A.L2F B.PPTP C.Circuit cross-connect D.Draft-Martini-based VPNs E.Draft-Kompella-based VPNs
A.hdlc-ccc B.atm-cell-ccc C.cisco-hdlc-ccc D.ethernet-vlan-ccc E.ethernet-snap-ccc
A.Martini based VPN’s B.2547bis based VPN’s C.Sham link based VPN’s D.Virtual Router based VPN’s