I've previously been running v3.something of the firmware which allowed you to set the FXS port impedance to 370+620||210nF which was the standard all the instructions told you to use for a UK BT Line.
I've now upgraded to version 5.1.10 of the firemware and this option is no longer available. I've currently got it set to the default 600, but im getting some echo on the line.
Is this a bug that the 370+620 isnt available or should it now be set at a different level.
Thanks in advance.