[Asterisk-Users] PRI in and out

[Rod Bacon]

I am wanting to front-end a legacy PBX with an asterisk box. I have done plenty 
of asterisk work over the last 6 months to PRI circuits, but not with a PBX 
being involved.

I know I can use asterisk and digium cards in this manner, but do I need 
separate cards for the PRI -> Asterisk side to the Asterisk -> PBX side, or will 
a 4-port PRI card do the job? (I already have a spare one of these).

In other words, can I use SPAN 1 as a timing source, then provide timing to the 
PBX connected to SPAN 2 of the same card?

Any advice, or sample configs, would be greatly appreciated.