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Cisco ATA 186 and Cisco ATA 188 Analog Telephone Adaptor Administrator’s Guide (SIP)
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Chapter5 Parameters and Defa ults
Optional Feature Parameters
Note Only positive values can be configured to the Cisco ATA 186. For negative values, use the 16-bit
2’s-complement value. For example, enter -1 as 65535 or 0xffff.
•freq[1] is the transformed frequency of the second frequency component (-32768 to 32767).
•level[0] is the transformed amplitude of the first frequency component (-32768 to 32767).
•level[1] is the transformed amplitude of the second frequency component (-32768 to 32767).
•steady controls whether the tone is constant or intermittent. A value of 1 indicates a steady tone and
causes the CiscoATA to ignore the on-time and off-time parameters. A value of 0 indicates an on/off
tone pattern and causes the CiscoATA to use the on-time and off-time parameters.
•on-time controls the length of time the tone is heard in milliseconds (ms) expressed as an integer
from 0 to 0xffff sample at 8000 samples/second.
•off-time controls the length of time between audible tones in milliseconds (ms) expressed as an
integer from 0 to 0xffff sample at 8000 samples/second.
•total-tone-time controls the length of time the tone is audible (0 to 0xffff). If this value is set to 0,
the tone will play until another call event stops the tone. For DialTone, Bus yTone, ReorderTone, and
RingBackTone, the configurable value is the number of 10 ms (100 = 1 second ) units.
For the other tones, the value is the number of samples at 8000 samples/second, where the following
information applies:
–
Frequency ranges from 0 to 4000 (Hz)
–
Transformed Frequency = 32767 · cos (2pi·Frequency/8000)
–
Amplitude ranges from 0 to 32767
–
Transformed Amplitude = A · 32767 · sin (2pi·Frequency/8000)
The scaling factor A determines the volume level of the tone. To calculate scaling factors, see the
“How to Calculate Scaling Factors” section on page5-43.
Note All tones are persistent (until the CiscoATA changes state) except for the call-waiting tone and the
confirm tone. The call-waiting tone, however, repeats automatically once every 10 seconds while the
call-waiting condition exists.
How to Calculate Scaling Factors
Use the following formula to calculate the scaling factor A:
A=0.5 * 10^((k+10-(n-1)*3)/20)
In this formulas, k is the desirable volume in dBm; n is the number of frequency components. The ^
symbol means to the order of.
Example
If a one-frequency component of -20 dBm volume level is desirable, the n:
A=0.5 * 10^((-20+10)/20) = 0.16