Description: The loop status of E1 port, the meaning of various enumeration valuesis as follows: remote-loop(2), in the status of remote loop local-loop(4), in the status of local loop rmt-lcl-loop(6), in remote and local loop status simultaneously payload-loop(8), in the status of payload loop rmt-payload-loop(10), in remote and payload loop status simultaneously lcl-payload-loop(12), in local and payload loop status simultaneously rmt-lcl-payload-loop(14), in local, remote and payload loop status simultaneously no-loop(16) not in loop status There are three types of loop: local loop, remote loop and payload loop which are not exclusive to one another, and can exist simultaneously.