This document describes an architecture for Pseudo Wire Emulation Edge-to-Edge (PWE3). It discusses the emulation of services such as Frame Relay, ATM, Ethernet, TDM, and SONET/SDH over packet switched networks (PSNs) using IP or MPLS. It presents the architectural framework for pseudo wires (PWs), defines terminology, and specifies the various protocol elements and their functions. This memo provides information for the Internet community.