Edit the ../bristuff/zaptel/zaptel.h file and change the following settings:
    * Uncomment #define CONFIG_CALC_XLAW
    * Uncomment #define CONFIG_ZAPTEL_MMX !
    * Comment #define ECHO_CAN_KB1 and then UNCOMMENT the #define ECHO_CAN_MG2 so you are sure you will be using the MG2 echo canceller!