SWG-2008 - echo and slurred speech

Hi, I ask for help, there is a gateway in conjunction with the Asterisk server:
Product Name: SWG-2008
Model Description: WCDMA: 900 / 2100MHz
GSM: 900 / 1800MHz
Software Version: 2.1.18
Hardware Version: 1.0

When there is an incoming call to the GSM gateway to my extension number 101, the client hears an echo and not intelligible speech, tell me how to solve this problem, tried to change the Txgain, Txdgain, Rxgain parameters .. nothing helped.

For example, there is one more gateway in the same place GOIP8, the sound is clear and there is no echo.
I ask for help, thanks!

Hi vlymar
please contact my skype:dario.hu2 and prepare teamview for remote help.

Do you guys please post what you did to solve the problem? we have several gateways with echo on calls.
BR,
MC

Hello,
Can you guys please post what you did to solve the problem? I have several gateways/different customers with the same echo problem.
BR,
MC

Hi vlymar,
I´m experiencing the same issue, did you resolve the problem?

Please add my skype:dario.hu2 and prepare remote for help.