Vt/tu – EXFO FTB-800 Series for FTB-1 User Manual
Page 298
Test Results
288
FTB-700G/800 Series
Alarms/Errors
VT/TU
Alarms
AIS-V (Alarm Indication Signal - VT) - SONET
TU-AIS (Tributary Unit - Alarm Indication Signal) - SDH
RX: V1 and V2 bytes for the VT/TU path contain an all-ones pattern in
three (SONET) / five (SDH) consecutive superframes.
TX: Generates an all-ones pattern for the V1 and V2 bytes of the VT/TU
path and payload.
LOP-V (Loss Of Pointer - VT) - SONET
TU-LOP (Tributary Unit - Loss Of Pointer) - SDH
RX: A valid pointer is not found in N consecutive superframes (where
8 N 10), or if N consecutive NDFs (“1001” pattern).
TX: Generates a non-valid pointer.
RDI-V (Remote Defect Indication - VT) - SONET
LP-RDI (Tributary Unit - Remote Defect Indication) - SDH
RX: Bit 8 of the V5 byte contains “1” in five consecutive VT/TU
superframes while bits 6 and 7 of the Z7 (SONET) / K4 (SDH) byte
contain the “00” or “11” pattern.
TX: Generates “1” for the bit 8 of the V5 byte and a “00” pattern for bits
6 and 7 of the Z7 (SONET) / K4 (SDH) byte.
RFI-V (Remote Failure Indication - VT) - SONET
LP-RFI (LOP - Remote Failure Indication) - SDH, available with VC-11
only.
RX: Bit 4 of the V5 byte contains “1” in five consecutive superframes.
TX: Generates “1” for the bit 4 of the V5 byte.