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RFC 8172

Informational
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Considerations for Benchmarking Virtual Network Functions and Their Infrastructure

 


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Internet Engineering Task Force (IETF)                         A. Morton
Request for Comments: 8172                                     AT&T Labs
Category: Informational                                        July 2017
ISSN: 2070-1721


       Considerations for Benchmarking Virtual Network Functions
                        and Their Infrastructure

Abstract

   The Benchmarking Methodology Working Group has traditionally
   conducted laboratory characterization of dedicated physical
   implementations of internetworking functions.  This memo investigates
   additional considerations when network functions are virtualized and
   performed in general-purpose hardware.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc8172.

Copyright Notice

   Copyright (c) 2017 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Considerations for Hardware and Testing . . . . . . . . . . .   4
     3.1.  Hardware Components . . . . . . . . . . . . . . . . . . .   4
     3.2.  Configuration Parameters  . . . . . . . . . . . . . . . .   5
     3.3.  Testing Strategies  . . . . . . . . . . . . . . . . . . .   6
     3.4.  Attention to Shared Resources . . . . . . . . . . . . . .   7
   4.  Benchmarking Considerations . . . . . . . . . . . . . . . . .   8
     4.1.  Comparison with Physical Network Functions  . . . . . . .   8
     4.2.  Continued Emphasis on Black-Box Benchmarks  . . . . . . .   8
     4.3.  New Benchmarks and Related Metrics  . . . . . . . . . . .   9
     4.4.  Assessment of Benchmark Coverage  . . . . . . . . . . . .  10
     4.5.  Power Consumption . . . . . . . . . . . . . . . . . . . .  12
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  13
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  14
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  15
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  15

1.  Introduction

   The Benchmarking Methodology Working Group (BMWG) has traditionally
   conducted laboratory characterization of dedicated physical
   implementations of internetworking functions (or physical network
   functions (PNFs)).  The black-box benchmarks of throughput, latency,
   forwarding rates, and others have served our industry for many years.
   [RFC1242] and [RFC2544] are the cornerstones of the work.

   A set of service provider and vendor development goals has emerged:
   reduce costs while increasing flexibility of network devices and
   drastically reduce deployment time.  Network Function Virtualization
   (NFV) has the promise to achieve these goals and therefore has
   garnered much attention.  It now seems certain that some network
   functions will be virtualized following the success of cloud
   computing and virtual desktops supported by sufficient network path
   capacity, performance, and widespread deployment; many of the same
   techniques will help achieve NFV.

   In the context of Virtual Network Functions (VNFs), the supporting
   Infrastructure requires general-purpose computing systems, storage
   systems, networking systems, virtualization support systems (such as
   hypervisors), and management systems for the virtual and physical
   resources.  There will be many potential suppliers of Infrastructure

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   systems and significant flexibility in configuring the systems for
   best performance.  There are also many potential suppliers of VNFs,
   adding to the combinations possible in this environment.  The
   separation of hardware and software suppliers has a profound
   implication on benchmarking activities: much more of the internal
   configuration of the black-box Device Under Test (DUT) must now be
   specified and reported with the results, to foster both repeatability
   and comparison testing at a later time.

   Consider the following user story as further background and
   motivation:

      I'm designing and building my NFV Infrastructure platform.  The
      first steps were easy because I had a small number of categories
      of VNFs to support and the VNF vendor gave hardware
      recommendations that I followed.  Now I need to deploy more VNFs
      from new vendors, and there are different hardware
      recommendations.  How well will the new VNFs perform on my
      existing hardware?  Which among several new VNFs in a given
      category are most efficient in terms of capacity they deliver?
      And, when I operate multiple categories of VNFs (and PNFs)
      *concurrently* on a hardware platform such that they share
      resources, what are the new performance limits, and what are the
      software design choices I can make to optimize my chosen hardware
      platform?  Conversely, what hardware platform upgrades should I
      pursue to increase the capacity of these concurrently operating
      VNFs?

   See <http://www.etsi.org/technologies-clusters/technologies/nfv> for
   more background; the white papers there may be a useful starting
   place.  The "NFV Performance & Portability Best Practices" document
   [NFV.PER001] is particularly relevant to BMWG.  There are also
   documents available among the Approved ETSI NFV Specifications
   [Approved_ETSI_NFV], including documents describing Infrastructure
   performance aspects and service quality metrics, and drafts in the
   ETSI NFV Open Area [Draft_ETSI_NFV], which may also have relevance to
   benchmarking.

1.1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

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2.  Scope

   At the time of this writing, BMWG is considering the new topic of
   Virtual Network Functions and related Infrastructure to ensure that
   common issues are recognized from the start; background materials
   from respective standards development organizations and Open Source
   development projects (e.g., IETF, ETSI NFV, and the Open Platform for
   Network Function Virtualization (OPNFV)) are being used.

   This memo investigates additional methodological considerations
   necessary when benchmarking VNFs instantiated and hosted in general-
   purpose hardware, using bare metal hypervisors [BareMetal] or other
   isolation environments such as Linux containers.  An essential
   consideration is benchmarking physical and Virtual Network Functions
   in the same way when possible, thereby allowing direct comparison.
   Benchmarking combinations of physical and virtual devices and
   functions in a System Under Test (SUT) is another topic of keen
   interest.

   A clearly related goal is investigating benchmarks for the capacity
   of a general-purpose platform to host a plurality of VNF instances.
   Existing networking technology benchmarks will also be considered for
   adaptation to NFV and closely associated technologies.

   A non-goal is any overlap with traditional computer benchmark
   development and their specific metrics (e.g., SPECmark suites such as
   SPEC CPU).

   A continued non-goal is any form of architecture development related
   to NFV and associated technologies in BMWG, consistent with all
   chartered work since BMWG began in 1989.

3.  Considerations for Hardware and Testing

   This section lists the new considerations that must be addressed to
   benchmark VNF(s) and their supporting Infrastructure.  The SUT is
   composed of the hardware platform components, the VNFs installed, and
   many other supporting systems.  It is critical to document all
   aspects of the SUT to foster repeatability.

3.1.  Hardware Components

   The following new hardware components will become part of the test
   setup:

   1.  High-volume server platforms (general-purpose, possibly with
       virtual technology enhancements)

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   2.  Storage systems with large capacity, high speed, and high
       reliability

   3.  Network interface ports specially designed for efficient service
       of many virtual Network Interface Cards (NICs)

   4.  High-capacity Ethernet switches

   The components above are subjects for development of specialized
   benchmarks that focus on the special demands of network function
   deployment.

   Labs conducting comparisons of different VNFs may be able to use the
   same hardware platform over many studies, until the steady march of
   innovations overtakes their capabilities (as happens with the lab's
   traffic generation and testing devices today).

3.2.  Configuration Parameters

   It will be necessary to configure and document the settings for the
   entire general-purpose platform to ensure repeatability and foster
   future comparisons, including, but clearly not limited to, the
   following:

   o  number of server blades (shelf occupation)

   o  CPUs

   o  caches

   o  memory

   o  storage system

   o  I/O

   as well as configurations that support the devices that host the VNF
   itself:

   o  Hypervisor (or other forms of virtual function hosting)

   o  Virtual Machine (VM)

   o  Infrastructure virtual network (which interconnects virtual
      machines with physical network interfaces or with each other
      through virtual switches, for example)

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   and finally, the VNF itself, with items such as:

   o  specific function being implemented in VNF

   o  reserved resources for each function (e.g., CPU pinning and Non-
      Uniform Memory Access (NUMA) node assignment)

   o  number of VNFs (or sub-VNF components, each with its own VM) in
      the service function chain (see Section 1.1 of [RFC7498] for a
      definition of service function chain)

   o  number of physical interfaces and links transited in the service
      function chain

   In the physical device benchmarking context, most of the
   corresponding Infrastructure configuration choices were determined by
   the vendor.  Although the platform itself is now one of the
   configuration variables, it is important to maintain emphasis on the
   networking benchmarks and capture the platform variables as input
   factors.

3.3.  Testing Strategies

   The concept of characterizing performance at capacity limits may
   change.  For example:

   1.  It may be more representative of system capacity to characterize
       the case where the VMs hosting the VNFs are operating at 50%
       utilization and therefore sharing the "real" processing power
       across many VMs.

   2.  Another important test case stems from the need to partition (or
       isolate) network functions.  A noisy neighbor (VM hosting a VNF
       in an infinite loop) would ideally be isolated; the performance
       of other VMs would continue according to their specifications,
       and tests would evaluate the degree of isolation.

   3.  System errors will likely occur as transients, implying a
       distribution of performance characteristics with a long tail
       (like latency) and leading to the need for longer-term tests of
       each set of configuration and test parameters.

   4.  The desire for elasticity and flexibility among network functions
       will include tests where there is constant flux in the number of
       VM instances, the resources the VMs require, and the setup/
       teardown of network paths that support VM connectivity.  Requests
       for and instantiation of new VMs, along with releases for VMs
       hosting VNFs that are no longer needed, would be a normal

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       operational condition.  In other words, benchmarking should
       include scenarios with production life-cycle management of VMs
       and their VNFs and network connectivity in progress, including
       VNF scaling up/down operations, as well as static configurations.

   5.  All physical things can fail, and benchmarking efforts can also
       examine recovery aided by the virtual architecture with different
       approaches to resiliency.

   6.  The sheer number of test conditions and configuration
       combinations encourage increased efficiency, including automated
       testing arrangements, combination sub-sampling through an
       understanding of inter-relationships, and machine-readable test
       results.

3.4.  Attention to Shared Resources

   Since many components of the new NFV Infrastructure are virtual, test
   setup design must have prior knowledge of interactions/dependencies
   within the various resource domains in the SUT.  For example, a
   virtual machine performing the role of a traditional tester function,
   such as generating and/or receiving traffic, should avoid sharing any
   SUT resources with the DUT.  Otherwise, the results will have
   unexpected dependencies not encountered in physical device
   benchmarking.

   Note that the term "tester" has traditionally referred to devices
   dedicated to testing in BMWG literature.  In this new context,
   "tester" additionally refers to functions dedicated to testing, which
   may be either virtual or physical.  "Tester" has never referred to
   the individuals performing the tests.

   The possibility to use shared resources in test design while
   producing useful results remains one of the critical challenges to
   overcome.  Benchmarking setups may designate isolated resources for
   the DUT and other critical support components (such as the host/
   kernel) as the first baseline step and add other loading processes.
   The added complexity of each setup leads to shared-resource testing
   scenarios, where the characteristics of the competing load (in terms
   of memory, storage, and CPU utilization) will directly affect the
   benchmarking results (and variability of the results), but the
   results should reconcile with the baseline.

   The physical test device remains a solid foundation to compare with
   results using combinations of physical and virtual test functions or
   results using only virtual testers when necessary to assess virtual
   interfaces and other virtual functions.

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4.  Benchmarking Considerations

   This section discusses considerations related to benchmarks
   applicable to VNFs and their associated technologies.

4.1.  Comparison with Physical Network Functions

   In order to compare the performance of VNFs and system
   implementations with their physical counterparts, identical
   benchmarks must be used.  Since BMWG has already developed
   specifications for many network functions, there will be re-use of
   existing benchmarks through references, while allowing for the
   possibility of benchmark curation during development of new
   methodologies.  Consideration should be given to quantifying the
   number of parallel VNFs required to achieve comparable scale/capacity
   with a given physical device or whether some limit of scale was
   reached before the VNFs could achieve the comparable level.  Again,
   implementation based on different hypervisors or other virtual
   function hosting remain as critical factors in performance
   assessment.

4.2.  Continued Emphasis on Black-Box Benchmarks

   When the network functions under test are based on open-source code,
   there may be a tendency to rely on internal measurements to some
   extent, especially when the externally observable phenomena only
   support an inference of internal events (such as routing protocol
   convergence observed in the data plane).  Examples include CPU/Core
   utilization, network utilization, storage utilization, and memory
   committed/used.  These "white-box" metrics provide one view of the
   resource footprint of a VNF.  Note that the resource utilization
   metrics do not easily match the 3x4 Matrix, described in Section 4.4.

   However, external observations remain essential as the basis for
   benchmarks.  Internal observations with fixed specification and
   interpretation may be provided in parallel (as auxiliary metrics), to
   assist the development of operations procedures when the technology
   is deployed, for example.  Internal metrics and measurements from
   open-source implementations may be the only direct source of
   performance results in a desired dimension, but corroborating
   external observations are still required to assure the integrity of
   measurement discipline was maintained for all reported results.

   A related aspect of benchmark development is where the scope includes
   multiple approaches to a common function under the same benchmark.
   For example, there are many ways to arrange for activation of a
   network path between interface points, and the activation times can
   be compared if the start-to-stop activation interval has a generic

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   and unambiguous definition.  Thus, generic benchmark definitions are
   preferred over technology/protocol-specific definitions where
   possible.

4.3.  New Benchmarks and Related Metrics

   There will be new classes of benchmarks needed for network design and
   assistance when developing operational practices (possibly automated
   management and orchestration of deployment scale).  Examples follow
   in the paragraphs below, many of which are prompted by the goals of
   increased elasticity and flexibility of the network functions, along
   with reduced deployment times.

   o  Time to deploy VNFs: In cases where the general-purpose hardware
      is already deployed and ready for service, it is valuable to know
      the response time when a management system is tasked with
      "standing up" 100s of virtual machines and the VNFs they will
      host.

   o  Time to migrate VNFs: In cases where a rack or shelf of hardware
      must be removed from active service, it is valuable to know the
      response time when a management system is tasked with "migrating"
      some number of virtual machines and the VNFs they currently host
      to alternate hardware that will remain in service.

   o  Time to create a virtual network in the general-purpose
      Infrastructure: This is a somewhat simplified version of existing
      benchmarks for convergence time, in that the process is initiated
      by a request from (centralized or distributed) control, rather
      than inferred from network events (link failure).  The successful
      response time would remain dependent on data-plane observations to
      confirm that the network is ready to perform.

   o  Effect of verification measurements on performance: A complete
      VNF, or something as simple as a new policy to implement in a VNF,
      is implemented.  The action to verify instantiation of the VNF or
      policy could affect performance during normal operation.

   Also, it appears to be valuable to measure traditional packet
   transfer performance metrics during the assessment of traditional and
   new benchmarks, including metrics that may be used to support service
   engineering such as the spatial composition metrics found in
   [RFC6049].  Examples include mean one-way delay in Section 4.1 of
   [RFC6049], Packet Delay Variation (PDV) in [RFC5481], and Packet
   Reordering [RFC4737] [RFC4689].

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4.4.  Assessment of Benchmark Coverage

   It can be useful to organize benchmarks according to their applicable
   life-cycle stage and the performance criteria they were designed to
   assess.  The table below (derived from [X3.102]) provides a way to
   organize benchmarks such that there is a clear indication of coverage
   for the intersection of life-cycle stages and performance criteria.

   |----------------------------------------------------------|
   |               |             |            |               |
   |               |   SPEED     |  ACCURACY  |  RELIABILITY  |
   |               |             |            |               |
   |----------------------------------------------------------|
   |               |             |            |               |
   |  Activation   |             |            |               |
   |               |             |            |               |
   |----------------------------------------------------------|
   |               |             |            |               |
   |  Operation    |             |            |               |
   |               |             |            |               |
   |----------------------------------------------------------|
   |               |             |            |               |
   | De-activation |             |            |               |
   |               |             |            |               |
   |----------------------------------------------------------|

   For example, the "Time to deploy VNFs" benchmark described above
   would be placed in the intersection of Activation and Speed, making
   it clear that there are other potential performance criteria to
   benchmark, such as the "percentage of unsuccessful VM/VNF stand-ups"
   in a set of 100 attempts.  This example emphasizes that the
   Activation and De-activation life-cycle stages are key areas for NFV
   and related Infrastructure and encourages expansion beyond
   traditional benchmarks for normal operation.  Thus, reviewing the
   benchmark coverage using this table (sometimes called the 3x3 Matrix)
   can be a worthwhile exercise in BMWG.

   In one of the first applications of the 3x3 Matrix in BMWG
   [SDN-BENCHMARK], we discovered that metrics on measured size,
   capacity, or scale do not easily match one of the three columns
   above.  Following discussion, this was resolved in two ways:

   o  Add a column, Scale, for use when categorizing and assessing the
      coverage of benchmarks (without measured results).  An example of
      this use is found in [OPNFV-BENCHMARK] (and a variation may be
      found in [SDN-BENCHMARK]).  This is the 3x4 Matrix.

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   o  If using the matrix to report results in an organized way, keep
      size, capacity, and scale metrics separate from the 3x3 Matrix and
      incorporate them in the report with other qualifications of the
      results.

   Note that the resource utilization (e.g., CPU) metrics do not fit in
   the matrix.  They are not benchmarks, and omitting them confirms
   their status as auxiliary metrics.  Resource assignments are
   configuration parameters, and these are reported separately.

   This approach encourages use of the 3x3 Matrix to organize reports of
   results, where the capacity at which the various metrics were
   measured could be included in the title of the matrix (and results
   for multiple capacities would result in separate 3x3 Matrices, if
   there were sufficient measurements/results to organize in that way).

   For example, results for each VM and VNF could appear in the 3x3
   Matrix, organized to illustrate resource occupation (CPU Cores) in a
   particular physical computing system, as shown below.

                 VNF#1
             .-----------.
             |__|__|__|__|
   Core 1    |__|__|__|__|
             |__|__|__|__|
             |  |  |  |  |
             '-----------'
                 VNF#2
             .-----------.
             |__|__|__|__|
   Cores 2-5 |__|__|__|__|
             |__|__|__|__|
             |  |  |  |  |
             '-----------'
                 VNF#3             VNF#4             VNF#5
             .-----------.    .-----------.     .-----------.
             |__|__|__|__|    |__|__|__|__|     |__|__|__|__|
   Core 6    |__|__|__|__|    |__|__|__|__|     |__|__|__|__|
             |__|__|__|__|    |__|__|__|__|     |__|__|__|__|
             |  |  |  |  |    |  |  |  |  |     |  |  |  |  |
             '-----------'    '-----------'     '-----------'
                  VNF#6
             .-----------.
             |__|__|__|__|
   Core 7    |__|__|__|__|
             |__|__|__|__|
             |  |  |  |  |
             '-----------'

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   The combination of tables above could be built incrementally,
   beginning with VNF#1 and one Core, then adding VNFs according to
   their supporting Core assignments.  X-Y plots of critical benchmarks
   would also provide insight to the effect of increased hardware
   utilization.  All VNFs might be of the same type, or to match a
   production environment, there could be VNFs of multiple types and
   categories.  In this figure, VNFs #3-#5 are assumed to require small
   CPU resources, while VNF#2 requires four Cores to perform its
   function.

4.5.  Power Consumption

   Although there is incomplete work to benchmark physical network
   function power consumption in a meaningful way, the desire to measure
   the physical Infrastructure supporting the virtual functions only
   adds to the need.  Both maximum power consumption and dynamic power
   consumption (with varying load) would be useful.  The Intelligent
   Platform Management Interface (IPMI) standard [IPMI2.0] has been
   implemented by many manufacturers and supports measurement of
   instantaneous energy consumption.

   To assess the instantaneous energy consumption of virtual resources,
   it may be possible to estimate the value using an overall metric
   based on utilization readings, according to [NFVIaas-FRAMEWORK].

5.  Security Considerations

   Benchmarking activities as described in this memo are limited to
   technology characterization of a DUT/SUT using controlled stimuli in
   a laboratory environment, with dedicated address space and the
   constraints specified in the sections above.

   The benchmarking network topology will be an independent test setup
   and MUST NOT be connected to devices that may forward the test
   traffic into a production network or misroute traffic to the test
   management network.

   Further, benchmarking is performed on a "black-box" basis, relying
   solely on measurements observable external to the DUT/SUT.

   Special capabilities SHOULD NOT exist in the DUT/SUT specifically for
   benchmarking purposes.  Any implications for network security arising
   from the DUT/SUT SHOULD be identical in the lab and in production
   networks.

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6.  IANA Considerations

   This document does not require any IANA actions.

7.  References

7.1.  Normative References

   [NFV.PER001]
              ETSI, "Network Function Virtualization: Performance &
              Portability Best Practices", ETSI GS NFV-PER 001, V1.1.2,
              December 2014.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2544]  Bradner, S. and J. McQuaid, "Benchmarking Methodology for
              Network Interconnect Devices", RFC 2544,
              DOI 10.17487/RFC2544, March 1999,
              <http://www.rfc-editor.org/info/rfc2544>.

   [RFC4689]  Poretsky, S., Perser, J., Erramilli, S., and S. Khurana,
              "Terminology for Benchmarking Network-layer Traffic
              Control Mechanisms", RFC 4689, DOI 10.17487/RFC4689,
              October 2006, <http://www.rfc-editor.org/info/rfc4689>.

   [RFC4737]  Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
              S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
              DOI 10.17487/RFC4737, November 2006,
              <http://www.rfc-editor.org/info/rfc4737>.

   [RFC7498]  Quinn, P., Ed. and T. Nadeau, Ed., "Problem Statement for
              Service Function Chaining", RFC 7498,
              DOI 10.17487/RFC7498, April 2015,
              <http://www.rfc-editor.org/info/rfc7498>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <http://www.rfc-editor.org/info/rfc8174>.

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7.2.  Informative References

   [Approved_ETSI_NFV]
              ETSI, Network Functions Virtualisation Technical
              Committee, "ETSI NFV",
              <http://www.etsi.org/standards-search>.

   [BareMetal]
              Popek, G. and R. Goldberg, "Formal requirements for
              virtualizable third generation architectures",
              Communications of the ACM, Volume 17, Issue 7, Pages
              412-421, DOI 10.1145/361011.361073, July 1974.

   [Draft_ETSI_NFV]
              ETSI, "Network Functions Virtualisation: Specifications",
              <http://www.etsi.org/technologies-clusters/technologies/
              nfv>.

   [IPMI2.0]  Intel Corporation, Hewlett-Packard Company, NEC
              Corporation, and Dell Inc., "Intelligent Platform
              Management Interface Specification v2.0 (with latest
              errata)", April 2015,
              <http://www.intel.com/content/dam/www/public/us/en/
              documents/specification-updates/ipmi-intelligent-platform-
              mgt-interface-spec-2nd-gen-v2-0-spec-update.pdf>.

   [NFVIaas-FRAMEWORK]
              Krishnan, R., Figueira, N., Krishnaswamy, D., Lopez, D.,
              Wright, S., Hinrichs, T., Krishnaswamy, R., and A. Yerra,
              "NFVIaaS Architectural Framework for Policy Based Resource
              Placement and Scheduling", Work in Progress,
              draft-krishnan-nfvrg-policy-based-rm-nfviaas-06, March
              2016.

   [OPNFV-BENCHMARK]
              Tahhan, M., O'Mahony, B., and A. Morton, "Benchmarking
              Virtual Switches in OPNFV", Work in Progress,
              draft-ietf-bmwg-vswitch-opnfv-04, June 2017.

   [RFC1242]  Bradner, S., "Benchmarking Terminology for Network
              Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242,
              July 1991, <http://www.rfc-editor.org/info/rfc1242>.

   [RFC5481]  Morton, A. and B. Claise, "Packet Delay Variation
              Applicability Statement", RFC 5481, DOI 10.17487/RFC5481,
              March 2009, <http://www.rfc-editor.org/info/rfc5481>.

Top      ToC       Page 15 
   [RFC6049]  Morton, A. and E. Stephan, "Spatial Composition of
              Metrics", RFC 6049, DOI 10.17487/RFC6049, January 2011,
              <http://www.rfc-editor.org/info/rfc6049>.

   [SDN-BENCHMARK]
              Vengainathan, B., Basil, A., Tassinari, M., Manral, V.,
              and S. Banks, "Terminology for Benchmarking SDN Controller
              Performance", Work in Progress, draft-ietf-bmwg-sdn-
              controller-benchmark-term-04, June 2017.

   [X3.102]   ANSI, "Information Systems - Data Communication Systems
              and Services - User-Oriented Performance Parameters
              Communications Framework", ANSI X3.102, 1983.

Acknowledgements

   The author acknowledges an encouraging conversation on this topic
   with Mukhtiar Shaikh and Ramki Krishnan in November 2013.  Bhavani
   Parise and Ilya Varlashkin have provided useful suggestions to expand
   these considerations.  Bhuvaneswaran Vengainathan has already tried
   the 3x3 Matrix with the SDN controller document and contributed to
   many discussions.  Scott Bradner quickly pointed out shared resource
   dependencies in an early vSwitch measurement proposal, and the topic
   was included here as a key consideration.  Further development was
   encouraged by Barry Constantine's comments following the BMWG session
   at IETF 92: the session itself was an affirmation for this memo.
   There have been many interesting contributions from Maryam Tahhan,
   Marius Georgescu, Jacob Rapp, Saurabh Chattopadhyay, and others.

Author's Address

   Al Morton
   AT&T Labs
   200 Laurel Avenue South
   Middletown, NJ  07748
   United States of America

   Phone: +1 732 420 1571
   Fax:   +1 732 368 1192
   Email: acmorton@att.com