Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) and Signalling System No. 7 (SS7) protocols; Call Forwarding on Not Reachable (CFNRc) supplementary service for Cordless Terminal Mobility (CTM) phase 1 - Part 6: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the network (Endorsement of the English version EN 302094-6 V 1.1.1 (2002-02) as German Standard)