A.13

B.21

C.42

D.7

A.CSC-PE1 pops the BGP label and pushes two labels: a VPN label and an MPLS transport label.

B.PE1 pushes an LDP transport label.

C.CSC-CE2 pops the BGP label and pushes an LDP transport label.

D.CSC-PE2 pops the MPLS transport label and pushes a BGP label.

A.A routing protocol for exchanging customer routes with the CE

B.MPLS for exchanging labels with other provider core devices.

C.MP-BGP for exchanging customer routes with other PEs.

D.A label signaling protocol for defining transport tunnels between the PE and CE

A.8, 8, 6

B.8, 6, 4

C.24, 16, 8

D.16, 8, 4

E.8, 6, 3

A.On initialization and then every hello-interval.

B.Every 1 second.

C.Never.

D.Only after receiving LACP packets.