Subject: Protocol Action: 'Virtual Private LAN Service (VPLS) Using BGP for Auto-discovery and Signaling' to Proposed Standard

From: The IESG <[email-masked]>
Date: Wed, 05 Jul 2006 12:34:34 -0400

The IESG has approved the following document:

- 'Virtual Private LAN Service (VPLS) Using BGP for Auto-discovery and 
   Signaling '
   <draft-ietf-l2vpn-vpls-bgp-08.txt> as a Proposed Standard

This document is the product of the Layer 2 Virtual Private Networks Working 
Group. 

The IESG contact persons are Mark Townsley and Jari Arkko.

A URL of this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-l2vpn-vpls-bgp-08.txt

Technical Summary

This document describes the Virtual Private LAN Service (VPLS), also  known as
Transparent LAN Service and Virtual Private Switched Network  service.  The
service offers a Layer 2 Virtual Private Network (VPN);  however, in the case
ofVPLS, the customers in the VPN are connected  by a multipoint network, in
contrast to traditional Layer 2 VPNs,  which are point-to-point in nature. 
Thisdocument describes the  functions required to offer VPLS, a mechanism for
signaling a VPLS  using BGP, and rules for forwarding VPLS frames across a
packet  switched network.

Working Group Summary

The VPLS solutions have been one of great controversies within the  VPN
workinggroups ever since the PPVPN days.  There have been two  sets of
solutionsand
much debate on the relative merits of these  solutions.  An agreement was
reached that it is not really the choice  of signaling protocol that is the
major difference between the LDP  and BGP based solutions, but the kind of
environment they are  targeted at.  VPLS-LDP is aimed at a market of networks
built on  relatively small and functionally simple switches, while VPLS-BGP is 
primarily suited for use by high-end routers.  There is a  comparatively good
understanding for this agreement in the working  group.  Within the working
group there is no one that wants to go  over that debate again.  VPLS-BGP has
been through a number of  reviews, including reviews in the L2VPN working group
and the IDR  WG.  We know that Alex has requested that it shall be reviewed in 
routing directorate.

Protocol Quality

The protocol is implemented and deployed.  There is one vendor who is  known
tohave implemented, and widely deployed, the VPLS-BGP spec.  There is believed
to
be two other implementations, but that hasn't  been confirmed.  The number of
deployments is larger, but I don't  have figures.  We have not had any reviewer
stand up and saying there  is any need for major re-work.  This is most likely
attributable to  the fact that this specification is rather limited in scope, 
specifically: signaling and discovery of VPLS instances.

The specification has been reviewed by Alex Zinin, the IDR WG, and 
Mark Townsley.

IESG Note

The L2VPN Working Group produced two separate documents,
[RFC-draft-ietf-l2vpn-vpls-ldp] and [RFC-draft-ietf-l2vpn-vpls-bgp], that
ultimately perform similar functions in different manners. Be aware that each
method is commonly referred to as "VPLS" even though they are distinct and
incompatible with one another.