ETSI ETS 300 267-4

Integrated Services Digital Network (ISDN); Telephony 7 kHz and videotelephony 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 Edition: 1
European Telecommunications Standards Institute / 01-Apr-1998 / 32 pages