A、Cisco Express Forwarding （CEF） must be enabled as a prerequisite to running MPLS on a Cisco router.

B、Frame-mode MPLS inserts a 32-bit label between the Layer 3 and Layer 4 headers.

C、MPLS is designed for use with frame-based Layer 2 encapsulation protocols such as Frame Relay， but is not supported by ATM because of ATM fixed-length cells.

D、OSPF， EIGRP， IS-IS， RIP， and BGP can be used in the control plane.

E、The control plane is responsible for forwarding packets.

F、The two major components of MPLS include the control plane and the data plane.