[asterisk-users] Digium TE205P and channelbank

[Eric "ManxPower" Wieling]

phil.dawson at marnock.com wrote:
> Trying to find my feet here.  If I wanted to connect Asterisk to a PRI and
> throw in a T1 Adtran channel bank into the mix for fax machines would the
> following work?
> 
> Connect PRI line from telco to Port 1 on the Digium Wildcard TE205P.
> Connect Adtran TA-624-T1 to Post 2 on the Digium Wildcard TE205P
> 
> also, would I need a crossover to the channelbank or is it a patch lead
> like the connection to the PRI
> 
> 
> any hints / tips greatfully received

Many people have no problems faxing, but that has not been my experience.

Some telcos will let you mix B-Channels on your PRI with standard CAS 
channels.  If you had a voice T-1 (non-PRI) they would be CAS channels. 
The telco some of my clients use, XFone/Louisiana, allows this.

In USA/Canada a PRI is just a T-1 (24 channels) with each channel 
specially configured.  There is no *technical* reason your carrier can't 
make channels 1-12 B-Channels, channel 24 as your D-Channel and channels 
13-14 as CAS/FXO channels.

One thing you might consider is this:

PRI <-> Channel Bank <-> TE110P/Asterisk

I don't know if the Adtran 624 has a 2nd T-1 port on it, but at least 
the 850s do, and maybe the 750s.  You will want to check this.

You could have the channel bank pass thru all your B-Channels and your 
D-Channel out the 2nd T-1 port to Asterisk and to connect the CAS 
channel(s) for faxing out the analog FXS ports on the channel bank.

This also means that even if Asterisk is down you have 1 or more 
standard analog channels coming off the channel bank for faxing and 
emergency phones.  It also means that you can buy a 1-port Digium (or 
compatible) card instead of a 2-port card.  XFone does not charge any 
more for a CAS/FXO channel.  The only disadvantages to this are you 
cannot have your fax number route into Asterisk to be accepted by RXFax 
and then e-mailed to someone.  I just don't like this idea for the main 
fax number.  You can set up combined voice/fax numbers pretty easily and 
people can accept faxes on their DID and get the fax in E-mail.  If this 
failes then the sender can just send it to the main fax number for the 
company.   The other disadvantage is that the fax lines are dedicated to 
faxing and cannot be shared with voice calls into Asterisk.