Ericsson 4187 Plus - Manual (Page 13)

13 Dialog 4187 Plus
Description
Tones and signals
The following different tones and signals are sent from the
telephone system to your phone.
Tone characteristics
The tones shown in this section are the most used tones
worldwide. Many markets use a differing tone for one or more
situations.
Dial tone
Special dial tone
Ring tone or queue tone every 4 seconds
Busy tone
Congestion tone
Number unobtainable tone
Call waiting tone
Intrusion tone
Conference tone every 15 seconds (to all parties)
Verification tone
Warning tone, expensive route