M320 Control Board (CB) Components
Each CB consists of the following components:
- PCI bus—Provides the interface to the Routing Engine.
- 1000Base-T Ethernet controller—Provides a 1-Gbps link between the Routing Engine and the on-board Fast Ethernet switch.
- Fast Ethernet switch—Provides a 100-Mbps Ethernet link to each FPC for Routing Engine data transfers.
- Three LEDs, located on the CB faceplate, indicate the status of the CB. Table 1 describes the functions of the CB LEDs.
- CB online/offline button, located on the CB faceplate.
Note: The online/offline button on the CB faceplate is currently nonfunctional.
- Circuits that control fans and other hardware components in the chassis.
- Internally-generated 19.44-MHz Stratum 3 reference clock for line timing.
- Two RJ-48 connectors for external clock inputs for 19.44-MHz
Stratum 3 reference clocks.
Note: For more information about configuring an interface transmit clock, see the JUNOS Network Interfaces Configuration Guide.
- Power circuits for the Routing Engine.
Table 1: M320 CB LEDs
