[asterisk-users] Stepped deployment - T1 PRI passthru

[Erik Anderson]

Following the successful deployment of asterisk servers at several of
our branch offices, in the near future, I'll likely be implmenting an
asterisk server at our HQ.  We currently have a T1 PRI terminated on a
legacy PBX.  I'll be doing a stepped deployment in which, via a dual
T1 linecard, the asterisk server will initially pass all
incoming/outgoing calls directly through to the PBX.  As the
deployment progresses, I'll grab individual DIDs and start routing
them to IP phones instead of passing them through to the old PBX.

I'd imagine that this is a fairly common deployment scenario, but
after searching through the wiki, was unable to find any dialplan
"best practices" for implementation.

Would anyone be able to point me in the right direction on this?  I'd
imagine the initial dialplan config to be something like this:

Zap/g1 = T1 to telco
Zap/g2 = T1 to PBX

[default]
exten => _<pattern_matching_our_DIDs>,1,Dial(Zap/g2/${EXTEN})  ;
routes incoming calls to old PBX
exten => _<pattern_matching_external_numbers>,1,Dial(Zap/g1/${EXTEN})
; routes outgoing calls to telco

That's probably way over-simplified, and I'm sure the final
implementation would involve a few different contexts for orginization
and future flexibilty, as well as perhaps needing some code to set CID
information correctly (I'm not sure if that's passed through
automatically).

Am I heading down the right path?

Thanks!
-erik

-- 
Erik Anderson
http://andersonfam.org