No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>Search


To have a better experience, please upgrade your IE browser.


Echo noise in FTTH due to the EC configuaraiton on Softswitch

Publication Date:  2018-03-23 Views:  295 Downloads:  0

Issue Description

Phone set A connected with Huawei ONT HG8121H further ONT connected with Huawei OLT MA5603T.

When B number (either Mobile phone or Landline phone) called to A number then B number hear echo noise.

Handling Process

Kindly collect the following infromation to locate the issue :

  • ·        Confirm with customer the version of the NE
  • ·        Please kindly explain the problem with simple network topology
  • ·        Is there any operation carried out recently or changes being made?
  • ·        How many customers is affected?
  • ·        Is this the only NE experience such issue?

Root Cause

  1. ·         If the AG subscribers hear echoes, it is because that the EC of the peer gateway is not complete.
  2. ·         If the subscribers of the peer gateway hear the echoes, it is because the EC of the AG is not complete


·         Cover the phone transmitter at the peer end where echo occurs. The echo persists. Therefore, the echo is not the acoustic echo. If it is the acoustic echo, the echo disappears when the phone transmitter is covered. In addition, when the peer phone calls a phone connected to anther device, no echo exists. Therefore, the echo is generated by the ONU.

·         Capture the H.248 signaling and analyze the signaling issued by the softswitch. It is found that the EC function is disabled. In the signaling, "tdmc/ec=off" indicates that the EC function is disabled. That is, no EC is implemented on the ONU, and therefore the peer subscribers can hear their own echoes.

·         Modify the data configuration on the softswitch, that is, enable the EC function. Then, perform the test. It is found that the call is normal, and neither side can hear their own echoes.