A.The tunnel that is not configured with the policy-class command acts as the default
B.EXP selection is between multiple tunnels to the same destination
C.There is no requirement for IGP extensions
D.Tunnels are configured using the policy-class command and carry multiple EXP values
E.It supports VRF traffic， IP-to-MPLS switching， and MPLS-to-MPLS switching

A.VPI 16
B.DLCI
C.VPI and VCI
D.circuit number
E.PVC and SVC