DIN EN 300188-4:2000-01

Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol; Three-Party (3PTY) supplementary service - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (Endorsement of the English version EN 300188-4 V 1.4.1 (2002-04) as German Standard).

Integrated Services Digital Network (ISDN) - Three-Party (3PTY) supplementary service; digital Subscriber Signalling System No. one (DSS1) protocol - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (Endorsement of the English version EN 300188-4 V 1.3.3 (2000-05) as German standard)

Integrated Services Digital Network (ISDN) - Three-Party (3PTY) supplementary service - Digital Subscriber Signalling System No. one (DSS1) protocol - Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user (Endorsement of the English version EN 300188-4 V 1.2.4 (1998-06) as German standard)