ÖNORM EN 300443-1 V 2.0.1:2001-06
Действует
Broadband Integrated Services Digital Network (B-ISDN) - Digital Subscriber Signalling System No. two (DSS2) protocol - B-ISDN user-network interface layer 3 specification for basic call/bearer control - Part 1: Protocol specification [ITU-T Recommendation Q.2931 (1995), modified]