This variable represents the current state of the loopback
on the DS3 interface. It contains information about loopbacks
established by a manager and remotely from the far end.
The acLogicalDs3ConfigLoopbackStatus is a bit map represented as a
sum, therefore is can represent multiple loopbacks simultaneously.
The various bit positions are:
1 ds3NoLoopback
2 ds3NearEndPayloadLoopback
4 ds3NearEndLineLoopback
8 ds3NearEndOtherLoopback
16 ds3NearEndInwardLoopback
32 ds3FarEndPayloadLoopback
64 ds3FarEndLineLoopback