MX2020 Backplane Description
Backplanes are located toward the rear of the chassis and form the rear of the card cage. They consist of one upper signal and power backplane located at the top of the chassis, and one lower signal and power backplane located at the bottom of the chassis. The Switch Fabric Boards (SFBs) connect both upper and lower backplanes. The adapter cards (ADCs) are carrier cards used to house the MPCs. The MPCs install into the top and bottom card cage backplanes from the front of the chassis and mate to the signal backplanes. The SFBs and CB-REs install into the middle from the front of the chassis. The PSMs and PDMs install into the top and bottom power backplanes from the rear of the chassis. The cooling system components also connect to the top and bottom backplanes.
The backplane performs the following major functions:
Data path—Data packets are transferred across the backplane between the MPCs through the fabric ASICs on the SFBs.
Power distribution—The router PDMs relay power from the feeds to the input of the PSMs through the power midplane. In addition, the output power from PSMs is distributed to the components of the chassis (MPCs, SFBs, and CB-REs), using the power backplane.
Control/Management path—The backplane provides management and control path connectivity among the various system components.