pseudowire (PW)

The term pseudowire (PW) has been coined to describe the emulation of virtual circuits in IP networks. Pseudowire emulates the lines over packet-switched networks and decouples the service from the underlying physical infrastructure. Pseudowire is also offered over carrier Ethernet and is typically implemented as Ethernet over MPLS( EoMPLS).

The Pseudowire Emulation Edge-to-Edge( PWE3) working group of the Internet Engineering Task Force ( IETF) defines pseudowire as a mechanism that emulates essential characteristics of a telecommunications service such as Frame Relay( FR), ATM, or Ethernet over packet-switched networks based on the IP protocol, Layer 2 Tunneling Protocol ( L2TP), and Multi-Protocol Label Switching (MPLS).

MPLS tunneling described by PWE3.

This allows network operators to transport Layer 2 services and connection-oriented legacy services over IP networks with relative ease.

Concept of PWE3 with Pseudowires between Provider Edges (PE).

The pseudowire technique involves packaging arbitrary data from voice or video into new unified data packets that can then be transported across the network. The pseudowire technique is not only used in core networks, but also in the access area. The services remain unchanged.