I am using CME 4.1 with ISDN PRI. I have got two DID ranges which is mapped to my Ephone's.
dialplan-pattern 1 677011.. extension-length 3
dialplan-pattern 2 677013.. extension-length 3
When user from extension 1.. calls outside then no problem at all.Caller id displays their DID number exactly as 67701174(Eg: if the call made from 174 extension).
When user from Extension 330 - 339 dials out, then the caller id displays as the mainnumber. The reason for displaying main number is if the calling number is different from the DID range allotted then Telco switch will send the main ISDN number.
I tried debugging isdn q931 and found only calls going out from extension 330-339 show as 677067701334(Eg: If i call from extension 334). You can see there is additional digit of 6770 in front of the DID number.
There is no destination pattern clash with any dial-peer also.
Please find attached debug ccapi inout for your reference.