Automatic Gain Control (Agc) - AudioCodes Mediant 600 User Manual

11.6

Automatic Gain Control (AGC)

Automatic Gain Control (AGC) adjusts the energy of the output signal to a required level
(i.e., volume). This feature compensates for near-far gain differences. AGC estimates the
energy of the incoming signal (from the IP or PSTN, determined by the parameter
AGCRedirection), calculates the essential gain, and then performs amplification. Feedback
ensures that the output signal is not clipped. You can define the required Gain Slope in
decibels per second (using the parameter AGCGainSlop) and the required signal energy
threshold (using the parameter AGCTargetEnergy).
When the AGC first detects an incoming signal, it begins operating in Fast Mode, which
allows the AGC to adapt quickly when a conversation starts. This means that the Gain
Slope is 8 dB/sec for the first 1.5 seconds. After this period, the Gain Slope is changed to
the user-defined value. You can disable or enable the AGC's Fast Mode feature, using the
ini file parameter AGCDisableFastAdaptation. After Fast Mode is used, the signal should be
off for two minutes in order to have the feature turned on again.
To configure AGC, refer to ''Configuring the IPmedia Settings'' on page 78.
SIP User's Manual 570
Mediant 600 & Mediant 1000
Document #: LTRT-83305