Midplane

The midplane is located toward the rear of the chassis and forms the rear of the card cage (see Figure 4). IOCs, SPCs, and SCBs install into the midplane from the front of the chassis, and the power supplies install into the midplane from the rear of the chassis. The cooling system components also connect to the midplane.

The midplane performs the following major functions:

• Data path—Data packets are transferred across the midplane between the IOCs and SPCs through the fabric ASICs on the SCBs.
• Power distribution—The power supplies are connected to the midplane, which distributes power to all the services gateway components.
• Signal path—The midplane provides the signal path to the IOCs, SCBs, SPCs, Routing Engine, and other system components for monitoring and control of the system.

Figure 4: Midplane