6-12
Cisco AS5350 and Cisco AS5400 Universal Gateway Software Configuration Guide
OL-3418-02 B0
Chapter 6
Configuring Voice over IP
Configuring Basic VoIP
Tip
Consult the references at the end of the chapter before you create a dial-peer configuration table. See
also Voice over IP for the Cisco AS5300, available online at
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/120newft/120t/120t3/voip5300/
Configuring Nextport Echo Canceller Control (optional)
The AS5350, AS5400, and AS5400HPX Universal Gateways can detect 2100Hz tones, received in
G.711 encoded VoIP packets. Customers can enable Nextport Voicecap to control the echo canceller
when 2100Hz 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
It is not recommended 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 2100Hz answer tones from the IP side. This
setting is required in IOS Release 12.3T
•
v2 = 512
This setting enables the 250 millisecond silence detection. 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:
Syntax:
router(config)#voicecap entry <name> <parameter list>
Example:
router(config)#voicecap entry npecho_ctrl v2=512 v51=32769
2.
Apply the Voicecap entries to the voice port by entering the following CLI command:
Syntax:
router(config)#voicecap configure <name>
Example:
router(config)#voicecap configure npecho_ctrl
