OENORM EN 300369-4 V 1.3.1
Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Explicit Call Transfer (ECT) supplementary service - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (incl. Diskette!!!)