Maintenance Description
Issue 8.0 July 2002
9-77
back at the cross-connect panel and the DS3 circuit pack monitors
each DS3 signal. If only one parity bit error is detected within 1
second, the test passes.
Rather than checking parity, the STS1E and OC3 (1.3 STD) circuit
packs use special test signals with a known content to verify the
continuity of each transmission path.
— To verify the parity error rate of each transmission path, each DS3
circuit pack monitors each DS3 signal from the cross-connect panel
(or equivalent) for errors over a 4-second period. If no errors are
detected in the 4-second period, the test passes.
â– Regenerator Self-Test:TheFAULT-Test-Auto Turnup input verifies
each individual OC48 REGENR circuit pack in an FT-2000 OC-48
Repeater Bay. The regenerator test verifies the transmission and fault
isolation capabilities of an OC48 REGENER circuit pack.
For the regenerator test, the output of each OC48 REGENR circuit pack to
be tested must be looped back to its input with a single-mode fiber jumper
and a lightguide buildout in the optical path simulating the outside plant
loss (Figure 9-27).
Figure 9-27. Regenerator Self-Test
The OC48 REGENR circuit pack inserts an AIS signal embedded with
F1-bytes (site address and line status codes) in the outgoing high-speed
signal. The OC48 REGENR circuit pack reads the F1-bytes on the
incoming high-speed signal. If the F1-bytes line status codes are read and
no conditions are observed that would set the outgoing F1-byte to anything
other than normal, the test passes.
Internal test signal
Monitor
Local
OC48 REGENR
Multiplexing Direction
Loopback
Fiber
Demultiplexing Direction
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