| Заглавие на английском языке | Integrated Services Digital Network (ISDN) - Signalling System No. 7 - ISDN User Part (ISUP) version 2 for the international interface - Part 17: Call Waiting (CW) supplementary service (CCITT Recommendation Q.733, section 1 (1992), modified); English version ETS 300356-17:1995 |