Specifications
xxvi
Cisco 1751 Router Software Configuration Guide
OL-1070-01
operation {2-wire | 4-wire}
no operation {2-wire | 4-wire}
Syntax Description
Default
2-wire.
Command Mode
Voice-port configuration.
Usage Guidelines
The operation command only affects voice traffic. Signaling is independent of two-wire versus
four-wire settings. If the wrong cable scheme is specified, the user might get voice traffic in only one
direction.
Configuring the operation command on a voice port changes the operation of both voice ports on a VIC.
The voice port must be shut down and then opened again for the new value to take effect.
This command does not apply to FXS or FXO interfaces because those are, by definition, two-wire
interfaces.
Example
The following example specifies that an E&M port uses a four-wire cabling scheme:
voice port 0/0
operation 4-wire
output attenuation
To configure a specific output attenuation value, use the output attenuation voice-port configuration
command. Use the no form of this command to disable this feature.
output attenuation value
no output attenuation
2-wire Two-wire E&M cabling scheme.
4-wire Four-wire E&M cabling scheme.