[asterisk-users] ISDN

[Joe Greco]

> I'm in the process of setting up Asterisk in a SOHO environment using =
> ISDN for trunking.  More specifically a BRI 2B+D circuit where one SPID =
> is used for the business and the other is used for personal.  The =
> circuit already exists, but is presently being interfaced to POTS phones =
> via a TA.
> 
> This configuration is not very common in the US, but we are fortunate =
> that our LEC offers it price competitively with equivalent POTS services =
> and it makes more sense, both in terms of voice quality (4 wire digital =
> to the PABX) and flexibility.
> 
> Ideally it would allow any combination of two calls, identified by SPID.
> 
> If anyone has done anything similar, or has any experience with BRI =
> ISDN, I would appreciate input and direction.
> 
> If anyone knows where documentation exists on configuring ISDN, that =
> information would also be greatly appreciated.  Asterisk has a bit of a =
> learning curve, and ISDN BRI isn't the most widely used or covered =
> aspect of it.  BTW, I have a strong telecom background, so the theory =
> part of it will not be a problem, only the necessary documentation to =
> apply it to Asterisk.

The one solution I've heard, on and off again, that works with Asterisk
here in the US is the Eicon Diva cards.

There are other solutions.  Where I am, we're unreasonably close to a 
local radio conglomerate that has a number of high power antennas.  We
found early on that RF interference was a killer, which caused me to run
a lot of our telecom and data wiring in conduit.

Unfortunately, we discovered that POTS lines were a hell of a mess when
connected to anything more complex than a phone or two.  Lots of RF
interference.  Church radio music on Sundays, even.  So, we brought our
lines in on BRI, which we've used for data and voice elsewhere.

Being eternally frustrated with the lack of ISDN support after maybe 2000
here in the US (we have a bunch of interesting ISDN gear from the 90's!),
I set out to see what I could do to interface BRI to Asterisk.  I *didn't*
go the Eicon route, because at the time it was considered relatively
unreliable.

Instead, we picked up an Adtran Atlas 550, which can handle ISDN BRI, PRI,
POTS, etc.  We have been using the Atlas as a translator to convert BRI
to T1, which works moderately well, but we've seen some issues, mostly in
the capabilities of the Adtran (such as an inability to select the desired
SPID/DN for outgoing calls).

The Adtran has some other amazing capabilities, such as providing FXO/FXS
ports, and even ISDN BRI ports for other devices we'd liked hooked into
our PBX.

Despite that, I'd love to see an ISDN BRI solution for the US.  I might
be willing to test the Eicon Diva Server card...  hm.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.