Specifications

Chapter 10 - Voice Transmissions User Gain
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Mediatrix 4100
 To enable Comfort Noise:
1. In the voiceIfMIB, locate the voiceIfTable group.
2. Define the type of comfort noise in the voiceIfG711ComfortNoiseGenerationEnable variable.
The following settings are available:
3. Restart the Mediatrix 4100 so that the changes may take effect.
User Gain
The user gain allows you to modify the input and output sound level of the Mediatrix 4100.
You can compensate with the user gain if there is no available configuration for the country in which the
Mediatrix 4100 is located. Because the user gain is in dB, you can easily adjust the loss plan (e.g., if you need
an additional 1 dB for analog to digital, simply put 1 for user gain input).
 To set user gain variables:
1. In the voiceIfMIB, locate the voiceIfTable group.
2. Define the following variables:
• voiceIfUserInputGainOffset: User input gain offset in dB (from analog to digital).
• voiceIfUserOutputGainOffset: User output gain offset in dB (from digital to analog).
Values range from -30 dB to +20 dB. However, going above +6 dB may introduce clipping/distortion
depending on the country selected. Under -24 dB, you will not have much signal either.
3. Restart the Mediatrix 4100 so that the changes may take effect.
Table 108: Comfort Noise Settings
Setting Description
disable CNG disabled.
whiteNoise CNG enabled – white noise.
customNoise CNG enabled – custom noise. More elaborated background noise that
sounds better than white comfort noise.
Caution: Use these settings with great care. Media5 recommends not to modify the user gain variables
unless absolutely necessary because default calibrations may not be valid anymore.
Modifying user gains may cause problems with DTMF detection and voice quality – using a high user gain
may cause sound saturation (the sound is distorted). Furthermore, some fax or modem tones may not be
recognized anymore. The user gains directly affect the fax communication quality and may even prevent a
fax to be sent.
In the Unit Manager Network Administration Manual, refer to chapter Ports Parameters, section Port
Configuration Window.