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Circuit Pack Descriptions
Issue 1
December 1997
7-69
23G/23G-U OLIU Quick Reference Summary
7
Transmit Functions
7
The major transmit functions of the 23G/23G-U OLIU circuit pack are as follows:
■
Selects 12 STS-1 signals from the TSI circuit packs
■
Adds SONET transport overhead
■
Byte-interleaves and scrambles the STS-1 signals to produce an STS-12
signal
■
Modulates a laser transmitter to produce an OC-12 signal.
Receive Functions
7
The major receive functions of the 23G/23G-U OLIU circuit pack are as follows:
■
Receives an OC-12 optical signal and converts an OC-12 signal to an
electrical STS-12 signal
■
Extracts STS-12 clock and retimes the received data
■
Demultiplexes the STS-12 signal into 12 STS-1 signals
■
Extracts and processes the STS-1 transport overhead
■
Processes the STS-1 pointer and frame-synchronizes the STS-1 signals
■
Processes the receive clock and provides a loop-timing clock to the TGS
circuit packs.
Control Functions
7
Control functions are as follows:
■
Protection switching for TSI circuit packs
■
Inventory information (
CLEI code, date of manufacture, etc.).
Maintenance Signal Functions
7
The 23G/23G-U OLIU major maintenance signal functions are as follows:
■
Inserts and detects STS-1 path AIS
■
Inserts STS-1 path unequipped signal
■
Inserts and detects OC-12 line AIS
■
Inserts and detects OC-12 line FERF
■
Detects OC-12 line failures (LOS, LOF, AIS, and BER)
■
Detects OC-12 line signal degrade BER.