asterisk users - Oct 2006 - Stripping digits on internal calls

Hi,

I'm trying to interface an SDX/Lucent/Avaya INDeX switch with an 
asterisk box using the INDeX's networking feature.

This works but all calls passed to the index are received with a 5 
digits rather than the 4 they really have. Users on the INDeX dial 4 
digits, the digit 6 is added as a network identifier. The calls are 
being passed via a PRI ZAP trunk running QSIG on a Sangoma A102. I treat 
all calls received in this way as [from-internal]

I'm looking for any examples of handling incoming calls so that I don't 
have to have a ring group for each extension set up.

Being able to just add the extensions on their own would be great - can 
anyone point me in the right direction?

M@t :o)