To answer while hearing a callback ringing
To cancel (CCBS Cancel)
If you do not answer within a specified time period, this feature will be cancelled.
Availability of this feature depends on the ISDN service offered by your telephone
Sending a Call Waiting Tone (Call Waiting)
You can inform the called party that your call is waiting.
This feature is also known as Busy Station Signalling (BSS).
While hearing a busy tone
Depending on the other party's telephone, the "Off-hook Call Announcement (OHCA)"
and the "Whisper OHCA" features can be used. You can talk to the other party through the
speaker and the microphone (OHCA) or you only send a call announcement through the
handset (Whisper OHCA), if they are having another conversation using the handset.
Refer to "1.7.3 Receiving Call Waiting (Call Waiting/Off-hook Call Announcement [OHCA]/
1.2 Making Calls