Layer 2 Vpn Architectures [Electronic resources] نسخه متنی

Chapter 6. Understanding Any Transport over MPLS

Label Distribution Protocol (LDP)

AToM operations

To provide Layer 2 VPN services over an IP/Multiprotocol Label Switching (MPLS) network infrastructure, the Internet Engineering Task Force (IETF) developed a series of solution and protocol specifications for various Layer 2 VPN applications, including pseudowire emulation. Based on the pseudowire emulation specifications, Any Transport over MPLS (AToM) is implemented as part of the Cisco Unified VPN Suite Solution. The Cisco solution also includes alternative pseudowire emulation using Layer 2 Tunnel Protocol Version 3 (L2TPv3). Chapter 3, "Layer 2 VPN Architectures," outlines the benefits and implications of using each technology and highlights some important factors that help network planners and operators determine the appropriate technology.

This chapter starts with an overview of LDP used by pseudowire emulation over MPLS, followed by an explanation of the protocol specifications and operations of AToM. You learn the general properties of the pseudowire emulation over MPLS networks specified in IETF documents. Additional features that AToM supports are also highlighted in this chapter.