Terminology for Forwarding Information Base (FIB) based Router Performance
RFC 3222

Network Working Group                                         G. Trotter
Request for Comments: 3222                          Agilent Technologies
Category: Informational                                    December 2001

    Terminology for Forwarding Information Base (FIB) based Router
                              Performance

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 (2001).  All Rights Reserved.

Abstract

   This document describes the terms to be used in a methodology that
   determines the IP packet forwarding performance of IP routers as a
   function of the forwarding information base installed within a
   router.  The forwarding performance of an IP router may be dependent
   upon or may be linked to the composition and size of the forwarding
   information base installed within a router.

Trotter                      Informational                      [Page 1]
RFC 3222              FIB based Router Performance         December 2001

Table of Contents

   1. Introduction.................................................... 2
   2. Overview........................................................ 3
   3. Existing Definitions............................................ 3
   4. Definition Format............................................... 3
   5. Definitions - parameters........................................ 4
   5.1 Network Prefix................................................. 4
   5.2 Network Prefix Length.......................................... 4
   5.3 Forwarding Information Base (FIB).............................. 5
   5.4 Forwarding Information Base Entry.............................. 6
   5.5 Forwarding Information Base Size............................... 6
   5.6 Longest Length Prefix Match Algorithm.......................... 7
   5.7 Forwarding Information Base Prefix Distribution................ 7
   5.8 Per-Interface or Per-Card Forwarding Information Base.......... 8
   5.9 Per-Interface Forwarding Information Base Cache................ 9
   5.10 Route Aggregation............................................ 10
   6. Definitions - metrics.......................................... 10
   6.1 Maximum Forwarding Information Base Size...................... 11
   6.2 Forwarding Information Base Learning Time..................... 11
   6.3 Forwarding Information Base-dependent Throughput.............. 12
   6.4 Forwarding Information Base-dependent Latency................. 12
   6.5 Forwarding Information Base-dependent Frame Loss Rate......... 13
   7. Security Considerations........................................ 13
   8. References..................................................... 13
   9. Author's Address............................................... 14
   10. Full Copyright Statement...................................... 15

1. Introduction

   This document defines terms that are to be used in a methodology that
   determines the IP packet forwarding performance of IP routers as a
   function of the forwarding information base installed within the
   router.

   The objective of this methodology is to evaluate the performance
   levels of IP routers as forwarding information bases continue to grow
   in size and complexity of structure.

   This methodology utilizes the packet forwarding performance
   measurements described in [2]; reference will also be made to the
   associated terminology document [3] for these terms.

Trotter                      Informational                      [Page 2]
RFC 3222              FIB based Router Performance         December 2001

2. Overview

   In order to measure the forwarding information base-based router
   performance, different forwarding information bases (5.3) are
   installed in the router.  The two key elements describing the FIB are
   the FIB size (5.5) and FIB prefix distribution (5.7).  The forwarding
   performance of a router may be dependent upon these two primary
   factors, particularly if FIB prefix distributions tend towards longer
   network prefixes (5.1).  The FIB-dependent throughput, latency and
   frame loss rate (6.3, 6.4, 6.5), measured with fully meshed traffic
   flows [2], will reflect the change in performance of the router.
   Tests may need to be performed up to the maximum FIB size (6.1).

   When configuring the router for these measurements, the routes need
   to be manually entered into the router, or advertised via a routing
   protocol.  It may take some period of time (the FIB learning time
   (6.2)) before the router learns all the routes.

   When routes are advertised into the router, the routes should be