分享
 
 
 

RFC4062 - OSPF Benchmarking Terminology and Concepts

王朝other·作者佚名  2008-05-31
窄屏简体版  字體: |||超大  

Network Working Group V. Manral

Request for Comments: 4062 SiNett Corp.

Category: Informational R. White

Cisco Systems

A. Shaikh

AT&T Labs (Research)

April 2005

OSPF Benchmarking Terminology and Concepts

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 (2005).

Abstract

This document eXPlains the terminology and concepts used in OSPF

benchmarking. Although some of these terms may be defined elsewhere

(and we will refer the reader to those definitions in some cases) we

include discussions concerning these terms, as they relate

specifically to the tasks involved in benchmarking the OSPF protocol.

1. IntrodUCtion

This document is a companion to [BENCHMARK], which describes basic

Open Shortest Path First [OSPF] testing methods. This document

explains terminology and concepts used in OSPF Testing Framework

Documents, such as [BENCHMARK].

2. Specification of Requirements

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 [RFC2119].

[RFC2119] key words in this document are used to ensure

methodological control, which is very important in the specification

of benchmarks. This document does not specify a network-related

protocol.

3. Common Definitions

Definitions in this section are well-known industry and benchmarking

terms that may be defined elsewhere.

o White Box (Internal) Measurements

- Definition

White box measurements are those reported and collected on

the Device Under Test (DUT) itself.

- Discussion

These measurements rely on output and event recording,

along with the clocking and time stamping available on the

DUT itself. Taking measurements on the DUT may impact the

actual outcome of the test, since it can increase processor

loading, memory utilization, and timing factors. Some

devices may not have the required output readily available

for taking internal measurements.

Note: White box measurements can be influenced by the

vendor's implementation of various timers and processing

models. Whenever possible, internal measurements should be

compared to external measurements to verify and validate

them.

Because of the potential for variations in collection and

presentation methods across different DUTs, white box

measurements MUST NOT be used as a basis for comparison in

benchmarks. This has been a guiding principle of the

Benchmarking Methodology Working Group.

o Black Box (External) Measurements

- Definition

Black box measurements infer the performance of the DUT

through observation of its communications with other

devices.

- Discussion

One example of a black box measurement is when a downstream

device receives complete routing information from the DUT,

it can be inferred that the DUT has transmitted all the

routing information available. External measurements of

internal operations may suffer in that they include not

just the protocol action times, but also propagation

delays, queuing delays, and other such factors.

For the purposes of [BENCHMARK], external techniques are

more readily applicable.

o Multi-device Measurements

- Measurements assessing communications (usually in

combination with internal operations) between two or more

DUTs. Multi-device measurements may be internal or

external.

4. Terms Defined Elsewhere

Terms in this section are defined elsewhere and are included only as

they apply to [BENCHMARK].

o Point-to-Point Links

- Definition

See [OSPF], Section 1.2.

- Discussion

A point-to-point link can take less time to converge than a

broadcast link of the same speed because it does not have

the overhead of DR election. Point-to-point links can be

either numbered or unnumbered. However, in the context of

[BENCHMARK] and [OSPF], the two can be regarded as the

same.

o Broadcast Link

- Definition

See [OSPF], Section 1.2.

- Discussion

The adjacency formation time on a broadcast link can be

greater than that on a point-to-point link of the same

speed because DR election has to take place. All routers

on a broadcast network form adjacency with the DR and BDR.

Manral, et al. Informational [Page 3]

RFC 4062 OSPF Benchmarking Terminology April 2005

Asynchronous flooding also takes place through the DR. In

the context of convergence, it may take more time for an

LSA to be flooded from one DR-other router to another

because the LSA first has to be processed at the DR.

o Shortest Path First Execution Time

- Definition

The time taken by a router to complete the SPF process, as

described in [OSPF].

- Discussion

This does not include the time taken by the router to

install routes in the forwarding engine.

Some implementations may force two intervals, the SPF hold

time and the SPF delay, between successive SPF

calculations. If an SPF hold time exists, it should be

suBTracted from the total SPF execution time. If an SPF

delay exists, it should be noted in the test results.

- Measurement Units

The SPF time is generally measured in milliseconds.

o Hello Interval

- Definition

See [OSPF], Section 7.1.

- Discussion

The hello interval must be the same for all routers on a

network.

Decreasing the hello interval can allow the router dead

interval (below) to be reduced, thus reducing convergence

times in those situations where the router dead interval's

timing out causes an OSPF process to notice an adjacency

failure. Further discussion of small hello intervals is

given in [OSPF-SCALING].

o Router Dead Interval

- Definition

See [OSPF], Section 7.1.

- Discussion

This is advertised in the router's Hello Packets in the

Router-DeadInterval field. The router dead interval should

be some multiple of the HelloInterval (perhaps 4 times the

hello interval) and must be the same for all routers

attached to a common network.

5. Concepts

5.1. The Meaning of Single Router Control Plane Convergence

A network is termed as converged when all the devices within the

network have a loop-free path to each possible destination. However,

because we are not testing network convergence but testing

performance for a particular device within a network, this definition

needs to be streamlined to fit within a single device view.

In this case, convergence will mean the point in time when the DUT

has performed all actions needed in order to react to the change in

the topology represented by the test condition. For instance, an

OSPF device must flood any new information it has received, rebuild

its shortest path first (SPF) tree, and install any new paths or

destinations in the local routing information base (RIB, or routing

table).

Note that the word "convergence" has two distinct meanings: the

process of a group of individuals meeting at the same place, and the

process of an individual coming to the same place as an existing

group. This work focuses on the second meaning of the word, so we

consider the time required for a single device to adapt to a network

change to be Single Router Convergence.

This concept does not include the time required for the control plane

of the device to transfer the information required to forward packets

to the data plane. It also does not include the amount of time

between when the data plane receives that information and when it is

able to forward traffic.

5.2. Measuring Convergence

Obviously, there are several elements to convergence, even under the

definition given above for a single device, including (but not

limited to) the following:

o The time it takes for the DUT to pass the information about a

network event on to its neighbors.

o The time it takes for the DUT to process information about a

network event and to calculate a new Shortest Path Tree (SPT).

o The time it takes for the DUT to make changes in its local RIB

reflecting the new shortest path tree.

5.3. Types of Network Events

A network event is an event that causes a change in the network

topology.

o Link or Neighbor Device Up

The time needed for an OSPF implementation to recognize a new

link coming up on the device, to build any necessary

adjacencies, to synchronize its database, and to perform all

other actions necessary to converge.

o Initialization

The time needed for an OSPF implementation to be initialized, to

recognize any links across which OSPF must run, to build any

needed adjacencies, to synchronize its database, and to perform

other actions necessary to converge.

o Adjacency Down

The time needed for an OSPF implementation to recognize a link

down/adjacency loss based on hello timers alone, to propagate

any information as necessary to its remaining adjacencies, and

to perform other actions necessary to converge.

o Link Down

The time needed for an OSPF implementation to recognize a link

down based on layer 2-provided information, to propagate any

information as needed to its remaining adjacencies, and to

perform other actions necessary to converge.

6. Security Considerations

This document does not modify the underlying security considerations

in [OSPF].

7. Acknowledgements

The authors would like to thank Howard Berkowitz (hcb@clark.net),

Kevin Dubray (kdubray@juniper.net), Scott Poretsky

(sporetsky@avici.com), and Randy Bush (randy@psg.com) for their

discussion, ideas, and support.

8. Normative References

[BENCHMARK] Manral, V., White, R., and A. Shaikh, "Benchmarking

Basic OSPF Single Router Control Plane Convergence",

RFC 4061, April 2005.

[OSPF] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April

1998.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate

Requirement Levels", BCP 14, RFC 2119, March 1997.

9. Informative References

[OSPF-SCALING] Choudhury, Gagan L., Editor, "Prioritized Treatment of

Specific OSPF Packets and Congestion Avoidance", Work

in Progress, August 2003.

Authors' Addresses

Vishwas Manral,

SiNett Corp,

Ground Floor,

Embassy Icon Annexe,

2/1, Infantry Road,

Bangalore, India

EMail: vishwas@sinett.com

Russ White

Cisco Systems, Inc.

7025 Kit Creek Rd.

Research Triangle Park, NC 27709

EMail: riw@cisco.com

Aman Shaikh

AT&T Labs (Research)

180 Park Av, PO Box 971

Florham Park, NJ 07932

EMail: ashaikh@research.att.com

Full Copyright Statement

Copyright (C) The Internet Society (2005).

This document is subject to the rights, licenses and restrictions

contained in BCP 78, and except as set forth therein, the authors

retain all their rights.

This document and the information contained herein are provided on an

"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS

OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET

ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,

INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE

INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED

WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

The IETF takes no position regarding the validity or scope of any

Intellectual Property Rights or other rights that might be claimed to

pertain to the implementation or use of the technology described in

this document or the extent to which any license under such rights

might or might not be available; nor does it represent that it has

made any independent effort to identify any such rights. Information

on the procedures with respect to rights in RFC documents can be

found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat and any

assurances of licenses to be made available, or the result of an

attempt made to obtain a general license or permission for the use of

such proprietary rights by implementers or users of this

specification can be obtained from the IETF on-line IPR repository at

http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any

copyrights, patents or patent applications, or other proprietary

rights that may cover technology that may be required to implement

this standard. Please address the information to the IETF at ietf-

ipr@ietf.org.

Acknowledgement

Funding for the RFC Editor function is currently provided by the

Internet Society.

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
2023年上半年GDP全球前十五强
 百态   2023-10-24
美众议院议长启动对拜登的弹劾调查
 百态   2023-09-13
上海、济南、武汉等多地出现不明坠落物
 探索   2023-09-06
印度或要将国名改为“巴拉特”
 百态   2023-09-06
男子为女友送行,买票不登机被捕
 百态   2023-08-20
手机地震预警功能怎么开?
 干货   2023-08-06
女子4年卖2套房花700多万做美容:不但没变美脸,面部还出现变形
 百态   2023-08-04
住户一楼被水淹 还冲来8头猪
 百态   2023-07-31
女子体内爬出大量瓜子状活虫
 百态   2023-07-25
地球连续35年收到神秘规律性信号,网友:不要回答!
 探索   2023-07-21
全球镓价格本周大涨27%
 探索   2023-07-09
钱都流向了那些不缺钱的人,苦都留给了能吃苦的人
 探索   2023-07-02
倩女手游刀客魅者强控制(强混乱强眩晕强睡眠)和对应控制抗性的关系
 百态   2020-08-20
美国5月9日最新疫情:美国确诊人数突破131万
 百态   2020-05-09
荷兰政府宣布将集体辞职
 干货   2020-04-30
倩女幽魂手游师徒任务情义春秋猜成语答案逍遥观:鹏程万里
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案神机营:射石饮羽
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案昆仑山:拔刀相助
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案天工阁:鬼斧神工
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案丝路古道:单枪匹马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:与虎谋皮
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:李代桃僵
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:指鹿为马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:小鸟依人
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:千金买邻
 干货   2019-11-12
 
推荐阅读
 
 
 
>>返回首頁<<
 
靜靜地坐在廢墟上,四周的荒凉一望無際,忽然覺得,淒涼也很美
© 2005- 王朝網路 版權所有