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How to configure gateways to minimize echo

Core Issue

Echo takes a number of forms. Who hears the echo and what device is at the other end are important characteristics. A talker hearing his own voice echoed is known as talker echo and is uncommon. A listener hearing the speakers voice echoed is the usual case. The echo can be minimally delayed with some loss, being perceived as Tunnel  voice or more seriously delayed with little, being perceived as a second discrete signal or echo.

Resolution

Echos are found in the analog tail circuit, not in the gateway. The gateway has an echo canceler that can attenuate manageable echos, but gateways cannot affect the root causes of the echo problems. An echo on a gateway can be fixed in three ways:

  • Ensure that the echo canceler is enabled with maximum coverage.        
  • Match output impedances and levels with the analog telecom equipment attached to the gateway analog voice ports.        
  • Provision the network in compliance with a fixed loss plan for IP voice gateways.

For more information, refer to Echo Analysis for Voice over IP. Also refer to numerous TAC CC solutions that can be found by searching on echo in TAC Case Collection.

Version history
Revision #:
1 of 1
Last update:
‎06-22-2009 06:08 PM
Updated by: