Understanding the Control Board
Purpose
Inspect the Control Boards to ensure that control and monitoring functions occur for the router.
What Is the Control Board
The Control Board works with an adjacent Routing Engine in the host subsystem on M320 and T320 routers and the T640 routing node to provide control and monitoring functions. These functions include determining Routing Engine mastership, controlling power, performing reset and SONET clocking for the other router components, monitoring and controlling fan speed, and monitoring system status using I2C controllers.