363-206-305
Circuit Pack Descriptions
7-66
Issue 3 June 2000
22-Type OLIU Circuit Pack Descriptions
7
Purpose of Circuits
7
The 22-type OLIU circuit packs (22D-U, 22F/22F-U/22F2-U, and 22G-U/22G2-U/
22G3-U/22G4-U) perform the optical/electrical conversion between optical carrier
level 3 (OC-3) and STS-3 signals, multiplexing between STS-3 and three STS-1
signals and accessing SONET transport overhead. These circuit packs also
provide routing of STS-1 signals between the OC-3 interface and main slots in the
shelf.
The 22D-U OLIU offers short reach service over multimode fiber.
The 22F-type OLIUs offer intermediate reach service over multimode or single-
mode fiber.
The 22G-type OLIUs offer higher power optics than the other 22-type OLIUs. The
22G2-U/22G3-U/22G4-U OLIUs offer improved receiver overload sensitivity,
eliminating the need for an external attentuator. The 22G3-U and the 22G4-U use
a SONET-compliant long-reach transmitter.
In the FiberReach shelf, these circuit packs are used in the function unit slots only,
and may only be used when the main slots are equipped with OC-3 or OC-12
OLIUs.
22-Type Faceplate Indicators
7
Examples of the 22-type OLIU circuit pack faceplate indicators are shown in
Figure 7-26 (22D-U), Figure 7-27 (22F-U), and Figure 7-28 (22G-U).
The red FAULT LED lights on detection of circuit pack hardware failure. In the
event of an incoming 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 22D-U OLIU to accept
fiber terminated with ST, SC, or FC connectors. The 22D-U and the 22G2-U/
22G3-U/22G4-U OLIUs come with a 0 dB ST buildout. For the 22D-U and the
22G-U OLIUs, a 10 dB attenuator is required for loopback testing. The 22G2-U/
22G3-U/22G4-U OLIUs do not need an external attentuator for loopback testing.
The 22D-U OLIU circuit pack provides cost effective interconnect for intra-office
applications and is used only for DDM-2000 OC-3 and OC-12 or
SLC
-2000
interworking over multimode fiber.
Various combinations of buildouts and connectors are also available. See Chapter
10, "Technical Specifications," for a list of universal buildout attenuators.
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