Lucent Technologies DDM-2000 OC-3, User & Service Manual

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363-206-285
Circuit Pack Descriptions
Issue 3 June 2001 7-141
27G-U/27G2-U OLIU Circuit Pack Description 7
Purpose of Circuit 7
The 27G-U/27G2-U OLIU circuit pack provides the transmit and receive line
termination functions for two OC-1 signals. The 27G-U/27G2-U OLIU performs
the optical/electrical conversion between two optical carrier level 1 (OC-1) and
STS-1 signals and provides SONET transport overhead access. The 27G-U/
27G2-U OLIU also provides routing of the STS-1s between the OC-1 interfaces
and other main and function unit slots in the shelf as well as VT1.5/STS-1 add/
drop and ring capabilities. When used to perform VT1.5 add/drop or ring
capabilities, STS-1 path overhead access is also provided.
27G-U/27G2-U OLIU Faceplate Indicators 7
The 27G-U/27G2-U OLIU circuit pack faceplate indicators are shown in
Figure 7-49.
The red FAULT LED lights on detection of circuit pack hardware failure. In the
event of an incoming OC-1 signal failure, this LED will flash on and off.
The green ACTIVE LED lights when the circuit pack is active (carrying service).
A faceplate-mounted universal optical connector allows the 27G-U/27G2-U OLIU
to accept fiber terminated with
ST , SC, or FC connectors. The 27G-U/27G2-U
OLIU comes with a 0 dB ST buildout. A 10 dB attenuator is required for loopback
testing. The 27G-U/27G2-U OLIU operates over single mode fiber. Various
combinations of buildout attenuators and connectors are also available. See
Section 10, "Technical Specifications," for a list of universal buildout attenuators.