Aastra OpenCom 100 series Quick Reference Manual page 43

Time axis in seconds
Audio Signals
Ringing signal
Internal busy tone
Internal dialling tone
External dialling tone/continuous tone
Positive acknowledgement tone
Negative acknowledgement tone
Special internal dialling tone
Special external dialling tone
Call-waiting signal
Special sensor signal
Ringer signals (analogue terminals)
External ringer signal*
Internal ringer signal
* The first ring is a single ring, and all subsequent rings are periodic double rings.
The tones and ringer signals mentioned above are valid for Germany; in other countries they may differ.
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