Layer 2 Vpn Architectures [Electronic resources] نسخه متنی

Chapter 3. Layer 2 VPN Architectures

This chapter covers the following topics:

Legacy Layer 2 virtual private network (VPN)

Any Transport over MPLS (AToM)

Layer 2 Tunnel Protocol version 3 (L2TPv3)

The previous chapter highlighted different Layer 2 VPN architectures proposed by the network industry and Internet Engineering Task Force (IETF) working groups. In the past few years, significant progress has been made both in designing the Layer 2 VPN protocol specifications and realizing such innovations in a suite of new products. Pseudowire emulation serves as the fundamental building block for different Layer 2 VPN architectures.

A handful of network equipment vendors have developed products that support various levels of pseudowire emulation. The deployment of pseudowire emulation has started growing in the service provider space.

As part of the Unified VPN Suite Solution offering, Cisco IOS Software introduces two flavors of pseudowire emulation:

AToM

L2TPv3

To understand the functionalities and characteristics pertaining to these products, you need to first know the inherent properties and operations of the traditional, or legacy, Layer 2 VPNs.