MX960 Switch Control Board Description
The Switch Control Board (SCB) provides the following functions:
- Powers on and powers off DPCs, FPCs, and MPCs
- Controls clocking, system resets, and booting
- Monitors and controls system functions, including fan speed, board power status, PDM status and control, and the craft interface
- Provides interconnections to all the DPCs, FPCs, and MPCs within the chassis through the switch fabrics integrated into the SCB
The Routing Engine installs directly into a slot on the SCB (see Figure 1).
Figure 1: SCB
SCB Slots
You can install up to three. The SCBs install vertically into the front of the chassis in the slots labeled 0, 1, and 2/6. If any slots are empty, you must install a blank panel.
SCB Redundancy
SCBs installed in slots 0 and 1 provide nonredundant fabric connections. An SCB installed in slot 2/6, in conjunction with SCBs in slots 0 and 1, provides redundant fabrics, but the Routing Engine installed on it receives no power and provides no additional routing functions. If no SCB is installed in slot 2/6, you must install a blank panel in the slot (see Table 1).
Table 1: SCB Slot Mapping and Functionality
Functionality | Slot 0 | Slot 1 | Slot 2/6 |
|---|---|---|---|
Full fabric | SCB Routing Engine | SCB | – |
Full fabric and redundant Routing Engine | SCB Routing Engine | SCB Routing Engine | – |
Redundant fabric and Routing Engine | SCB Routing Engine | SCB Routing Engine | SCB |
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, FPCs, and MPCs
- 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, FPCs, and MPCs
- Circuits for chassis management and control
- Power circuits for the Routing Engine and SCB
- LEDs—Provide status
