to local PSTN services
to avoid intra-office and STD phone call costs. Which address do the
emergency services see when remote office X calls 000?)

(Lawyers; whats the legality of users testing that their emergency calls
are functioning normally with correct location information? Can you
simply call 000 and state its a test?)



Adrian