EXFO FTB-8100 Series, User Manual

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PDH Tabs
SONET/SDH Application
311
E1/2M RX
Alarm Analysis
Note: Only AIS is available when the Framing is set to Unframed .
³
LOF
(Loss Of Frame): The LOF alarm indicates that three consecutive
incorrect frame alignment signals have been received.
³
RAI
(Yellow) (Remote Alarm Indication): The RAI alarm is declared
when bit 3 in timeslot 0 is set to “1”.
³
AIS
(Alarm Indication Signal): The AIS alarm is declared when an
unframed all-ones signal is received.
³
TS16 AIS
(TimeSlot 16 Alarm Indication Signal): The TS16 AIS alarm is
declared when timeslot 16 is received as all-ones for all frames of two
consecutive multiframes.
³
RAI MF (Remote Alarm Indication Multi-Frame): The RAI MF alarm is
declared when bit 6 of timeslot 16 of frame 0 is set to “1”.
³
LOMF (Loss Of MultiFrame): The LOMF alarm indicates that two
consecutive multiframes alignment signals (bits 1 through 4 of TS16 of
frame 0) have been received with an error.
³
CRC LOMF
(CRC Loss Of MultiFrame): The CRC LOMF indicates that
the first bit of the NFAS in frames 1, 3, 5, 7, 9 and 11 differ from 0, 0, 1, 0,
1 and 1 respectively. CRC LOMF is available when the framing is set to
PCM30 CRC-4 or PCM31 CRC-4 and is based on CRC-4 errors.
Note:
In most cases the CRC LOMF will be reported at the same time as LOF since
the CRC LOMF leads to a LOF as per ITU G.706.