Circuit Pack Descriptions
7-48 Issue 8.0 July 2002
Synchronization Reference Protection. 7Synchronization reference switching is
done by selecting the primary or secondary synchronization reference signal from
the TG3 (DS1) circuit packs. The STS1E circuit pack monitors these
synchronization reference signals and can autonomously select the primary or
secondary. The LNCTL circuit pack can inhibit this autonomous selection and
make its own selection.
Fault Detection Circuitry 7
Monitoring and Testing. 7The board controller circuit monitors all the activities on
the circuit pack. The STS1E circuit pack has an in-service and out-of-service
built-in test capability. In-service testing is continuous. If an error occurs, the board
controller reports the error to the LNCTL circuit pack using the board controller
local area network (BCLAN). An out-of-service test is performed whenever the
STS1E circuit pack is inserted in a slot or when a reset is performed.
Loopbacks. 7The STS1E circuit pack provides one EC-1 loopback for each EC-1
signal. The loopback is implemented inside the transmit/receive byte processor
device. It bridges the output signal (transmitted towards the STSX-1 panel) back
into the transmit/receive byte processor input. The loopback is implemented in
response to CIT commands (via the SYSCTL and LNCTL circuit packs) and
controlled by board controller.
Performance Monitoring. 7The STS1E circuit pack provides
performance-monitoring circuitry for the following performance-monitoring
parameters:
â– EC-1 section severely errored frame seconds
â– EC-1 line coding violations
â– EC-1 line errored seconds
â– EC-1 line severely errored seconds
â– EC-1 line unavailable seconds
When an incoming EC-1 signal defect from the STSX-1 cross-connect panel is
detected, the STS1E circuit pack inserts STS-1 path AIS in each STS-1 tributary
of the 155.52 Mb/s signal transmitted toward the OC-48 TRMTR circuit pack.
When an incoming OC-48 signal defect is detected by the OC48 RCVR circuit
pack or an STS-1 loss of pointer is detected by the STS1E circuit pack in the
155.52 Mb/s signal received from the OC48 RCVR circuit pack, the STS1E circuit
pack inserts STS-1 path AIS in the EC-1 signal transmitted toward the STSX-1
cross-connect panel.
When an internal fault is detected, the STS1E circuit pack inserts STS-1 path AIS
in each STS-1 tributary of the 155.52 Mb/s signal transmitted toward the OC48
TRMTR circuit pack and in the EC-1 signals transmitted toward the STSX-1
cross-connect panel.
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