Juniper Networks MX480 - Manual (Page 54)

MX SCBE Slots
You can install one or two MX SCBEs. The MX SCBEs install horizontally into the front
of the chassis in the slots labeled
0 and 1 . If any slots are empty, you must install a blank
panel.
MX SCBE Redundancy
If two MX SCBEs are installed, one MX SCBE functions as the master MX SCBE and the
other as its backup. If the master fails or is removed, the backup restarts and becomes
the master.
MX SCBE Components
Each MX SCBE consists of the following components:
• I2C bus logic, used for low-level communication with each component
• Component redundancy circuitry
• Control Board/Routing Engine mastership mechanism
• Gigabit Ethernet switch that is connected to the embedded CPU complex on all
components
• External clock interface—Allows BITS or GPS clock source input to the centralized
timing circuit, or allows centralized timing to be output to BITS or GPS
• Switch fabric—Provides the switching functions for the DPCs, FPCs, and MPCs
• Control field-programmable gate array (FPGA)—Provides the Peripheral Component
Interconnect (PCI) interface to the Routing Engine
• 1000Base-T Ethernet controller—Provides a 1-Gbps Ethernet link between the Routing
Engines
• Circuits for chassis management and control
• Power circuits for the Routing Engine and SCBE
• LEDs—Provide status of the SCBE and clocking interface
Related
Documentation
MX480 Switch Control Board (SCB) Description on page 26 •
• MX480 Enhanced Switch Control Board LEDs on page 30
• Upgrading an MX480 SCB on page 177
MX480 Enhanced Switch Control Board LEDs
The FABRIC ACTIVE , FABRIC ONLY , and OK/FAIL LEDs indicate the status of the SCBE.
The BITS , GPS , and UTI LEDs, located next to the EXT CLK port, indicate the status of the
respective clocking interface. Table 7 on page 31 describes the functions of the Enhanced
MX SCB (MX SCBE) LEDs.
Copyright © 2013, Juniper Networks, Inc. 30
MX480 3D Universal Edge Router Hardware Guide