Comparing, Designing, and Deploying VPNs

Chapter 3. Designing and Implementing AToM-Based Layer 2 VPNs

Any Transport over MPLS (AToM) allows the transport of Layer 2 protocols and connections over a Multiprotocol Label Switching (MPLS) backbone network. Transport over the MPLS backbone network is provided by encapsulating frames, cells, or Service Data Units (SDU), and transmitting them over a pseudowire.

If you have read Chapter 2, “Designing and Deploying L2TPv3-Based Layer 2 VPNs (L2VPN),” and you are thinking that all of this seems rather familiar, then you would be right—AToM pseudowires do a similar job to L2TPv3 pseudowires. The major difference is that L2TPv3 can transport Layer 2 protocols and connections over an IP backbone network, whereas AToM transports Layer 2 protocols ...