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    Running a Y.1731 Loopback

    Use this procedure to run a Y.1731 loopback from one UNI to another UNI.


    • MEPs and MIPs have been configured for the service.

    A Y.1731 loopback request at the local MEP causes a Loopback Message (LBM) to be sent to the remote MEP. The remote MEP responds to the LBM with a Loopback Reply (LBR). Unlike link trace messages, only the target MEP responds to the LBM.

    1. In the Network tree view, click on the Ethernet service where you want to perform the loopback.

      The Ethernet service appears in the Topology window.

    2. Right-click the UNI port that you want to be the initiator, select CFM Tests >Loopback to, and pick the responder port and then the number of LBMs to send. If you want the responder port to be shown with its IP address in this list, see Setting device display options.

      The initiator UNI port must be on a BTI7000 Series, a BTI800 Series, or a BTI718E device. The responder UNI port can be a port on any compliant device.

      When a loopback is initiated on a BTI7000 Series or a BTI800 Series network element, a window appears showing the ongoing results of the loopback. When a loopback is initiated on a BTI718E device, the window only appears after the loopback test has completed. In all cases, the window stays open for a period of time after the test has finished.

      The window shows the number of LBMs transmitted by the initiator and the number of LBRs received from the responder. For the BTI7000 Series network elements, the counts are reset to 0 each time a loopback test is run. For the BTI800 Series and BTI718E devices, the counts are not reset, and represent the loopback counts from the time the service was started.

    Modified: 2016-12-11