Network Working Group L. Andersson, Ed.
Request for Comments: 4664 Acreo AB
Category: Informational E. Rosen, Ed.
Cisco Systems, Inc.
September 2006
Framework for Layer 2 Virtual Private Networks (L2VPNs)
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This document provides a framework for Layer 2 Provider Provisioned
Virtual Private Networks (L2VPNs). This framework is intended to aid
in standardizing protocols and mechanisms to support interoperable
L2VPNs.
Andersson & Rosen Informational [Page 1]
RFC 4664 Framework for Layer 2 VPNs September 2006
Table of Contents
1. Introduction ....................................................3
1.1. Conventions Used in This Document ..........................3
1.2. Objectives and Scope of the Document .......................3
1.3. Layer 2 Virtual Private Networks ...........................3
1.4. Terminology ................................................4
2. Models ..........................................................5
2.1. Reference Model for VPWS ...................................5
2.1.1. Entities in the VPWS Reference Model ................5
2.2. Reference Model for VPLS ...................................6
2.2.1. Entities in the VPLS Reference Model ................8
2.3. Reference Model for Distributed VPLS-PE or VPWS-PE .........9
2.3.1. Entities in the Distributed PE Reference Models .....9
2.4. VPWS-PE and VPLS-PE ........................................9
3. Functional Components of L2 VPN .................................9
3.1. Types of L2VPN ............................................10
3.1.1. Virtual Private Wire Service (VPWS) ................10
3.1.2. Virtual Private LAN Service (VPLS) .................10
3.1.3. IP-Only LAN-Like Service (IPLS) ....................11
3.2. Generic L2VPN Transport Functional Components .............11
3.2.1. Attachment Circuits ................................11
3.2.2. Pseudowires ........................................12
3.2.3. Forwarders .........................................14
3.2.4. Tunnels ............................................15
3.2.5. Encapsulation ......................................16
3.2.6. Pseudowire Signaling ...............................16
3.2.6.1. Point-to-Point Signaling ..................18
3.2.6.2. Point-to-Multipoint Signaling .............18
3.2.6.3. Inter-AS Considerations ...................19
3.2.7. Service Quality ....................................20
3.2.7.1. Quality of Service (QoS) ..................20
3.2.7.2. Resiliency ................................21
3.2.8. Management .........................................22
3.3. VPWS ......................................................22
3.3.1. Provisioning and Auto-Discovery ....................23
3.3.1.1. Attachment Circuit Provisioning ...........23
3.3.1.2. PW Provisioning for Arbitrary
Overlay Topologies ........................23
3.3.1.3. Colored Pools PW Provisioning Model .......25
3.3.2. Requirements on Auto-Discovery Procedures ..........27
3.3.3. Heterogeneous Pseudowires ..........................28
3.4. VPLS Emulated LANs ........................................29
3.4.1. VPLS Overlay Topologies and Forwarding .............31
3.4.2. Provisioning and Auto-Discovery ....................33
3.4.3. Distributed PE .....................................33
3.4.4. Scaling Issues in VPLS Deployment ..................36
3.5. IP-Only LAN-Like Service (IPLS) ...........................36
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RFC 4664 Framework for Layer 2 VPNs September 2006
4. Security Considerations ........................................37
4.1. Provider Network Security Issues ..........................37
4.2. Provider-Customer Network Security Issues .................39
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