User manual
Ring
A signal of specic duration and character that indicates to a user that a calling party is
engaged in an access attempt.
Ring Detect
The act of sensing that an incoming call is present by determining that the telephone switch
is providing a ringing signal to the voice board.
Ringback Tone
A tone advising the caller that a connection has been made and that a calling signal is being
applied to a telephone number or service point.
Special Information Tone
A tone advising the caller that the called number cannot be reached for reasons
other than "subscriber busy" or "congestion".
The tone may also be used in conjunction with recorded announcements to signify that what the
caller is about to hear is a recording. It should always be used to precede all call failure
announcements
Three Way Calling
A facility that allows a simultaneous call to be established between three different numbers.
Tone
An audible signal consisting of one or more superimposed frequencies with a dened cadence
and duration.
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User Manual
Public Switched Telephone Network (PSTN) Simulators