The router can have up to four FPCs installed horizontally in the front of the chassis, as shown in Figure 1. An FPC that houses four PICs weighs about 3 lb (1.5 kg). FPCs are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs). When you remove an FPC, forwarding operations halt for about 200 ms while the Packet Forwarding Engine flushes the shared memory buffers on the remaining FPCs.
To replace an FPC, perform the following procedures: