A. Link-mode B. Dense mode C. Sparse mode D. Sparse-dense mode
A. MPLS LSP B. ATM tunnel C. GRE tunnel D. IPSEC tunnel E. L2TPv3 session
A. to create a partial mesh of VPN sites B. to remove MPLS from VPNs C. to create a point to multipoint topology D. to enable IPsec accross the VPN