This object is used to configure the loopback mode of the
interface.
valid values are -
'noLoop' - No Loopback present.
'otherLoop' - A loopback of type other than rest of types
defined in this enumeration.
'diagnosticLoop' - This is an internal loopback, where the
data stream is looped from the transmit
to receive section. It is used for
hardware debug, bring-up and diagnostics.
'lineLoop' - In this mode, the receive data stream is
looped back to the transmit side.