4.3 Identifying Tones
158 User Manual
When Making Calls
While Off-hook
Busy Tone
Reorder Tone
The outside (CO) line you tried
to seize is not assigned or was
denied.
Ringback Tones
Single (3-s interval)
Double (3-s interval)
Single (5-s interval)
Double (5-s interval)
DND Tone
The dialled extension is
refusing incoming calls.
Indication Tones
Tone 1 (Call Waiting Tone)
Tone 2 (Call Waiting Tone)
Single
Double
Triple
1 s
15 s
1 s