MPLS Forwarding Compliance and Performance Requirements
RFC 7325
Internet Engineering Task Force (IETF) C. Villamizar, Ed.
Request for Comments: 7325 OCCNC
Category: Informational K. Kompella
ISSN: 2070-1721 Juniper Networks
S. Amante
Apple Inc.
A. Malis
Huawei
C. Pignataro
Cisco
August 2014
MPLS Forwarding Compliance and Performance Requirements
Abstract
This document provides guidelines for implementers regarding MPLS
forwarding and a basis for evaluations of forwarding implementations.
Guidelines cover many aspects of MPLS forwarding. Topics are
highlighted where implementers might otherwise overlook practical
requirements that are unstated or underemphasized, or that are
optional for conformance to RFCs but often considered mandatory by
providers.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7325.
Villamizar, et al. Informational [Page 1]
RFC 7325 MPLS Forwarding August 2014
Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction and Document Scope . . . . . . . . . . . . . . . 4
1.1. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Use of Requirements Language . . . . . . . . . . . . . . 8
1.3. Apparent Misconceptions . . . . . . . . . . . . . . . . . 9
1.4. Target Audience . . . . . . . . . . . . . . . . . . . . . 10
2. Forwarding Issues . . . . . . . . . . . . . . . . . . . . . . 11
2.1. Forwarding Basics . . . . . . . . . . . . . . . . . . . . 11
2.1.1. MPLS Special-Purpose Labels . . . . . . . . . . . . . 12
2.1.2. MPLS Differentiated Services . . . . . . . . . . . . 13
2.1.3. Time Synchronization . . . . . . . . . . . . . . . . 14
2.1.4. Uses of Multiple Label Stack Entries . . . . . . . . 14
2.1.5. MPLS Link Bundling . . . . . . . . . . . . . . . . . 15
2.1.6. MPLS Hierarchy . . . . . . . . . . . . . . . . . . . 16
2.1.7. MPLS Fast Reroute (FRR) . . . . . . . . . . . . . . . 16
2.1.8. Pseudowire Encapsulation . . . . . . . . . . . . . . 17
2.1.8.1. Pseudowire Sequence Number . . . . . . . . . . . 17
2.1.9. Layer 2 and Layer 3 VPN . . . . . . . . . . . . . . . 19
2.2. MPLS Multicast . . . . . . . . . . . . . . . . . . . . . 20
2.3. Packet Rates . . . . . . . . . . . . . . . . . . . . . . 21
2.4. MPLS Multipath Techniques . . . . . . . . . . . . . . . . 23
2.4.1. Pseudowire Control Word . . . . . . . . . . . . . . . 24
2.4.2. Large Microflows . . . . . . . . . . . . . . . . . . 24
2.4.3. Pseudowire Flow Label . . . . . . . . . . . . . . . . 25
2.4.4. MPLS Entropy Label . . . . . . . . . . . . . . . . . 25
2.4.5. Fields Used for Multipath Load Balance . . . . . . . 25
2.4.5.1. MPLS Fields in Multipath . . . . . . . . . . . . 26
2.4.5.2. IP Fields in Multipath . . . . . . . . . . . . . 27
2.4.5.3. Fields Used in Flow Label . . . . . . . . . . . . 29
2.4.5.4. Fields Used in Entropy Label . . . . . . . . . . 29
2.5. MPLS-TP and UHP . . . . . . . . . . . . . . . . . . . . . 30
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