Integrated Services Digital Network (ISDN) - Digital Subscriber Signalling System No. one (DSS1) protocol - Signalling network layer for circuit-mode basic call control - Part 1: Protocol specification [ITU-T Recommendation Q.931 (1993), modified]
Information technology - Open Systems Interconnection - Conformance testing methodology and framework - Part 2: Abstract test suite specification— 38 стр.
Information technology - Telecommunications and information exchange between systems - Private Integrated Services Network - Circuit mode bearer services - Inter-exchange signalling procedures and protocol— 145 стр.
