Layer 2 VPN Architectures: Understanding Any Transport over MPLS Anthony Pell 1 min read Jun 19, 2006 This article provides an overview of LDP, including LDP components and operations that are related to pseudowire emulation over MPLS along with an explanation of the control signaling and data switching details of AToM. Layer 2 VPN Architectures: Understanding Any Transport over MPLS Prev: The Linux System Administrator's Guide Next: Creating virtual private networks with tsocks and VTun