Patton electronics 6511RC, Administrator'S Reference Manual

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15 • SDH Model 6511RC Switch Matrix Administrators’ Reference Guide
138 Alarm Status
Path status alarm
When a Path alarm is present in the SDH Line, the icon will change from green to red. Clicking on the icon
takes the user to the SDH Path STATUS ALARMS page. A Path alarm is activated upon detection of Path LOP,
Path AIS, Path RDI, Path Unequipped, Path Signal Label Mismatch, or Path Trace Mismatch, in addition, it dis-
plays the Received Path Signal Label and the Received Path Trap.
Figure 75. SDH Path STATUS ALARMS window
Path LOP
A Loss of Pointer (LOP) is declared when either a valid pointer is not detected in eight consecutive frames, or
when eight consecutive frames are detected with the New Data Flag (NDF) set to 1001 without a valid concat-
enation indicator. LOP state is cleared when either a valid pointer with a normal NDF set to 0110, or a valid
concatenator indicator is detected for three contiguous frames.
Path AIS
Path AIS is defined as all-ones in the TU or AU pointers. SOH is not affected. Path AIS is generated to replace
the normal traffic signal when it contains a defect condition in order to prevent cascaded downstream failures
being declared or alarms being raised.
Path RDI
Path RDI formerly called path-FERF (Far End Remote Fail). This signal is returned to the transmitting TE
when the far end detects a Loss of Signal, Loss of Frame, AIS, Trace Identifier Mismatch, or Path Unequipped.
Path Unequipped
The Path Unequipped alarm is initiated when the path signal label byte C2 is set to all zeroes for at least five
consecutive frames.