[cisco-voip] Last 4 DID Digits Allowed in CallManager 4.0

[Nasser Khwaja]

Hello,
We presently have a Centrex system and we want the Telco to port our
last 4-digits over to the PRI for our new CallManager
 Many of these extensions last 4-digits start with zero (0) and all
digits (0-9) are used in many extensions as the lead digit. So will we
be able to reuse these extensions?
 Can we also insert a digit in front or have Verizon send a new lead digit?
Thanks
-Nasser.