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 Q.931 (1993), modified]; English version ETS 300403-1:1995
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 Q.931 (1993), modified]; English version ETS 300403-1:1995