datatracker.ietf.org
Sign in
Version 5.6.4.p1, 2014-10-20
Report a bug

QoS Routing Mechanisms and OSPF Extensions
RFC 2676

Document type: RFC - Experimental (August 1999; Errata)
Document stream: IETF
Last updated: 2013-03-02
Other versions: plain text, pdf, html

IETF State: (None)
Document shepherd: No shepherd assigned

IESG State: RFC 2676 (Experimental)
Responsible AD: (None)
Send notices to: No addresses provided

Network Working Group                                  G. Apostolopoulos
Request for Comments: 2676                                   D. Williams
Category: Experimental                                               IBM
                                                                S. Kamat
                                                                  Lucent
                                                               R. Guerin
                                                                   UPenn
                                                                 A. Orda
                                                                Technion
                                                           T. Przygienda
                                                           Siara Systems
                                                             August 1999

               QoS Routing Mechanisms and OSPF Extensions

Status of this Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

Abstract

   This memo describes extensions to the OSPF [Moy98] protocol to
   support QoS routes.  The focus of this document is on the algorithms
   used to compute QoS routes and on the necessary modifications to OSPF
   to support this function, e.g., the information needed, its format,
   how it is distributed, and how it is used by the QoS path selection
   process.  Aspects related to how QoS routes are established and
   managed are also briefly discussed.  The goal of this document is to
   identify a framework and possible approaches to allow deployment of
   QoS routing capabilities with the minimum possible impact to the
   existing routing infrastructure.

   In addition, experience from an implementation of the proposed
   extensions in the GateD environment [Con], along with performance
   measurements is presented.

Apostolopoulos, et al.        Experimental                      [Page 1]
RFC 2676       QoS Routing Mechanisms and OSPF Extensions    August 1999

Table of Contents

   1. Introduction                                                    3
       1.1. Overall Framework . . . . . . . . . . . . . . . . . . . . 3
       1.2. Simplifying Assumptions . . . . . . . . . . . . . . . . . 5
   2. Path Selection Information and Algorithms                       7
       2.1. Metrics . . . . . . . . . . . . . . . . . . . . . . . . . 7
       2.2. Advertisement of Link State Information . . . . . . . . . 8
       2.3. Path Selection  . . . . . . . . . . . . . . . . . . . . .10
             2.3.1. Path Computation Algorithm  . . . . . . . . . . .11
   3. OSPF Protocol Extensions                                       16
       3.1. QoS -- Optional Capabilities  . . . . . . . . . . . . . .17
       3.2. Encoding Resources as Extended TOS  . . . . . . . . . . .17
             3.2.1. Encoding bandwidth resource . . . . . . . . . . .19
             3.2.2. Encoding Delay  . . . . . . . . . . . . . . . . .21
       3.3. Packet Formats  . . . . . . . . . . . . . . . . . . . . .21
       3.4. Calculating the Inter-area Routes . . . . . . . . . . . .22
       3.5. Open Issues . . . . . . . . . . . . . . . . . . . . . . .22
   4. A Reference Implementation based on GateD                      22
       4.1. The Gate Daemon (GateD) Program . . . . . . . . . . . . .22
       4.2. Implementing the QoS Extensions of OSPF . . . . . . . . .23
             4.2.1. Design Objectives and Scope . . . . . . . . . . .23
             4.2.2. Architecture  . . . . . . . . . . . . . . . . . .24
       4.3. Major Implementation Issues . . . . . . . . . . . . . . .25
       4.4. Bandwidth and Processing Overhead of QoS Routing  . . . .29
   5. Security Considerations                                        32
   A. Pseudocode for the BF Based Pre-Computation Algorithm          33
   B. On-Demand Dijkstra Algorithm for QoS Path Computation          36
   C. Precomputation Using Dijkstra Algorithm                        39
   D. Explicit Routing Support                                       43
   Endnotes                                                          45
   References                                                        46
   Authors' Addresses                                                48
   Full Copyright Statement                                          50

Apostolopoulos, et al.        Experimental                      [Page 2]
RFC 2676       QoS Routing Mechanisms and OSPF Extensions    August 1999

1. Introduction

   In this document, we describe a set of proposed additions to the OSPF

[include full document text]