Specifications

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Cisco 1751 Router Software Configuration Guide
OL-1070-01
Example
The following example configures an FXO voice port for a terminating impedance of 600 ohms:
voice port 0/0
impedance 600r
input gain
To configure a specific input gain value, use the input gain voice-port configuration command. Use the
no form of this command to disable this feature.
input gain value
no input gain value
Syntax Description
Default
0 dB.
Command Mode
Voice-port configuration.
Usage Guidelines
A system-wide loss plan must be implemented using both input gain and output attenuation
commands. Other equipment (including PBXs) in the system must be taken into account when creating
a loss plan. The default value for this command assumes that a standard transmission loss plan is in
effect, meaning that, normally, there must be –6 dB of attenuation between phones. Connections are
implemented to provide –6 dB of attenuation when the input gain and output attenuation commands
are configured with the default value of 0.
You cannot increase the gain of a signal going out into the PSTN, but you can decrease it. Therefore, if
the voice level is too high, you can decrease the volume by either decreasing the input gain value or by
increasing the output attenuation.
You can increase the gain of a signal coming into the router. If the voice level is too low, you can
increase the input gain.
Example
The following example configures a 3-dB gain for the receiver side of the interface:
voice port 0/0
input gain 3
Related Commands
output attenuation
value Amount of gain in decibels (dB) to be inserted at the receiver side of
the interface. Acceptable value is any integer from –6 to 14.