This variable indicates if this member can receive calls
from or make calls to other members of the same CUG.
When this variable is set to none(1), it means this
CUG member can receive calls from and make calls to
other members in the same CUG.
When this variable is set to incoming(2), it means this
member cannot receive incoming calls from other members
in the same CUG.
When this variable is set to outgoing(3), it means this
member cannot make calls to other members in the same CUG.