交换机测试规范3 RFC2285

Network Working Group R. Mandeville

Request for Comments: 2285 European Network Laboratories

Category: Informational February 1998

Benchmarking Terminology for LAN Switching Devices

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

3.1.1 Device under test (DUT) . . . . . . . . . . . . . . . . 3

3.1.2 System under test (SUT) . . . . . . . . . . . . . . . . 3

3.2 Traffic orientation. . . . . . . . . . . . . . . . . . . . . 4

3.2.1 Unidirectional traffic. . . . . . . . . . . . . . . . . 4

3.2.2 Bidirectional traffic . . . . . . . . . . . . . . . . . 5

3.3 Traffic distribution . . . . . . . . . . . . . . . . . . . . 6

3.3.1 Non-meshed traffic. . . . . . . . . . . . . . . . . . . 6

3.3.2 Partially meshed traffic. . . . . . . . . . . . . . . . 7

3.3.3 Fully meshed traffic. . . . . . . . . . . . . . . . . . 8

3.4 Bursts . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.5.3 Maximum offered load (MOL) . . . . . . . . . . . . . . 13

3.5.4 Overloading . . . . . . . . . . . . . . . . . . . . . 14

3.6 Forwarding rates . . . . . . . . . . . . . . . . . . . . . 15

3.6.1 Forwarding rate (FR) . . . . . . . . . . . . . . . . . 15

3.6.2 Forwarding rate at maximum offered load (FRMOL). . . . 16

3.6.3 Maximum forwarding rate (MFR). . . . . . . . . . . . . 16

3.7 Congestion control . . . . . . . . . . . . . . . . . . . . 17

3.7.1 Backpressure . . . . . . . . . . . . . . . . . . . . . 17

3.7.2 Forward pressure . . . . . . . . . . . . . . . . . . . 18

Mandeville Informational [Page 1]

3.8.1 Address caching capacity . . . . . . . . . . . . . . . 20

3.8.2 Address learning rate . . . . . . . . . . . . . . . . 20

3.8.3 Flood count . . . . . . . . . . . . . . . . . . . . . 21

3.10 Broadcasts . . . . . . . . . . . . . . . . . . . . . . . . 22

3.10.2 Broadcast latency . . . . . . . . . . . . . . . . . . 23

4. Security Considerations . . . . . . . . . . . . . . . . . . . . 24

5. References. . . . . . . . . . . . . . . . . . . . . . . . . . . 24

6. Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . . 24

7. Author’s Address. . . . . . . . . . . . . . . . . . . . . . . . 24

8. Full Copyright Statement. . . . . . . . . . . . . . . . . . . . 25

1. Introduction

This document is intended to provide terminology for the benchmarking

terminology already defined for benchmarking network interconnect

primarily deals with devices which switch frames at the Medium Access

Control (MAC) layer. It defines terms in relation to the traffic put

to use when benchmarking switching devices, forwarding performance,

congestion control, latency, address handling and filtering.

2. Existing definitions

RFC 1242 "Benchmarking Terminology for Network Interconnect Devices"

should be consulted before attempting to make use of this document.

RFC 1944 "Benchmarking Methodology for Network Interconnect Devices"

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this

document are to be interpreted as described in RFC 2119.

Mandeville Informational [Page 2]

3.1 Devices

This group of definitions applies to all types of networking devices.

The network forwarding device to which stimulus is offered and

response measured.

Discussion:

A single stand-alone or modular unit which receives frames on one

or more of its interfaces and then forwards them to one or more

the frame.

Measurement units:

See Also:

system under test (SUT) (3.1.2)

3.1.2 System Under Test (SUT)

Definition:

The collective set of network devices to which stimulus is offered

making process, such as routers or switches; other devices may be

passive such as a CSU/DSU. Regardless of constituent components,

the system is treated as a singular entity to which stimulus is

offered and response measured.

Mandeville Informational [Page 3]

n/a

Issues:

3.2 Traffic orientation

This group of definitions applies to the traffic presented to the

interfaces of a DUT/SUT and indicates whether the interfaces are

receiving only, transmitting only, or both receiving and

transmitting.

Discussion:

This definition conforms to the discussion in section 16 of RFC

1944 which describes how unidirectional traffic can be offered to

a DUT/SUT to measure throughput. Unidirectional traffic is also

appropriate for:

-the measurement of the minimum inter-frame gap -the creation of

many-to-one or one-to-many interface overload -the detection of

head of line blocking -the measurement of forwarding rates and

which do not themselves receive any frames.

It is useful to distinguish traffic orientation and traffic

distribution when considering traffic patterns used in device

testing. Unidirectional traffic, for example, is traffic

orientated in a single direction between mutually exclusive sets

of source and destination interfaces of a DUT/SUT. Such traffic,

Mandeville Informational [Page 4]

source and then forwarded by the DUT/SUT to a single output

interface the traffic orientation is unidirectional and the

traffic distribution between interfaces is many-to-one. Traffic

distribution of traffic.

Such traffic distributions can also be combined to test for head

of line blocking or to measure forwarding rates and throughput

when congestion control mechanisms are active.

When a DUT/SUT is equipped with interfaces running at different

media rates the number of input interfaces required to load or

overload an output interface or interfaces will vary.

serves to detect violations of the IEEE 802.3 standard.

Issues:

n/a

See Also:

bidirectional traffic (3.2.2)

non-meshed traffic (3.3.1)

partially meshed traffic (3.3.2)

fully meshed traffic (3.3.3)

congestion control (3.7)

Frames presented to a DUT/SUT such that every receiving interface

also transmits.

Discussion:

This definition conforms to the discussion in section 14 of RFC

1944.

Mandeville Informational [Page 5]