Juniper JUNOSE 11.2.X BGP AND MPLS, Configuration Manual

Page: 675 / 742

CHAPTER 14
VPWS Overview
This chapter describes virtual private wire service (VPWS) L2VPNs, and contains the
following sections:
• VPWS Overview on page 639
• BGP Signaling for L2VPNs Overview on page 641
•
VPWS Components Overview on page 642
•
VPWS and BGP/MPLS VPNs Overview on page 643
• BGP Multihoming for VPWS Overview on page 644
• Designated VE Device Selection for a Multihomed Site on page 646
•
Multihoming Reaction to Failures in the Network on page 648
•
VPWS Supported Features on page 649
• VPWS Platform Considerations on page 649
• VPWS References on page 650
VPWS Overview
VPWS L2VPNs employ layer 2 services over MPLS to build a topology of point-to-point
connections that connect end customer sites in a VPN. These L2VPNs provide an
alternative to private networks that have been provisioned by means of dedicated leased
lines or by means of layer 2 virtual circuits that employ ATM or Frame Relay. The service
provisioned with these L2VPNs is known as Virtual Private Wire Service (VPWS). VPWS
L2VPNs are sometimes called
Kompella L2VPNs. You configure a VPWS instance on
each associated edge router for each VPWS L2VPN.
Traditional VPNs over layer 2 circuits require the provisioning and maintenance of separate
networks for IP and for VPN services. In contrast, VPWS enables the sharing of a provider’s
core network infrastructure between IP and L2VPN services, reducing the cost of providing
those services.
VPWS also uses BGP as the signaling protocol, and consequently has a simpler design
and requires less provisioning overhead than traditional VPNs over layer 2 circuits. BGP
signaling also enables autodiscovery of L2VPN peers. VPWS is similar to BGP/MPLS
VPNs and VPLS in many respects, because all three types of services employ BGP for
signaling.
639 Copyright © 2010, Juniper Networks, Inc.