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 Remote Error Indication Line Errors

    A remote error indication (REI) is sent upstream to signal an error condition. There are two types of REI alarms:

    • Remote error indication line (REI-L) is sent to the upstream LTE when errors are detected in the B2 byte.
    • Remote error indication path (REI-P) is sent to the upstream PTE when errors are detected in the B3 byte.
    1. Example of Only an REI-P Counter Incrementing
    2. Example of Both REI-L and REI-P Counters Incrementing

    Example of Only an REI-P Counter Incrementing

    Problem

    Figure 1 shows an REI-P Counter Incrementing. The wavy line indicates that there is a line error in the section between ADM 1 and ADM 2.

    Solution

    All diagnostics are from the perspective of Router 2 (the Juniper Networks router).

    Figure 1: Example of a Router Receiving Only an REI-P Counter Incrementing

    Example of a Router Receiving Only
an REI-P Counter Incrementing

    Meaning

    In Figure 1, the progression of events occurring after the failure is as follows:

    1. ADM 1 detects parity errors in the B1 byte.
    2. ADM 1 sends an REI-L upstream to ADM 2.
    3. Router 1 detects parity errors in the B3 byte.
    4. Router 1 sends an REI-P upstream to Router 2.
    5. Router 2 only sees an REI-P incrementing counter.


    Example of Both REI-L and REI-P Counters Incrementing

    Problem

    Figure 2 shows both REI-L and REI-P Counters Incrementing. The wavy line indicates that there is a line error in the section between Repeater 2 and Router 2.

    Solution

    All diagnostics are from the perspective of Router 2 (the Juniper Networks router).

    Figure 2: Example of a Router Receiving Both An REI-L and REI-P Counter Incrementing

    Example of a Router Receiving Both
An REI-L and REI-P Counter Incrementing

    Meaning

    In Figure 2, the progression of events occurring after the failure is as follows:

    1. Repeater 2 detects some parity errors in the B1 byte from a corrupted SONET frame.
    2. ADM 2 detects parity errors in the B2 byte.
    3. ADM 2 sends an REI-L upstream to Router 2.
    4. Router 1 detects parity errors in the B3 byte.
    5. Router 1 sends back an REI-P upstream to Router 2.
    6. Router 2 sees incrementing REI-L and REI-P errors.

    Published: 2012-06-29