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Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide for MGCP (version 3.0)
OL-4803-01
Chapter 5 Parameters and Defaults
Tone Configuration Parameters
• NumOfFreqs is the number of frequencies in the tone (1, 2, or 3). The frequencies can play
simultaneously or sequentially, depending on the Sequential setting.
• TFreq1, TFreq2, and TFreq3 are the transformed frequencies of the first, second, and third
frequencies, respectively. Calculate each value with the following formula:
32767 * cos (2 * pi * F/8000)
where F is the desired frequency in Hz. Set this value to 0 if the frequency does not exist.
The range of each value is –32768 to 32767.
For negative values, use the 16-bit 2’s complement value. For example, enter –1 as 65535 or as
0xffff.
• Tamp 1, Tamp2 and Tamp3 are the transformed amplitudes of the first, second and third frequencies,
respectively. Their values are calculated with the following formula:
32767 * A * sin(2*pi*F/8000)
A (amplitude factor) = 0.5 * 10^((k+10-(n-1)*3)/20)
where F is the desired frequency in Hz, k is the desired volume in dBm, and n is the number of
frequencies (If Sequential is set to 101, n is equal to 1). The ^ symbol means to the order of.
• NumOfOnOffPairs is the number of on-off pairs in the cadences of the tone (0, 1, 2, or 3). For a
steady tone, use 0.
If this value is 0, the OnTime1, OnTime2, OnTime 3, OffTime1, OffTime2, and OffTime3 values must
also be 0.
• OnTime1, OnTime2, and OnTime3 are the lengths of time that the first, second, and third on-off pairs
of a cadence play a sound, respectively. (See Figure 5-2 for a graphical representation.)
Specify each value as a number of samples with the sampling rate of 8 kHz. The range of each value
is 0 to 0xffff.
For example, for a length of 0.3 seconds, set a value to 2400.
• OffTime1, OffTime2, and OffTime3 are the lengths of silence after the sound of the first, second, and
third on-off pairs of a cadence, respectively.
Specify each value as a number of samples with the sampling rate of 8 kHz. The range of each value
is 0 to 0xffff.
For example, for a length of 0.3 seconds, set a value to 2400. (See Figure 5-2 for a graphical
representation.)
Figure 5-2 Cadence with Three On-Off Pairs
•
NumOfRepeats is the number of times that the first on-off pair of the cadence (specified by
OnTime1, OffTime1) repeats before the second on-off pair (specified by OnTime2, OffTime2) plays.
For example, if NumOfRepeats is 2, the first on-off pair will play three times (it will play once and
then repeat two times), then the second on-off pair will play.
OnTime_3
OffTime_3
99267
OnTime_1
OffTime_1
OnTime_2
OffTime_2
Sound
Silence