Echo cancellation ...again

i have an new installation of FreePBX distro 14 with Asterisk 13, a Sangoma A200 card (2FXS + 2FXO + HWEC) and Sangoma phone S500. When i make a call through the FXO lines everything is OK, except that i can hear my voice “return” about 1 sec after. I do not have any hum or whine in the analog lines. I do not know if this is a “hardware echo cancellation” problem. Through SSH, I run dahdi_cfg -vv and return this

DAHDI Tools Version - 2.11.1

DAHDI Version: 2.11.1
Echo Canceller(s): HWEC

Channel map:

Channel 01: FXO Kewlstart (Default) (Echo Canceler: oslec) (Slaves: 01)
Channel 02: FXO Kewlstart (Default) (Echo Canceler: oslec) (Slaves: 02)
Channel 03: FXS Kewlstart (Default) (Echo Canceler: oslec) (Slaves: 03)
Channel 04: FXS Kewlstart (Default) (Echo Canceler: oslec) (Slaves: 04)

4 channels to configure.

Setting echocan for channel 1 to oslec
Setting echocan for channel 2 to oslec
Setting echocan for channel 3 to oslec
Setting echocan for channel 4 to oslec

Is there any way to reduce or, even better, to stop this symptom?


Thank you very much for your answer. I believe that there is a problem with the card and the HWEC is not working. I will contact Sangoma support to resolve this.