User's Manual

Cisco High-Density Analog Voice and Fax Network Module
Configuration Tasks
15
Cisco IOS Release 12.2(2)XT and 12.2(8)T
To change parameters related to disconnect supervision, use the following commands as appropriate, in
voice-port configuration mode:
Command Purpose
Step 1
Router(config-voiceport)# battery-reversal
Enables battery reversal. The default is that battery
reversal is enabled.
• For FXO ports—Use the no battery-reversal
command to configure a loop-start voice port to not
disconnect when it detects a second battery reversal.
The default is to disconnect when a second battery
reversal is detected.
Note Also use the no battery-reversal command when
a connected FXO port does not support battery
reversal detection.
• For FXS ports—Use the no battery-reversal
command to configure the voice port not to reverse
battery when it connects calls. The default is to
reverse battery when a call is connected, then return
to normal when the call is over, providing positive
disconnect.
See also the disconnect-ack command (Step 7).
Step 2
Router(config-voiceport)# supervisory disconnect
(FXO only) Enables the PBX or PSTN switch to provide
STD. By default the supervisory disconnect command is
enabled.
Step 3
Router(config-voiceport)# disconnect-ack
(FXS only) Configures the voice port to return an
acknowledgment upon receipt of a disconnect signal. The
FXS port removes line power if the equipment on the FXS
loop-start trunk disconnects first. This is the default.
The no disconnect-ack command prevents the FXS port
from responding to the on-hook disconnect with a
removal of line power.