RFC 3386 (rfc3386) - Page 2 of 27

Network Hierarchy and Multilayer Survivability

RFC 3386          Hierarchy & Multilayer Survivability     November 2002


Table of Contents

   1. Introduction..............................................2
   2. Terminology and Concepts..................................5
   2.1 Hierarchy................................................6
   2.1.1 Vertical Hierarchy.....................................5
   2.1.2 Horizontal Hierarchy...................................6
   2.2 Survivability Terminology................................6
   2.2.1 Survivability..........................................7
   2.2.2 Generic Operations.....................................7
   2.2.3 Survivability Techniques...............................8
   2.2.4 Survivability Performance..............................9
   2.3 Survivability Mechanisms: Comparison....................10
   3. Survivability............................................11
   3.1 Scope...................................................11
   3.2 Required initial set of survivability mechanisms........12
   3.2.1 1:1 Path Protection with Pre-Established Capacity.....12
   3.2.2 1:1 Path Protection with Pre-Planned Capacity.........13
   3.2.3 Local Restoration.....................................13
   3.2.4 Path Restoration......................................14
   3.3 Applications Supported..................................14
   3.4 Timing Bounds for Survivability Mechanisms..............15
   3.5 Coordination Among Layers...............................16
   3.6 Evolution Toward IP Over Optical........................17
   4. Hierarchy Requirements...................................17
   4.1 Historical Context......................................17
   4.2 Applications for Horizontal Hierarchy...................18
   4.3 Horizontal Hierarchy Requirements.......................19
   5. Survivability and Hierarchy..............................19
   6. Security Considerations..................................20
   7. References...............................................21
   8. Acknowledgments..........................................22
   9. Contributing Authors.....................................22
   Appendix A: Questions used to help develop requirements.....23
   Editors' Addresses..........................................26
   Full Copyright Statement....................................27

1. Introduction

   This document is the result of the Network Hierarchy and
   Survivability Techniques Design Team established within the Traffic
   Engineering Working Group.  This team collected and documented
   current and near term requirements for survivability and hierarchy in
   service provider environments.  For clarity, an expanded set of
   definitions is included.  The team determined that there appears to
   be a need to define a small set of interoperable survivability
   approaches in packet and non-packet networks.  Suggested approaches
   include path-based as well as one that repairs connections in



Lai, et. al.                 Informational