Juniper Networks MX240 manual SCB Components, SCB LEDs, Switch Control Board LEDs

Chapter 2: Hardware Components

SCB Components

Each SCB consists of the following components:

■Chassis management Ethernet switch.

■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.

■Switch fabric—Provides the switching functions for the DPCs.

■Control 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.

■Ethernet switch—Provides 1-Gbps link speeds between the Routing Engine and the DPCs.

■Circuits for chassis management and control.

■Power circuits for the Routing Engine and SCB.

■LEDs—Provide status (see “SCB LEDs” on page 13)

SCB LEDs

Three LEDs on the SCB indicate the status of the SCB. The LEDs, labeled FABRIC ACTIVE, FABRIC ONLY, and OK/FAIL, are located directly on the SCB. Table 9 on page 13 describes the functions of the SCB LEDs.

Table 9: Switch Control Board LEDs

Label	Color	State	Description
FABRIC	Green	On steadily	Fabric is in active mode.
ACTIVE
FABRIC	Green	On steadily	SCB operates in fabric-only mode.
ONLY
		Off	SCB operates in fabric/control board mode.
OK/FAIL	Green	On steadily	SCB is online.
	Off		SCB is offline.
	Red	On steadily	SCB has failed.

Host Subsystem ■ 13