多项选择题
A. Layer 3 MPLS VPNs can forward only IP packets
B. Layer 2 MPLS VPNs can forward any network protocol
C. MPLS label paths are automatically formed based on Layer 2 frames
D. Layer 3 MPLS VPNs can forward any network protocol based on Layer 2 frames
E. In Layer 2 MPLS VPNS, the service provider controls the customer Layer 3 policies
单项选择题 Which of these technologies is characterized as being a multipoint Layer 2 VPN that connects two or more customer devices using Ethernet bridging techniques?（）
多项选择题 Which two of these are characteristics of Metro Ethernet? （）
多项选择题 Which two of these Metro Internet services map to E-LAN services that are defined by the MEF?（）