Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Navigation
Guide That Contains This Content
[+] Expand All
[-] Collapse All

    Locate Loss of Signal and Loss of Frame Alarms

    Problem

    A loss of signal (LOS) or loss of frame (LOF) alarm indicates that a signal could not be detected at the T3 interface.

    Solution

    To locate the LOS or LOF alarm, check the connection between the router port and the first T3 network element. In the example network in Figure 1, the X indicates that there is a connection problem between Router 2 and the nearest T3 network element.

    Figure 1: Location of an LOS or LOF Alarm in a T3 Network

    Location of an LOS or LOF Alarm in
a T3 Network

    Note: Tx represents the transmit port and Rx represents the receive port.

    Sample Output

    user@router2> show interfaces t3-1/1/1 extensive
    [... Output truncated...]
     Active alarms  : LOF, LOS
      Active defects : LOF, LOS
       DS3 Media:            Seconds        Count  State
        PLL Lock                  0            0  OK
        Reframing               273            2  Defect Active
        AIS                       0            0  OK
        LOF                     273            2  Defect Active
        LOS                     273            2  Defect Active
    [...Output truncated...]
    

    Meaning

    The sample output shows that Router 2 (Rx) detected a cumulative LOS and LOF for 273 seconds. The defect was declared twice during that time.

    Published: 2013-02-25