Configuring Voice over IP
Configuring Basic VoIP
12
Cisco AS5350XM and Cisco AS5400XM Universal Gateways Software Configuration Guide
Configuring Nextport Echo Canceller Control (optional)
The AS5350XM and AS5400XM universal gateways can detect 2100Hz tones, received in G.711
encoded VoIP packets. Customers can enable Nextport Voicecap to control the echo canceller when
2100-Hz tones are received in G.711 encoded VoIP packets from either the PSTN or IP side of the
network.
Note
Nextport control over the echo canceller is only possible in G.711 codec modes.
Note
We do not recommend that you enable Nextport control over the echo canceller in conjunction with
modem-pass-through.
You enable IP tone detection and Nextport control over the echo canceller using CLI commands, but you
must first set the following two Voicecap parameters to enable these features:
•
v51 = 32769
This setting enables IP side tone detection/notification and allows Nextport to disable the nonlinear
processor (NLP) or the echo canceller upon reception of 2100-Hz answer tones from the IP side.
This setting is required in Cisco IOS Release 12.3T and later.
•
v2 = 512
This setting enables detection of the 250 millisecond silence . This setting is optional. When this
setting is used in conjunction with the v51 = 32769 setting, Nextport restores the echo canceller to
its original state after it detects the 250-millisecond silence.
The following example shows how to enable Nextport control over the echo canceller by creating a
Voicecap entry and applying it to the voice port.
1.
Create Voicecap entries by entering the following CLI command:
Step 3
voice-port
slot
/
port
Example:
Router(config)# voice-port 2/1
Enters voice-port configuration mode and
identifies a slot and port for configuration
parameters.
Step 4
echo-cancel enable
Example:
Router(config-voiceport)# echo-cancel
enable
Enables the cancellation of voice that is sent out
the interface and received back on the same
interface.
Step 5
echo-cancel coverage
{
24
|
32
|
48
|
64
}
Example:
Router (config-voiceport)# echo-cancel
coverage 24
Adjusts the echo canceller by the specified number
of milliseconds.
•
The default is 64.
Step 6
exit
Example:
Router(config-voiceport)# exit
Exits voice-port configuration mode and returns to
global configuration mode.
Command or Action
Purpose
