OENORM EN 301484-4 V 1.1.1
Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Line Hunting (LH) supplementary service - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (incl. Diskette!!!)