【正文】 ted in a single direction between mutually exclusive sets of source and destination interfaces of a DUT/SUT. Such traffic, however, can be distributed between interfaces in different ways.When traffic is sent to two or more interfaces from an external 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 manytoone. Traffic can also be sent to a single input interface and forwarded by the DUT/SUT to two or more output interfaces to achieve a onetomany distribution of traffic. Such traffic distributions can also be bined 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. It should be noted that measurement of the minimum interframe gap serves to detect violations of the IEEE standard.Issues: half duplex / full duplexMeasurement units: n/aSee Also: bidirectional traffic () nonmeshed traffic () partially meshed traffic () fully meshed traffic () congestion control ()北京國信網(wǎng)安信息系統(tǒng)測評技術(shù)試驗室Beijing GuoXinWangAn Information Technology Testingamp。T_2022_004國信網(wǎng)安測評技術(shù)體系之測試方法篇（測試文檔）RFC2285 Benchmarking Terminology for LAN Switching Devices，北京國信網(wǎng)安信息系統(tǒng)測評技術(shù)實驗室北京國信網(wǎng)安信息系統(tǒng)測評技術(shù)試驗室Beijing GuoXinWangAn Information Technology Testingamp。Evaluation LaboratoryBenchmarking Terminology for LAN Switching Devices 第 2 頁 共 20 頁Benchmarking Terminology for LAN Switching Devices RFC 2285，Network Working Group R. MandevilleRequest for Comments: 2285 European Network LaboratoriesCategory: Informational February 1998 Status of this MemoThis memo provides information for the Inter munity. It does not specify an Inter standard of any kind. Distribution of this memo is unlimited.Copyright Notice Copyright (C) The Inter Society (1998). All Rights Reserved.table of Contents1 Introduction This document is intended to provide terminology for the benchmarking of local area work (LAN) switching devices. It extends the terminology already defined for benchmarking work interconnect devices in RFCs 1242 and 1944 to switching devices. Although it might be found useful to apply some of the terms defined here to a broader range of work interconnect devices, this RFC 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 Devicescontains discussions of a number of terms relevant to the benchmarking of switching devices and should also be consulted.For the sake of clarity and continuity this RFC adopts the template for definitions set out in Section 2 of RFC 1242. Definitions are indexed and grouped together in sections for ease of reference. The key words MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL in this ocument are to be interpreted as described in RFC 2119.3 Term definitions Devices This group of definitions applies to all types of working devices.北京國信網(wǎng)安信息系統(tǒng)測評技術(shù)試驗室Beijing GuoXinWangAn Information Technology Testingamp。Evaluation LaboratoryBenchmarking Terminology for LAN Switching Devices 第 5 頁 共 20 頁 head of line blocking () Bidirectional trafficDefinition: 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. When a tester offers bidirectional traffic to a DUT/SUT all the interfaces which receive frames from the tester also transmit frames back to the tester. Bidirectional traffic MUST be offered when measuring the throughput or forwarding rate of full duplex interfaces of a switching device.Issues:truncated binary exponential backoff algorithmMeasurement units: n/a See Also: unidirectional traffic () nonmeshed traffic () partially meshed traffic ()fully meshed traffic () Traffic distribution This group of definitions applies to the distribution of frames forwarded by a DUT/SUT. Nonmeshed trafficDefinition:Frames offered to a single input interface and addressed to a single output interface of a DUT/SUT where input and output interfaces are grouped in mutually exclusive pairs.Discussion: In the simplest instance of nonmeshed traffic all frames are offered to a single input interface and addressed to a single output interface. The onetoone mapping of input to output interfaces required by nonmeshed traffic can be extended to multiple mutually exclusive pairs of input and output interfaces. Measurement units:n/aIssues:half duplex / full duplex北京國信網(wǎng)安信息系統(tǒng)測評技術(shù)試驗室Beijing GuoXinWangAn Information Technology Testingamp。Evaluation LaboratoryBenchmarking Terminology for LAN Switching Devices 第 9 頁 共 20 頁 Interburst gap (IBG)Definition:The interval between two bursts.Discussion:This definition conforms to the discussion in section 20 of RFC1944 on bursty traffic. Bidirectional and meshed traffic are inherently bursty since interfaces share their time between receiving and transmitting frames. External sources offering bursty traffic for a given frame s