An Analysis of Scaling Issues in MPLS-TE Core Networks
RFC 5439
Document | Type | RFC - Informational (February 2009; Errata) | |
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Authors | Adrian Farrel , Olufemi Komolafe , Seisho Yasukawa | ||
Last updated | 2020-01-21 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Reviews | |||
Stream | WG state | WG Document | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5439 (Informational) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Ross Callon | ||
IESG note | RC 5439 | ||
Send notices to | (None) |
Network Working Group S. Yasukawa Request for Comments: 5439 NTT Category: Informational A. Farrel Old Dog Consulting O. Komolafe Cisco Systems February 2009 An Analysis of Scaling Issues in MPLS-TE Core Networks 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) 2009 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 Provisions Relating to IETF Documents (http://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract Traffic engineered Multiprotocol Label Switching (MPLS-TE) is deployed in providers' core networks. As providers plan to grow these networks, they need to understand whether existing protocols and implementations can support the network sizes that they are planning. This document presents an analysis of some of the scaling concerns for the number of Label Switching Paths (LSPs) in MPLS-TE core networks, and examines the value of two techniques (LSP hierarchies and multipoint-to-point LSPs) for improving scaling. The intention is to motivate the development of appropriate deployment techniques and protocol extensions to enable the application of MPLS-TE in large networks. This document only considers the question of achieving scalability for the support of point-to-point MPLS-TE LSPs. Point-to-multipoint MPLS-TE LSPs are for future study. Yasukawa, et al. Informational [Page 1] RFC 5439 Scaling in MPLS-TE February 2009 Table of Contents 1. Introduction ....................................................3 1.1. Overview ...................................................3 1.2. Glossary of Notation .......................................5 2. Issues of Concern for Scaling ...................................5 2.1. LSP State ..................................................5 2.2. Processing Overhead ........................................6 2.3. RSVP-TE Implications .......................................6 2.4. Management .................................................7 3. Network Topologies ..............................................8 3.1. The Snowflake Network Topology .............................9 3.2. The Ladder Network Topology ...............................11 3.3. Commercial Drivers for Selected Configurations ............14 3.4. Other Network Topologies ..................................15 4. Required Network Sizes .........................................16 4.1. Practical Numbers .........................................16 5. Scaling in Flat Networks .......................................16 5.1. Snowflake Networks ........................................17 5.2. Ladder Networks ...........................................18 6. Scaling Snowflake Networks with Forwarding Adjacencies .........22 6.1. Two-Layer Hierarchy .......................................22 6.1.1. Tuning the Network Topology to Suit the Two-Layer Hierarchy ................................23 6.2. Alternative Two-Layer Hierarchy ...........................24 6.3. Three-Layer Hierarchy .....................................25 6.4. Issues with Hierarchical LSPs .............................26 7. Scaling Ladder Networks with Forwarding Adjacencies ............27 7.1. Two-Layer Hierarchy .......................................27 7.2. Three-Layer Hierarchy .....................................28 7.3. Issues with Hierarchical LSPs .............................29 8. Scaling Improvements through Multipoint-to-Point LSPs ..........30 8.1. Overview of MP2P LSPs .....................................30 8.2. LSP State: A Better Measure of Scalability ................31 8.3. Scaling Improvements for Snowflake Networks ...............32 8.3.1. Comparison with Other Scenarios ....................33 8.4. Scaling Improvements for Ladder Networks ..................34 8.4.1. Comparison with Other Scenarios ....................36 8.4.2. LSP State Compared with LSP Numbers ................37 8.5. Issues with MP2P LSPs .....................................37Show full document text