Integrated Services Digital Network (ISDN) - Call Forwarding Busy (CFB) supplementary service - Service description (Endorsement of the English version EN 300199 V 1.2.1 (2001-06) as German standard)— 1 стр.
Telecommunications Management Network (TMN) - Functional specification of Customer Administration (CA) on the Operations System/Network Element (OS/NE) interface - Part 1: Single line configurations
Integrated Services Digital Network (ISDN) - Selective Call Forwarding (SCF) supplementary services (unconditional, busy and no reply) - Service description
