363-206-305
Circuit Pack Descriptions
7-88
Issue 3 June 2000
28G-U/28G2-U OLIU Quick Reference Summary
7
Transmit Functions
7
Major transmit functions of the 28G-U/28G2-U OLIU circuit pack are as follows:
a. Selects and multiplexes VT-Gs into one STS-1 synchronous payload
envelope (SPE)
b. Receives up to 3 STS-1s from function slots
c. Adds SONET and STS-1 path transport overhead
d. Combines 3 STS-1s into STS-3
e. Scrambles the STS-3 signal to prepare for optical conversion
f. Uses a laser transmitter to produce a SONET standard OC-3 optical signal.
Receive Functions
7
The following are major receive functions of the 28G-U/28G2-U OLIU circuit pack:
a. Receives one SONET standard OC-3 optical signal and converts it to an
electrical STS-3 signal
b. Extracts transport and STS-3 path overhead
c. Creates 3 STS-1s from an STS-3 signal
d. Processes the STS-1 pointer and frame-synchronizes the STS-1 signals
e. Processes the VT1.5 pointers and frame-synchronizes the VT1.5 signal
f. Provides path protection switching
g. Provides VT1.5/STS-1 signal cross-connections
h. Sends VT-Gs to the DS1 circuit packs.
Control Functions
7
The major control functions are as follows:
a. Processes transport and path overhead
b. Stores inventory information (
CLEI
code, date of manufacture, etc.)
c. Supports VT and OC-3 signal degrade protection switching
d. Supports protection switching of circuit packs in the low-speed slots.
Maintenance Signal Functions
7
The major maintenance signal functions are as follows:
a. Inserts and detects OC-3 line and STS-1 and VT1.5 path AIS
b. Inserts STS-1 and VT1.5 path unequipped signal
c. Inserts and detects line far-end-receive.