Cisco GS7000 Installation And Operation Manual page 26

Chapter 1 General Information
Module
Optical Interface
Board
8
Description
The Optical Interface Board (OIB) provides all interconnections
between the modules in the housing lid to the RF amplifier module in
the housing base. Each module in the lid plugs directly into the OIB
through a connector header, a connector header and RF connectors, or
row of sockets depending on the module type. An input attenuator
pad is provided on the OIB for each optical receiver and Remote-PHY
device in the housing lid. Output attenuator pads are provided on the
OIB for each optical transmitter and Remote-PHY device in the
housing lid.