Layer 2 Vpn Architectures [Electronic resources] نسخه متنی

Chapter 5. WAN Data-Link Protocols

Introducing HDLC encapsulation

Introducing PPP encapsulation

Understanding Frame Relay

Understanding ATM

Before proceeding with a detailed examination of Layer 2 Tunneling Protocol Version 3 (L2TPv3) and Any Transport over MPLS (AToM), it is critical to understand the protocols that these tunneling mechanisms transport. The four WAN data link layer protocols covered include High-Level Data Link Control (HDLC), PPP, Frame Relay, and ATM.

This chapter introduces specific components of these Layer 2 protocols that are relevant to the L2TPv3 and AToM pseudowire protocols explored later in this book. For each of these protocols, the chapter examines the encapsulation format, any relevant control/management protocols that the pseudowire protocols might have to emulate, and any inherent traffic-management characteristics where applicable.