EN 300 267-4 : 1.2.4

INTEGRATED SERVICES DIGITAL NETWORK (ISDN); TELEPHONY 7 KHZ, VIDEOTELEPHONY, AUDIOGRAPHIC CONFERENCE AND VIDEOCONFERENCE TELESERVICES; 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

European Telecommunications Standards Institute