asterisk users - Jan 2007 - Asterisk Legacy PBX integration and fail-over question,

Hi All,

I have a (legacy) Praxton PBX, it has a PRI T1 input card and 64  
analog extensions through 4 amphenol connectors.

We receive 12 voice channels (other 12 are idle) and have 100 DIDs.  
No caller ID thru PRI though.

The Praxton box is amazing in terms of configuration and flexibility  
but has no VoIP support and the company went poof and it is no longer  
supported, nor spare parts are available, and it's giving me a hiccup  
at least once a week.

I already have good experience with Asterisk installs using TDM  
cards, but never used TE T1s before.

Saying that, I am researching for a full replacement,
(most options are adding up to $13k+)
so, why not also considering a cheaper fail-over solution
that only implies purchasing one TDM and one TE2

Is this scenario possible?

1./ T1 line from the telco with signaling changed to receive caller  
IDs (telco tells me ok)

2./ Telco T1 enters Asterisk Box through a dual TE2 card

3./ Box forwards calls to the legacy PBX trough second port on dual  
TE2 with companion Caller ID info (obviously connected to the legacy  
PBX)

	if the legacy box is down,
	then the calls get routed trough a TDM4 to an analog phone,
	or even better, the * Box runs some test on the T1 to the legacy box  
and rings all four phones on the TDM4 when the legacy box is down,

	and of course the Asterisk box can provide me all the connectivity  
and flexibility Asterisk is capable off,
	with still 12 free channels in all T1 ports


Thank you very much in advance for the enlightenment you'll bring

Andres