This parameter only applies to Sangoma A108 digital telephony boards.
it specifies which type of interface numbering will be applied on the A108
board. Possible values are:
- DEFAULT: interfaces on the A108 board are numbered as follows:
(1,5); (2,6); (3,7); (4,8)
- LINEAR: interfaces on the A108 board are numbered as follows:
(1,2); (3,4); (5,6); (7,8)