VPN Services: Layer 2 or Layer 3? Which Service is Preferred by Enterprises and Why?

This paper focuses on enterprise requirements and opinions regarding Layer 2 and Layer 3 networking services. Specifically, the services discussed in this report are Ethernet (Layer 2) and IP (Layer 3). Additionally, VPNs based on these services are highlighted, including VPLS (RFC 4762) and IP-VPNs (RFC 4364), both of which leverage an MPLS network. While IP-VPNs are ubiquitous, VPLS (also described as carrier Ethernet VPNs) are just starting to become available in certain markets.