Layer 2 VPN Architectures

Chapter 1. Understanding Layer 2 VPNs

This chapter covers the following topics:

• Understanding traditional VPNs

• Introducing enhanced Layer 2 VPNs

A virtual private network (VPN) is a data network that utilizes a portion of a shared public network to extend a customer’s private network. This provides private communications between end users, such as remote offices and telecommuters. VPNs can be broadly categorized as either Layer 2 VPNs or Layer 3 VPNs.

This chapter begins with an overview of traditional VPNs, both Layer 2 and Layer 3, followed by a more in-depth look at enhanced Layer 2 VPN solutions over IP/Multiprotocol Label Switching (MPLS) and the factors that motivated their evolution. This chapter also covers the different types of ...