Terminology for IP Multicast Benchmarking
RFC 2432

Network Working Group                                          K. Dubray
Request for Comments: 2432                           IronBridge Networks
Category: Informational                                     October 1998

               Terminology for IP Multicast Benchmarking

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 (1998).  All Rights Reserved.

Abstract

   The purpose of this document is to define terminology specific to the
   benchmarking of multicast IP forwarding devices. It builds upon the
   tenets set forth in RFC 1242, RFC 2285, and other IETF Benchmarking
   Methodology Working Group (BMWG) efforts.  This document seeks to
   extend these efforts to the multicast paradigm.

   The BMWG produces two major classes of documents: Benchmarking
   Terminology documents and Benchmarking Methodology documents. The
   Terminology documents present the benchmarks and other related terms.
   The Methodology documents define the procedures required to collect
   the benchmarks cited in the corresponding Terminology documents.

1.  Introduction

   Network forwarding devices are being required to take a single frame
   and support delivery to a number of destinations having membership to
   a particular group. As such, multicast support may place a different
   burden on the resources of these network forwarding devices than with
   unicast or broadcast traffic types.

   Such burdens may not be readily apparent at first glance - the IP
   multicast packet's Class D address may be the only noticeable
   difference from an IP unicast packet.  However, there are many
   factors that may impact the treatment of IP multicast packets.

   Consider how a device's architecture may impact the handling of a
   multicast frame.  For example, is the multicast packet subject to the
   same processing as its unicast analog?  Or is the multicast packet
   treated as an exeception and processed on a different data path?

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RFC 2432       Terminology for IP Multicast Benchmarking    October 1998

   Consider, too, how a shared memory architecture may demonstrate a
   different performance profile than an architecture which explicitly
   passes each individual packet between the processing entities.

   In addition to forwarding device architecture, there are other
   factors that may impact a device's or system's multicast related
   performance.  Protocol requirements may demand that routers and
   switches consider destination and source addressing in its multicast
   forwarding decisions.  Capturing multicast source/destination
   addressing information may impact forwarding table size and lengthen
   lookups.  Topological factors such as the degree of packet
   replication, the number of multicast groups being supported by the
   system, or the placement of multicast packets in unicast wrappers to
   span non-multicast network paths may all potentially affect a
   system's multicast related performance. For an overall understanding
   of IP multicasting, the reader is directed to [Se98], [Hu95], and
   [Mt98].

   By clearly identifying IP multicast benchmarks and related
   terminology in this document, it is hoped that detailed methodologies
   can be generated in subsequent documents.  Taken in tandem, these two
   efforts endeavor to assist the clinical, empirical, and consistent
   characterization of certain aspects of multicast technologies and
   their individual implementations.  Understanding the operational
   profile of multicast forwarding devices may assist the network
   designer to better deploy multicast in his or her networking
   environment.

   Moreover, this document focuses on one source to many destinations
   profiling.  Elements of this document may require extension when
   considering multiple source to multiple destination IP multicast
   communication.

2.  Definition Format

   This section cites the template suggested by RFC 1242 in the
   specification of a term to be defined.

   Term to be defined.

   Definition:
      The specific definition for the term.

   Discussion:
      A brief discussion of the term, its application, or other
      information that would build understanding.

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RFC 2432       Terminology for IP Multicast Benchmarking    October 1998

   Measurement units:
      Units used to record measurements of this term, if applicable.

   [Issues:]
      List of issues or conditions that affect this term. This field can