aka Virtual Private LAN Service
- PW o Pseudo-wires:
- LDP o Label Distribution Protocol
- Provider edge o PE: routers communicate for auto-discovery and signaling. Auto-discovery refers to the process of finding other PE routers participating in the same VPN or VPLS. Signaling is the process of establishing pseudo-wires (PW). The PWs constitute the "data plane", whereby PEs send customer VPN/VPLS traffic to other PEs.