As long as all your extns have a ddi and the ddi numbers match the extn range, (ie no crazy mapping in LD 49, IDC table), then you can do this in LD 15 in the NET data block. You need to set CLID to yes & then create a entry, say 0 with DIDN set to YES. CLID entry 0 = the 0 after the DN in LD 10/11