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Advance Data Sheet
T7633 Dual T1/E1 3.3 V Short-Haul Terminator
May 1998
92
Lucent Technologies Inc.
Alarms and Performance Monitoring
(continued)
Alarm Definition
(continued)
2.
Yellow alarm
or the
remote frame alarm
(FRM_SR1 bit 0).
This alarm is an indication that the line remote end is in a loss of frame alignment state. Indication of remote
frame alarm (commonly referred to as a yellow alarm) as for the different framing formats is shown in Table 39.
3.
Blue alarm
or the
alarm indication signal
(AIS).
The alarm indication signal (AIS), sometimes referred to as the blue alarm, is an indication that the remote end
is out-of-service. Detection of an incoming alarm indication signal is defined in Table 40.
Table 38. Red Alarm or Loss of Frame Alignment Conditions
Framing Format
Number of Errored Framing Bits That Will Cause a Red Alarm (Loss of Frame
Alignment) Condition
D4
2 errored frame bits (F
T
or F
S
) out of 4 consecutive frame bits if FRM_PR10 bit 2 = 1.
2 errored F
T
bits out of 4 consecutive F
T
bits if PRM_PR10 bit 2 = 0.
2 errored frame bits (F
T
or F
S
) out of 4 consecutive frame bits if FRM_PR10 bit 2 = 1.
2 errored F
T
bits out of 4 consecutive F
T
bits if FRM_PR10 bit 2 = 0.
3 errored frame bits (F
T
or F
S
) or channel 24 FAS pattern out of 12 consecutive frame bits.
2 errored F
E
bits out of 4 consecutive F
E
bits or, optionally, 320 or more CRC6 errored
checksums within a one second interval if loss of frame alignment due to excessive CRC-6
errors is enabled in FRM_PR9.
Three consecutive incorrect FAS patterns or three consecutive incorrect NOT FAS patterns;
or optionally, greater than 914 received CRC-4 checksum errors in a one second interval if
loss of frame alignment due to excessive CRC-6 errors is enabled in FRM_PR9.
SLC-96
DDS: Frame
ESF
CEPT
Table 39. Remote Frame Alarm Conditions
Framing Format
Remote Frame Alarm Format
Superframe: D4
Superframe: D4-Japanese
Bit 2 of all time slots in the 0 state.
The twelfth (12th) framing bit in the 1 state in two out of three consecutive super-
frames.
Bit 6 of time slot 24 in the 0 state.
An alternating pattern of eight 1s followed by eight 0s in the ESF data link.
Bit 3 of the NOT FAS frame in the 1 state in three consecutive frames.
Bit 6 of the time slot 16 signaling frame in the 1 state.
Superframe: DDS
Extended Superframe (ESF)
CEPT: Basic Frame
CEPT: Signaling Multiframe