Step 1: Log into yourunit using its IP:9999.
Step 2: By default the username is admin and the password is also admin unless changed.
Step 3: Once in the gateway click on the Advanced tab and select Line Settings on the left hand side.
Step 4: Under Volume Adjustment is where you can change settings make the phone quality better if you are hearing static/echo.
PSTN to(TX) affects static.
to PSTN (RX) affects echo.
Step 5: Apply the settings and test out the connection.
Repeat Step 4 and Step 5 if needed for optimal sound quality.