[Asterisk-Users] DID trunks -- equipment requirement

[john lawler]

Hi guys,

I posted a somewhat similar question about a month ago and got a 
thoughtful resonse from Steven Critchfield, but I've got a quick follow 
up question to it.

I'm looking to setup a 16 extension / 10-14 phone line Asterisk install 
for a customer who would like to have DID numbers for the extensions, 
since they're currently on Centrex and already have the 1-to-1 
correspondence.  Since I'm in a less populated area of the country, SBC 
doesn't seem to have much in the way of fractional T1 products (on the 
scale that we need them) available, so I think my only option for DID is 
to use (analog) DID trunks for incoming calls and POTS lines for 
outbound calls.

I'm familiar w/ POTS lines and have already done limited testing w/ a 
CAC channel bank equipped with FXO cards and that works fine.  What I'm 
concerned about is the DID trunks.  I've been told they have no dialtone 
and of course you can't place calls on them, but can receive calls.

My question is, in general, should my CAC channel bank w/ the FXO cards 
that work on POTS lines work okay w/ analog DID trunks from the phone 
company?  Might I have to purchase additional equipment to handle the 
DIDs (going into one of two Digium T1 cards I have in the Asterisk 
box)?  Would they be different cards to plug into the CAC channel bank?  
Something totally different?

Sorry to bring what I know is a rather off-topic question here, but the 
SBC guys don't like to help with customer education so much.  As always, 
I appreciate all of your expertise and patience with me and the other 
new guys.

John Lawler