draft-ietf-bmwg-2544-as-03.txt   draft-ietf-bmwg-2544-as-04.txt 
Network Working Group S. Bradner Network Working Group S. Bradner
Internet-Draft Harvard University Internet-Draft Harvard University
Intended status: Informational K. Dubray Intended status: Informational K. Dubray
Expires: October 28, 2012 Juniper Networks Expires: December 14, 2012 Juniper Networks
J. McQuaid J. McQuaid
Turnip Video Turnip Video
A. Morton A. Morton
AT&T Labs AT&T Labs
April 26, 2012 June 12, 2012
RFC 2544 Applicability Statement: Use on Production Networks Considered RFC 2544 Applicability Statement: Use on Production Networks Considered
Harmful Harmful
draft-ietf-bmwg-2544-as-03 draft-ietf-bmwg-2544-as-04
Abstract Abstract
Benchmarking Methodology Working Group (BMWG) has been developing key Benchmarking Methodology Working Group (BMWG) has been developing key
performance metrics and laboratory test methods since 1990, and performance metrics and laboratory test methods since 1990, and
continues this work at present. Recent application of the methods continues this work at present. Recent application of the methods
beyond their intended scope is cause for concern. This memo beyond their intended scope is cause for concern. The methods
clarifies the scope of RFC 2544 and other benchmarking work for the described in RFC 2544, where overload is a possible outcome, would no
IETF community. doubt be harmful to user traffic performance on a production network.
This memo clarifies the scope of RFC 2544 and other benchmarking work
for the IETF community.
Status of this Memo Status of this Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on October 28, 2012. This Internet-Draft will expire on December 14, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 3
2. Scope and Goals . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Scope and Goals . . . . . . . . . . . . . . . . . . . . . . . . 4
3. The Concept of an Isolated Test Environment . . . . . . . . . . 4 3. The Concept of an Isolated Test Environment . . . . . . . . . . 4
4. Why RFC 2544 Methods are intended for ITE . . . . . . . . . . . 4 4. Why RFC 2544 Methods are intended for ITE . . . . . . . . . . . 4
4.1. Experimental Control, Repeatability, and Accuracy . . . . . 4 4.1. Experimental Control and Accuracy . . . . . . . . . . . . . 4
4.2. Containment of Implementation Failure Impact . . . . . . . 5 4.2. Containing Damage . . . . . . . . . . . . . . . . . . . . . 5
5. Advisory on RFC 2544 Methods in Real-world Networks . . . . . . 5 5. Advisory on RFC 2544 Methods in Production Networks . . . . . . 5
6. What to do without RFC 2544? . . . . . . . . . . . . . . . . . 6 6. What to do without RFC 2544? . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . . 7 10.1. Normative References . . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . . 8 10.2. Informative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
This memo clarifies the scope of RFC 2544 [RFC2544], and other This memo clarifies the scope of RFC 2544 [RFC2544], which discusses
and defines several tests that may be used to characterize the
performance of a network interconnecting device, and other
benchmarking work for the IETF community. benchmarking work for the IETF community.
Benchmarking Methodologies (beginning with [RFC2544]) have always Benchmarking Methodologies (beginning with [RFC2544]) have always
relied on test conditions that can only be produced and replicated relied on test conditions that can only be produced and replicated
reliably in the laboratory. Thus it was surprising to find that this reliably in the laboratory. Thus it was unfortunate to find that
foundation methodology was being cited in several unintended this foundation methodology was being cited in several unintended
specifications [Y.1731] and products performing applications such as: specifications and products performing applications such as:
1. Validation of telecommunication service configuration, such as 1. Validation of telecommunication service configuration, such as
the Committed Information Rate (CIR). the Committed Information Rate (CIR).
2. Validation of performance metrics in a telecommunication Service 2. Validation of performance metrics in a telecommunication Service
Level Agreement (SLA), such as frame loss and latency. Level Agreement (SLA), such as frame loss and latency.
3. Telecommunication service activation testing, where traffic that 3. Telecommunication service activation testing, where traffic that
shares network resources with the test might be adversely shares network resources with the test might be adversely
affected. affected.
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between specified interfaces at different geographic locations) from between specified interfaces at different geographic locations) from
the generic term "service". Below, we use the adjective "production" the generic term "service". Below, we use the adjective "production"
to refer to networks carrying live user traffic. [RFC2544] used the to refer to networks carrying live user traffic. [RFC2544] used the
term "real-world" to refer to production networks and to term "real-world" to refer to production networks and to
differentiate them from test networks. differentiate them from test networks.
Although RFC 2544 is held up as the standard reference for such Although RFC 2544 is held up as the standard reference for such
testing, we believe that the actual methods used vary from RFC 2544 testing, we believe that the actual methods used vary from RFC 2544
in significant ways. Since the only citation is to RFC 2544, the in significant ways. Since the only citation is to RFC 2544, the
modifications are opaque to the standards community and to users in modifications are opaque to the standards community and to users in
general (an undesirable situation). general (an undesirable situation). There is risk of harm to user
traffic from applying the test traffic and methods described in
[RFC2544] on a production network, because overload in shared
resources is a possible outcome.
To directly address this situation, the past and present Chairs of To directly address this situation, the past and present Chairs of
the IETF Benchmarking Methodology Working Group (BMWG) have prepared the IETF Benchmarking Methodology Working Group (BMWG) have prepared
this Applicability Statement for RFC 2544. this Applicability Statement for RFC 2544.
1.1. Requirements Language 1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
2. Scope and Goals 2. Scope and Goals
This memo clarifies the scope of [RFC2544], with the goal to provide This memo clarifies the scope of [RFC2544], with the goal to provide
guidance to the community on its applicability, which is limited to guidance to the community on its applicability, which is limited to
laboratory testing. laboratory testing.
3. The Concept of an Isolated Test Environment 3. The Concept of an Isolated Test Environment
An Isolated Test Environment (ITE) used with [RFC2544] methods (as An Isolated Test Environment (ITE) used with [RFC2544] methods (as
illustrated in Figures 1 through 3 of [RFC2544])has the ability to: illustrated in Figures 1 through 3 of [RFC2544]) has the ability to:
o contain the test streams to paths within the desired set-up o contain the test streams to paths within the desired set-up
o prevent non-test traffic from traversing the test set-up o prevent non-test traffic from traversing the test set-up
These features allow unfettered experimentation, while at the same These features allow unfettered experimentation, while at the same
time protecting equipment management LANs and other production time protecting lab equipment management/control LANs and other
networks from the unwanted effects of the test traffic. production networks from the unwanted effects of the test traffic.
4. Why RFC 2544 Methods are intended for ITE 4. Why RFC 2544 Methods are intended for ITE
The following sections discuss some of the reasons why RFC 2544 The following sections discuss some of the reasons why RFC 2544
[RFC2544] methods were intended only for isolated laboratory use, and [RFC2544] methods were intended only for isolated laboratory use, and
the difficulties of applying these methods outside the lab the difficulties of applying these methods outside the lab
environment. environment.
4.1. Experimental Control, Repeatability, and Accuracy 4.1. Experimental Control and Accuracy
All of the tests described in RFC 2544 assume that the tester and All of the tests described in RFC 2544 require that the tester and
device under test are the only devices on the networks that are device under test are the only devices on the networks that are
transmitting data. The presence of other unwanted traffic on the transmitting data. The presence of other unwanted traffic on the
network would mean that the specified test conditions have not been network would mean that the specified test conditions have not been
achieved. achieved.
Assuming that the unwanted traffic appears in variable amounts over If any unwanted traffic appears and the amount varies over time, the
time, the repeatability of any test result will likely depend to some repeatability of any test result will likely depend to some degree on
degree on the unwanted traffic. the unwanted traffic.
The presence of unwanted or unknown traffic makes accurate, The presence of unwanted or unknown traffic makes accurate,
repeatable, and consistent measurements of the performance of the repeatable, and consistent measurements of the performance of the
device under test very unlikely, since the actual test conditions device under test very unlikely, since the complete details of test
will not be reported. conditions will not be reported.
For example, the RFC 2544 Throughput Test attempts to characterize a For example, the RFC 2544 Throughput Test attempts to characterize a
maximum reliable load, thus there will be testing above the maximum maximum reliable load, thus there will be testing above the maximum
that causes packet/frame loss. Any other sources of traffic on the that causes packet/frame loss. Any other sources of traffic on the
network will cause packet loss to occur at a tester data rate lower network will cause packet loss to occur at a tester data rate lower
than the rate that would be achieved without the extra traffic. than the rate that would be achieved without the extra traffic.
4.2. Containment of Implementation Failure Impact 4.2. Containing Damage
RFC 2544 methods, specifically to determine Throughput as defined in RFC 2544 methods, specifically to determine Throughput as defined in
[RFC1242] and other benchmarks, may overload the resources of the [RFC1242] and other benchmarks, may overload the resources of the
device under test, and may cause failure modes in the device under device under test, and may cause failure modes in the device under
test. Since failures can become the root cause of more wide-spread test. Since failures can become the root cause of more wide-spread
failure, it is clearly desirable to contain all test traffic within failure, it is clearly desirable to contain all test traffic within
the ITE. the ITE.
In addition, such testing can have a negative affect on any traffic In addition, such testing can have a negative effect on any traffic
which shares resources with the test stream(s) since, in most cases, that shares resources with the test stream(s) since, in most cases,
the traffic load will be close to the capacity of the network links. the traffic load will be close to the capacity of the network links.
Appendix C.2.2 of [RFC2544] (as adjusted by errata) gives the private Appendix C.2.2 of [RFC2544] (as adjusted by errata) gives the private
IPv4 address range for testing: IPv4 address range for testing:
"...The network addresses 198.18.0.0 through 198.19.255.255 have been "...The network addresses 198.18.0.0 through 198.19.255.255 have been
assigned to the BMWG by the IANA for this purpose. This assignment assigned to the BMWG by the IANA for this purpose. This assignment
was made to minimize the chance of conflict in case a testing device was made to minimize the chance of conflict in case a testing device
were to be accidentally connected to part of the Internet. The were to be accidentally connected to part of the Internet. The
specific use of the addresses is detailed below." specific use of the addresses is detailed below."
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to discard any traffic they observe in this address range, as it is to discard any traffic they observe in this address range, as it is
intended for laboratory ITE use only. Thus, testers using the intended for laboratory ITE use only. Thus, testers using the
assigned testing address ranges MUST NOT be connected to the assigned testing address ranges MUST NOT be connected to the
Internet. Internet.
We note that a range of IPv6 addresses has been assigned to BMWG for We note that a range of IPv6 addresses has been assigned to BMWG for
laboratory test purposes, in [RFC5180]. Also, the strong statements laboratory test purposes, in [RFC5180]. Also, the strong statements
in the Security Considerations Section of this memo make the scope in the Security Considerations Section of this memo make the scope
even more clear; this is now a standard fixture of all BMWG memos. even more clear; this is now a standard fixture of all BMWG memos.
5. Advisory on RFC 2544 Methods in Real-world Networks 5. Advisory on RFC 2544 Methods in Production Networks
The tests in [RFC2544] were designed to measure the performance of The tests in [RFC2544] were designed to measure the performance of
network devices, not of networks, and certainly not production network devices, not of networks, and certainly not production
networks carrying user traffic on shared resources. There will be networks carrying user traffic on shared resources. There will be
unanticipated difficulties when applying these methods outside the unanticipated difficulties when applying these methods outside the
lab environment. lab environment.
Operating test equipment on production networks according to the Operating test equipment on production networks according to the
methods described in [RFC2544], where overload is a possible outcome, methods described in [RFC2544], where overload is a possible outcome,
would no doubt be harmful to user traffic performance. These tests would no doubt be harmful to user traffic performance. These tests
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IPPM has not yet standardized methods for raw capacity measurement of IPPM has not yet standardized methods for raw capacity measurement of
Internet paths. Such testing needs to adequately consider the strong Internet paths. Such testing needs to adequately consider the strong
possibility for degradation to any other traffic that may be present possibility for degradation to any other traffic that may be present
due to congestion. There are no specific methods proposed for due to congestion. There are no specific methods proposed for
activation of a packet transfer service in IPPM. activation of a packet transfer service in IPPM.
Other standards may help to fill gaps in telecommunication service Other standards may help to fill gaps in telecommunication service
testing. For example, the IETF has many standards intended to assist testing. For example, the IETF has many standards intended to assist
with network operation, administration and maintenance (OAM), and with network operation, administration and maintenance (OAM), and
ITU-T Study Group 12 has a recommendation on service activation test ITU-T Study Group 12 has a recommendation on service activation test
methodology. methodology [Y.1564].
The world will not spin off axis while waiting for appropriate and The world will not spin off axis while waiting for appropriate and
standardized methods to emerge from the consensus process. standardized methods to emerge from the consensus process.
7. Security Considerations 7. Security Considerations
This Applicability Statement is also intended to help preserve the This Applicability Statement intends to help preserve the security of
security of the Internet by clarifying that the scope of [RFC2544] the Internet by clarifying that the scope of [RFC2544] and other BMWG
and other BMWG memos are all limited to testing in a laboratory ITE, memos are all limited to testing in a laboratory ITE, thus avoiding
thus avoiding accidental Denial of Service attacks or congestion due accidental Denial of Service attacks or congestion due to high
to high traffic volume test streams. traffic volume test streams.
All Benchmarking activities are limited to technology All Benchmarking activities are limited to technology
characterization using controlled stimuli in a laboratory characterization using controlled stimuli in a laboratory
environment, with dedicated address space and the other constraints environment, with dedicated address space and the other constraints
[RFC2544]. [RFC2544].
The benchmarking network topology will be an independent test setup The benchmarking network topology will be an independent test setup
and MUST NOT be connected to devices that may forward the test and MUST NOT be connected to devices that may forward the test
traffic into a production network, or misroute traffic to the test traffic into a production network, or misroute traffic to the test
management network. management network.
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[RFC1242] Bradner, S., "Benchmarking terminology for network [RFC1242] Bradner, S., "Benchmarking terminology for network
interconnection devices", RFC 1242, July 1991. interconnection devices", RFC 1242, July 1991.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for [RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
Network Interconnect Devices", RFC 2544, March 1999. Network Interconnect Devices", RFC 2544, March 1999.
[RFC5180] Popoviciu, C., Hamza, A., Van de Velde, G., and D. [RFC5180] Popoviciu, C., Hamza, A., Van de Velde, G., and D.
Dugatkin, "IPv6 Benchmarking Methodology for Network Dugatkin, "IPv6 Benchmarking Methodology for Network
Interconnect Devices", RFC 5180, May 2008. Interconnect Devices", RFC 5180, May 2008.
10.2. Informative References 10.2. Informative References
[Y.1731] ITU-T Recommendation Y.1540, "OAM functions and mechanisms [Y.1564] ITU-T Recommendation Y.1564, "Ethernet Service Activation
for Ethernet based networks", April 2011. Test Methodology", March 2011.
Authors' Addresses Authors' Addresses
Scott Bradner Scott Bradner
Harvard University Harvard University
29 Oxford St. 29 Oxford St.
Cambridge, MA 02138 Cambridge, MA 02138
USA USA
Phone: +1 617 495 3864 Phone: +1 617 495 3864
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