Using the Class 5 Services
Voice Gateways System Manual 83
A.2.8 Call Forward

Description: Available only when there are no calls active/in progress.

*#43# Informs about present Call Waiting indication tone configuration:
Three short beeps = off
Two long beeps = on
Table A-9: Call Forward Service
Action Event
*21*<telephone number># Enable Call Forward and do forward to <telephone number>.
Indication tone is heard.
#21# Deactivate Call Forward
Table A-8: Call Waiting Indication Tone Service
Action Event