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BMWG                                                        R. Rosa, Ed.
Internet-Draft                                             C. Rothenberg
Intended status: Informational                                   UNICAMP
Expires: July 2, 2019                                         M. Peuster
                                                                 H. Karl
                                                                     UPB
                                                       December 29, 2018


              Methodology for VNF Benchmarking Automation
                      draft-rosa-bmwg-vnfbench-03

Abstract

   This document describes a common methodology for the automated
   benchmarking of Virtualized Network Functions (VNFs) executed on
   general-purpose hardware.  Specific cases of benchmarking
   methodologies for particular VNFs can be derived from this document.
   Two open source reference implementations are reported as running
   code embodiments of the proposed, automated benchmarking methodology.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on July 2, 2019.

Copyright Notice

   Copyright (c) 2018 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
   (https://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



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   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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  Considerations  . . . . . . . . . . . . . . . . . . . . . . .   5
   4.1.  VNF Testing Methods . . . . . . . . . . . . . . . . . . . .   5
   4.2.  Benchmarking Procedures . . . . . . . . . . . . . . . . . .   6
   5.  A Generic VNF Benchmarking Architectural Framework  . . . . .   7
   5.1.  Deployment Scenarios  . . . . . . . . . . . . . . . . . . .   9
   6.  Methodology . . . . . . . . . . . . . . . . . . . . . . . . .  10
   6.1.  VNF Benchmarking Descriptor (VNF-BD)  . . . . . . . . . . .  11
   6.1.1.  Descriptor Headers  . . . . . . . . . . . . . . . . . . .  11
   6.1.2.  Target Information  . . . . . . . . . . . . . . . . . . .  11
   6.1.3.  Deployment Scenario . . . . . . . . . . . . . . . . . . .  11
   6.1.4.  Settings  . . . . . . . . . . . . . . . . . . . . . . . .  12
   6.2.  VNF Performance Profile (VNF-PP)  . . . . . . . . . . . . .  13
   6.2.1.  Execution Environment . . . . . . . . . . . . . . . . . .  13
   6.2.2.  Measurement Results . . . . . . . . . . . . . . . . . . .  14
   6.3.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . .  15
   6.3.1.  Pre-Execution . . . . . . . . . . . . . . . . . . . . . .  15
   6.3.2.  Automated Execution . . . . . . . . . . . . . . . . . . .  15
   6.3.3.  Post-Execution  . . . . . . . . . . . . . . . . . . . . .  17
   6.4.  Particular Cases  . . . . . . . . . . . . . . . . . . . . .  17
   6.4.1.  Capacity  . . . . . . . . . . . . . . . . . . . . . . . .  17
   6.4.2.  Isolation . . . . . . . . . . . . . . . . . . . . . . . .  17
   6.4.3.  Failure Handling  . . . . . . . . . . . . . . . . . . . .  18
   6.4.4.  Elasticity and Flexibility  . . . . . . . . . . . . . . .  18
   6.4.5.  Handling Configurations . . . . . . . . . . . . . . . . .  18
   6.4.6.  White Box VNF . . . . . . . . . . . . . . . . . . . . . .  18
   7.  Relevant Influencing Aspects  . . . . . . . . . . . . . . . .  18
   8.  Open Source Reference Implementations . . . . . . . . . . . .  19
   8.1.  Gym . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
   8.2.  tng-bench . . . . . . . . . . . . . . . . . . . . . . . . .  21
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  22
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  22
   11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . .  22
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  22
   12.1.  Normative References . . . . . . . . . . . . . . . . . . .  22
   12.2.  Informative References . . . . . . . . . . . . . . . . . .  23
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  24





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1.  Introduction

   The Benchmarking Methodology Working Group (BMWG) already presented
   considerations for benchmarking of VNFs and their infrastructure in
   [RFC8172].  Similar to the motivation given in [RFC8172], the
   following aspects motivate the need for VNF benchmarking: (i) pre-
   deployment infrastructure dimensioning to realize associated VNF
   performance profiles; (ii) comparison factor with physical network
   functions; (iii) and output results for analytical VNF development.

   Even if many methodologies already described by the BMWG, e.g., self-
   contained black-box benchmarking, can be applied to VNF benchmarking
   scenarios, further considerations have to be made.  This is, on the
   one hand, because VNFs, which are software components, do not have
   strict and clear execution boundaries and depend on underlying
   virtualization environment parameters as well as management and
   orchestration decisions [ETS14a].  On the other hand, can and should
   the flexible, software-based nature of VNFs be exploited to fully
   automate the entire benchmarking procedure end-to-end.  This is an
   inherent need to align VNF benchmarking with the agile methods
   enabled by the concept of network function virtualization (NFV)
   [ETS14e] More specifically it allows: (i) the development of agile
   performance-focused DevOps methodologies for Continuous Integration
   and Delivery (CI/CD) of VNFs; (ii) the creation of on-demand VNF test
   descriptors for upcoming execution environments; (iii) the path for
   precise-analytics of extensively automated catalogues of VNF
   performance profiles; (iv) and run-time mechanisms to assist VNF
   lifecycle orchestration/management workflows, e.g., automated
   resource dimensioning based on benchmarking insights.

   This document describes basic methodologies and guidelines to fully
   automate VNF benchmarking procedures, without limiting the automated
   process to a specific benchmark or infrastructure.  After presenting
   initial considerations, the document first describes a generic
   architectural framework to setup automated benchmarking experiments.
   Second, the automation methodology is discussed, with a particular
   focus on experiment and procedure description approaches to support
   reproducibility of the automated benchmarks, a key challenge in VNF
   benchmarking.  Finally, two independent, open-source reference
   implementations are presented.  The document addresses state-of-the-
   art work on VNF benchmarking from scientific publications and current
   developments in other standardization bodies (e.g., [ETS14c] and
   [RFC8204]) wherever possible.








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2.  Terminology

   Common benchmarking terminology contained in this document is derived
   from [RFC1242].  Also, the reader is assumed to be familiar with the
   terminology as defined in the European Telecommunications Standards
   Institute (ETSI) NFV document [ETS14b].  Some of these terms, and
   others commonly used in this document, are defined below.

   NFV:  Network Function Virtualization - the principle of separating
      network functions from the hardware they run on by using virtual
      hardware abstraction.

   VNF:  Virtualized Network Function - a software-based network
      function.  A VNF can be either represented by a single entity or
      be composed by a set of smaller, interconnected software
      components, called VNF components (VNFCs) [ETS14d].  Those VNFs
      are also called composed VNFs.

   NS:  Network Service - a collection of interconnected VNFs forming a
      end-to-end service.  The interconnection is often done using
      chaining of functions based on a VNF-FG.

   VNF-FG:  Virtualized Network Function Forwarding Graph - an ordered
      list of VNFs or VNFCs creating a service chain.

   NFVI:  NFV Infrastructure - collection of NFVI PoPs under one
      orchestrator.

   NFVI PoP:  NFV Infrastructure Point of Presence - any combination of
      virtualized compute, storage, and network resources.

   VIM:  Virtualized Infrastructure Manager - functional block that is
      responsible for controlling and managing the NFVI compute,
      storage, and network resources, usually within one operator's
      Infrastructure Domain (e.g.  NFVI-PoP).

   VNFM:  Virtualized Network Function Manager - functional block that
      is responsible for controlling and managing the VNF life-cycle.

   NFVO:  NFV Orchestrator - functional block coordinates the management
      of network service (NS) life-cycles, VNF life-cycles (supported by
      the VNFM) and NFVI resources (supported by the VIM) to ensure an
      optimized allocation of the necessary resources and connectivity.

   VNFD:  Virtualised Network Function Descriptor - configuration
      template that describes a VNF in terms of its deployment and
      operational behaviour, and is used in the process of VNF on-
      boarding and managing the life cycle of a VNF instance.



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   VNFC:  Virtualized Network Function Component - a software component
      that implements (parts of) the VNF functionality.  A VNF can
      consist of a single VNFC or multiple, interconnected VNFCs
      [ETS14d]

3.  Scope

   This document assumes VNFs as black boxes when defining their
   benchmarking methodologies.  White box approaches are assumed and
   analysed as a particular case under the proper considerations of
   internal VNF instrumentation, later discussed in this document.

   This document outlines a methodology for VNF benchmarking,
   specifically addressing its automation.

4.  Considerations

   VNF benchmarking considerations are defined in [RFC8172].
   Additionally, VNF pre-deployment testing considerations are well
   explored in [ETS14c].

4.1.  VNF Testing Methods

   Following ETSI's model in [ETS14c], we distinguish three methods for
   VNF evaluation:

   Benchmarking:  Where parameters (e.g., CPU, memory, storage) are
      provided and the corresponding performance metrics (e.g., latency,
      throughput) are obtained.  Note, such evaluations might create
      multiple reports, for example, with minimal latency or maximum
      throughput results.

   Verification:  Both parameters and performance metrics are provided
      and a stimulus verifies if the given association is correct or
      not.

   Dimensioning:  Performance metrics are provided and the corresponding
      parameters obtained.  Note, multiple deployments may be required,
      or if possible, underlying allocated resources need to be
      dynamically altered.

   Note: Verification and Dimensioning can be reduced to Benchmarking.
   Therefore, we focus on Benchmarking in the rest of the document.








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4.2.  Benchmarking Procedures

   VNF benchmarking procedures contain multiple aspects that may or may
   not be automated:

   Orchestration:   Placement (assignment/allocation of resources) and
      interconnection (physical/virtual) of network function(s) and
      benchmark components (e.g., OpenStack/Kubernetes templates, NFV
      description solutions, like OSM/ONAP).

   Configuration:   Benchmark components and VNFs are configured to
      execute the test settings (e.g., populate routing table, load PCAP
      source files in source of stimulus).

   Execution:   Experiments run repeatedly according to configuration
      and orchestrated components for each VNF benchmarking test case.

   Output:   There might be generic VNF footprint metrics (e.g., CPU and
      memory consumption) and specific VNF traffic processing metrics
      (e.g., transactions or throughput), which can be parsed and
      processed in generic or specific ways (e.g., by statistics or
      machine learning algorithms).

   For the purposes of dissecting the automated execution procedures,
   consider the following definitions:

   Trial:   is a single process or iteration to obtain VNF benchmarking
      metrics from measurement.  A Benchmarking Test should always run
      multiple Trails to get statistical confidence about the obtained
      measurements.

   Test:   Defines parameters, e.g., configurations, resource
      assignment, for benchmarked components to perform one or multiple
      trials.  Each Trial must be executed following a particular
      deployment scenario composed by a Method.  Proper measures must be
      taken to ensure statistic validity (e.g., independence across
      trials of generated load patterns).

   Method:   Consists of one or more Tests to benchmark a VNF.  A Method
      can explicitly list ranges of parameter values for the
      configuration of benchmarking components.  Each value of such a
      range is to be realized in a Test.  I.e., Methods can define
      parameter studies.








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5.  A Generic VNF Benchmarking Architectural Framework

   A generic VNF benchmarking architectural framework, shown in
   Figure 1, establishes the disposal of essential components and
   control interfaces, explained below, that enable the automation of
   VNF benchmarking methodologies.


                              +---------------+
                              |    Manager    |
                Control       | (Coordinator) |
                Interface     +---+-------+---+
             +--------+-----------+       +-------------------+
             |        |                                       |
             |        |   +-------------------------+         |
             |        |   |    System Under Test    |         |
             |        |   |                         |         |
             |        |   |    +-----------------+  |         |
             |     +--+------- +       VNF       |  |         |
             |     |           |                 |  |         |
             |     |           | +----+   +----+ |  |         |
             |     |           | |VNFC|...|VNFC| |  |         |
             |     |           | +----+   +----+ |  |         |
             |     |           +----.---------.--+  |         |
       +-----+---+ |  Monitor  |    :         :     |   +-----+----+
       | Agent   | |{listeners}|----^---------V--+  |   |  Agent   |
       |(Sender) | |           |    Execution    |  |   |(Receiver)|
       |         | |           |   Environment   |  |   |          |
       |{Probers}| +-----------|                 |  |   |{Probers} |
       +-----.---+        |    +----.---------.--+  |   +-----.----+
             :            +---------^---------V-----+         :
             V                      :         :               :
             :................>.....:         :............>..:
             Stimulus Traffic Flow


                 Figure 1: Generic VNF Benchmarking Setup

   Agent --  executes active stimulus using probers, i.e., benchmarking
      tools, to benchmark and collect network and system performance
      metrics.  A single Agent can perform localized benchmarks in
      execution environments (e.g., stress tests on CPU, memory, disk I/
      O) or can generate stimulus traffic and the other end be the VNF
      itself where, for example, one-way latency is evaluated.  The
      interaction among distributed Agents enable the generation and
      collection of end-to-end metrics (e.g., frame loss rate, latency)
      measured from stimulus traffic flowing through a VNF.  An Agent
      can be defined by a physical or virtual network function.  In



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      addition, Agent must expose to Manager its available Probers and
      execution environment capabilities.



      Prober --  defines an abstraction layer for a software or hardware
         tool able to generate stimulus traffic to a VNF or perform
         stress tests on execution environments.  Probers might be
         specific or generic to an execution environment or a VNF.  For
         an Agent, a Prober must provide programmable interfaces for its
         life cycle management workflows, e.g., configuration of
         operational parameters, execution of stilumus, parsing of
         extracted metrics, and debugging options.  Specific Probers
         might be developed to abstract and to realize the description
         of particular benchmarking methodologies.

   Monitor --  when possible is instantiated inside the System Under
      Test, VNF and/or NFVI PoP (e.g., as a plug-in process in a
      virtualized environment), to perform the passive monitoring, using
      Listeners, for the extraction of metrics while Agents` stimuli
      takes place.  Monitors observe particular properties according to
      NFVI PoPs and VNFs capabilities, i.e., exposed passive monitoring
      interfaces.  Multiple Listeners can be executed at once in
      synchrony with a Prober' stimulus on a SUT.  A Monitor can be
      defined as a virtual network function.  In addition, Monitor must
      expose to Manager its available Listeners and execution
      environment capabilities.



      Listener --  defines one or more software interfaces for the
         extraction of particular metrics monitored in a target VNF and/
         or execution environment.  A Listener must provide programmable
         interfaces for its life cycle management workflows, e.g.,
         configuration of operational parameters, execution of passive
         monitoring captures, parsing of extracted metrics, and
         debugging options.  White-box benchmarking approaches must be
         carefully analyzed, as varied methods of passive performance
         monitoring might be implemented as a Listener, possibly
         impacting the VNF and/or execution environment performance
         results.

   Manager --  performs (i) the discovery of available Agents/Monitors
      and their respective features (i.e., available Probers/Listeners
      and execution environment capabilities), (ii) the coordination and
      synchronization of activities of Agents and Monitors to perform a
      benchmark test, (iii) the collection, processing and aggregation
      of all VNF benchmarking results that correlates the VNF stimuli



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      and the, possible, SUT monitored metrics.  A Manager executes the
      main configuration, operation, and management actions to deliver
      the VNF benchmarking results.  A Manager can be defined as a
      physical or virtual network function.

   Virtualized Network Function (VNF) --  consists of one or more
      software components, so called VNF components (VNFC), adequate for
      performing a network function according to allocated virtual
      resources and satisfied requirements in an execution environment.
      A VNF can demand particular configurations for benchmarking
      specifications, demonstrating variable performance based on
      available virtual resources/parameters and configured enhancements
      targeting specific technologies (e.g., NUMA, SR-IOV, CPU-Pinning).

   Execution Environment --  defines a virtualized and controlled
      composition of capabilities necessary for the execution of a VNF.
      An execution environment stands as a general purpose level of
      virtualization with abstracted resources available for one or more
      VNFs.  It can also define specific technology habilitation,
      incurring in viable settings for enhancing the performance of
      VNFs.

5.1.  Deployment Scenarios

   A deployment scenario realizes the instantiation of physical and/or
   virtual of components of a Generic VNF Benchmarking Architectural
   Framework needed to habilitate the execution of an automated VNF
   benchmarking methodology.

   The following considerations hold for deployment scenarios:

   o  Not all components are mandatory, possible to be disposed in
      varied settings.

   o  Components can be composed in a single entity and be defined as
      black or white boxes.  For instance, Manager and Agents could
      jointly define one hardware/software entity to perform a VNF
      benchmark and present results.

   o  Monitor is not a mandatory component and must be considered only
      when performed white box benchmarking approaches for a VNF and/or
      its execution environment.

   o  Monitor can be defined by multiple instances of software
      components, each addressing a VNF or execution environment and
      their respective open interfaces for the extraction of metrics.





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   o  Agents can be disposed in varied topology setups, included the
      possibility of multiple input and output ports of a VNF being
      directly connected each in one Agent.

   o  All benchmarking components defined in a deployment scenario must
      perform the synchronization of clocks.

6.  Methodology

   Portability is an intrinsic characteristic of VNFs and allows them to
   be deployed in multiple environments.  This enables various
   benchmarking setups in varied deployment scenarios.  A VNF
   benchmarking methodology must be described in a clear and objective
   manner in order to allow effective repeatability and comparability of
   the test results.  Those results, the outcome of a VNF benchmarking
   process, must be captured in a VNF Benchmarking Report (VNF-BR), as
   shown in Figure 2.



                                        ______________
               +--------+              |              |
               |        |              |  Automated   |
               | VNF-BD |--(defines)-->| Benchmarking |
               |        |              |   Process    |
               +--------+              |______________|
                                              V
                                              |
                                         (generates)
                                              |
                                              v
                                 +-------------------------+
                                 |         VNF-BR          |
                                 | +--------+   +--------+ |
                                 | |        |   |        | |
                                 | | VNF-BD |   | VNF-PP | |
                                 | | {copy} |   |        | |
                                 | +--------+   +--------+ |
                                 +-------------------------+

           Figure 2: VNF benchmarking process inputs and outputs

   A VNF Benchmarking Report consist of two parts:

   VNF Benchmarking Descriptor (VNF-BD) --   contains all required
      definitions and requirements to deploy, configure, execute, and
      reproduce VNF benchmarking tests.  VNF-BDs are defined by the
      developer of a benchmarking methodology and serve as input to the



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      benchmarking process, before being included in the generated VNF-
      BR.

   VNF Performance Profile (VNF-PP) --   contains all measured metrics
      resulting from the execution of a benchmarking.  Additionally, it
      might also contain additional recordings of configuration
      parameters used during the execution of the benchmarking scenario
      to facilitate comparability of VNF-BRs.

   A VNF-BR correlates structural and functional parameters of VNF-BD
   with extracted VNF benchmarking metrics of the obtained VNF-PP.  The
   content of each part of a VNF-BR is described in the following
   sections.

6.1.  VNF Benchmarking Descriptor (VNF-BD)

   VNF Benchmarking Descriptor (VNF-BD) -- an artifact that specifies a
   method of how to measure a VNF Performance Profile.  The
   specification includes structural and functional instructions and
   variable parameters at different abstraction levels (e.g., topology
   of the deployment scenario, benchmarking target metrics, parameters
   of benchmarking components).  VNF-BD may be specific to a VNF or
   applicable to several VNF types.  A VNF-BD can be used to elaborate a
   VNF benchmark deployment scenario aiming at the extraction of
   particular VNF performance metrics.

   The following items define the VNF-BD contents.

6.1.1.  Descriptor Headers

   The definition of parameters concerning the descriptor file, e.g.,
   its version, identidier, name, author and description.

6.1.2.  Target Information

   General information addressing the target VNF(s) the VNF-BD is
   applicable, with references to any specific characteristics, i.e.,
   the VNF type, model, version/release, author, vendor, architectural
   components, among any other particular features.

6.1.3.  Deployment Scenario

   This section contains all information needed to describe the
   deployment of all involved functional components mandatory for the
   execution of the benchmarking tests addressed by the VNF-BD.






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6.1.3.1.  Topology

   Information about the experiment topology, concerning the disposition
   of the components in a benchmarking setup (see Section 5).  It must
   define the type of each component and how they are interconnected
   (i.e., interface, link and network characteristics).  Acceptable
   topology descriptors might include references to external
   configuration files particular of orchestration technologies (e.g.,
   TOSCA, YANG).

6.1.3.2.  Requirements

   Involves the definition of execution environment requirements for the
   tests.  Therefore, they concern all required capabilities needed for
   the execution of the target VNF and the other components composing
   the benchmarking setup.  Examples of requirements include the
   allocation of CPUs, memory and disk for each component in the
   deployment scenario.

6.1.3.3.  Policies

   Involves the definition of execution environment policies to run the
   tests.  Policies might specify the (anti)-affinity placement rules
   for each component in the topology, min/max allocation of resources,
   specific enabling technologies (e.g., DPDK, SR-IOV, PCIE) needed for
   each component.

6.1.4.  Settings

   Involves any specific configuration of benchmarking components in a
   setup described the the deployment scenario topology.

6.1.4.1.  Components

   Specifies the details of each component in the described topology in
   the deployment scenario.  For instante, it contains the role of each
   component and its particular parameters, as the cases detailed below:

   VNF Configurations:   Defines any specific configuration that must be
      loaded into the VNF to execute the benchmarking experiments (e.g.,
      routing table, firewall rules, subscribers profile).

   Agents:   Defines the configured toolset of probers and related
      benchmarking/active metrics, available workloads, traffic formats/
      traces, and configurations to enable hardware capabilities (if
      existent).  In addition, it defines metrics from each prober to be
      extracted when running the benchmarking tests.




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   Monitors:   defines the configured toolset of listeners and related
      monitoring/passive metrics, configuration of the interfaces with
      the monitoring target (VNF and/or execution environment), and
      configurations to enable specific hardware capabilities (if
      existent).  In addition, it defines metrics from each listener to
      be extracted when running the benchmarking tests.

6.1.4.2.  Environment

   The definition of parameters concerning the execution environment of
   the VNF-BD, for instance, containing name, description, plugin/
   driver, and parameters to realize the interface with an orchestration
   component responsible to instantiate each VNF-BD deployment scenario.

6.1.4.3.  Procedures Configuration

   The definition of parameters concerning the execution of the
   benchmarking procedures, for instance, containing the number of
   repetitions for each trial, test, and the whole VNF-BD (method).

6.2.  VNF Performance Profile (VNF-PP)

   VNF Performance Profile (VNF-PP) -- defines a mapping between
   resources allocated to a VNF (e.g., CPU, memory) as well as assigned
   configurations (e.g., routing table used by the VNF) and the VNF
   performance metrics (e.g., throughput, latency, CPU, memory) obtained
   in a benchmarking test conducted using a VNF-BD.  Logically, packet
   processing metrics are presented in a specific format addressing
   statistical significance (e.g., median, standard deviation,
   percentiles) where a correspondence among VNF parameters and the
   delivery of a measured VNF performance exists.

   The following items define the VNF-PP contents.

6.2.1.  Execution Environment

   Execution environment information is has to be included in every VNF-
   PP and is required to describe the environment on which a benchmark
   test was actually executed.

   Ideally, any person who has a VNF-BD and its complementing VNF-PP
   with its execution environment information available, must be able to
   reproduce the same deployment scenario and VNF benchmarking tests to
   obtain identical VNF-PP measurement results.

   If not already defined by the VNF-BD deployment scenario requirements
   (Section 6.1.3), for each component in the deployment scenario of the
   VNF benchmarking setup, the following topics must be detailed:



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   Hardware Specs:   Contains any information associated with the
      underlying hardware capabilities offered and used by the component
      during the benchmarking tests.  Examples of such specification
      include allocated CPU architecture, connected NIC specs, allocated
      memory DIMM, etc.  In addition, any information concerning details
      of resource isolation must also be described in this part of the
      VNF-PP.

   Software Specs:   Contains any information associated with the
      software apparatus offered and used during the benchmarking tests.
      Examples include versions of operating systems, kernels,
      hypervisors, container image versions, etc.

   Optionally, a VNF-PP execution environment might contain references
   to an orchestration description document (e.g., HEAT template) to
   clarify technological aspects of the execution environment and any
   specific parameters that it might contain for the VNF-PP.

6.2.2.  Measurement Results

   Measurement results concern the extracted metrics, output of
   benchmarking procedures, classified into:

   VNF Processing/Active Metrics:   Concerns metrics explicitly defined
      by or extracted from direct interactions of Agents with a VNF.
      Those can be defined as generic metric related to network packet
      processing (e.g., throughput, latency) or metrics specific to a
      particular VNF (e.g., vIMS confirmed transactions, DNS replies).

   VNF Monitored/Passive Metrics:   Concerns the Monitors' metrics
      captured from a VNF execution, classified according to the
      virtualization level (e.g., baremetal, VM, container) and
      technology domain (e.g., related to CPU, memory, disk) from where
      they were obtained.

   Depending on the configuration of the benchmarking setup and the
   planned use cases for the resulting VNF-PPs, measurement results can
   be stored as raw data, e.g., time series data about CPU utilization
   of the VNF during a throughput benchmark.  In the case of VNFs
   composed of multiple VNFCs, those resulting data should be
   represented as vectors, capturing the behavior of each VNFC, if
   available from the used monitoring systems.  Alternatively, more
   compact representation formats can be used, e.g., statistical
   information about a series of latency measurements, including
   averages and standard deviations.  The exact output format to be used
   is defined in the complementing VNF-BD (Section 6.1).





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   The representation format of a VNF-PP must be easily translated to
   address the combined set of classified items in the 3x3 Matrix
   Coverage defined in [RFC8172].

6.3.  Procedures

   The methodology for VNF Benchmarking Automation encompasses the
   process defined in Figure 2, i.e., the procedures that translate a
   VNF-BD into a VNF-PP composing a VNF-BR by the means of the
   components specified in Figure 1.  This section details the sequence
   of events that realize such process.

6.3.1.  Pre-Execution

   Before the execution of benchmark tests, some procedures must be
   performed:

   1.   A VNF-BD must be defined to be later instantiated into a
      deployment scenario and executed its tests.  Such a description
      must contain all the structural and functional settings defined in
      Section 6.1.  At the end of this step, the complete method of
      benchmarking the target VNF is defined.

   2.   The environment needed for a VNF-BD must be defined to realize
      its deployment scenario, in an automated or manual method.  This
      step might count on the instantiation of orchestration platforms
      and the composition of specific topology descriptors needed by
      those platforms to realize the VNF-BD deployment scenario.  At the
      end of this step, the whole environment needed to instantiate the
      components of a VNF-BD deployment scenario is defined.

   3.   The VNF target image must be prepared to be benchmarked, having
      all its capabilities fully described.  In addition all the probers
      and listeners defined in the VNF-BD must be implemented to realize
      the benchmark tests.  At the end of this step, the complete set of
      components of the benchmarking VNF-BD deployment scenario is
      defined.

6.3.2.  Automated Execution

   Satisfied all the pre-execution procedures, the automated execution
   of the tests specified by the VNF-BD follow:

   1.   Upon the parsing of a VNF-BD, the Manager must detect the VNF-BD
      variable input field (e.g., list of resources values) and compose
      the all the permutations of parameters.  For each permutation, the
      Manager must elaborate a VNF-BD instance.  Each VNF-BD instance
      defines a test, and it will have its deployment scenario



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      instantiated accordingly.  I.e., the Manager must interface an
      orchestration platform to realize the automated instantiation of
      each deployment scenario defined by a VNF-BD instance (i.e., a
      test).  The Manager must iterate through all the VNF-BD instances
      to finish the whole set of tests defined by all the permutations
      of the VNF-BD input fields.

   2.   Given a VNF-BD instance, the Manager, using the VNF-BD
      environment settings, must interface an orchestrator platform
      requesting the deployment of a scenario to realize a test.  To
      perform such step, The Manager might interface a plugin/driver
      responsible to properly parse the deployment scenario
      specifications into the orchestration platform interface format.

   3.   An orchestration platform must deploy the scenario requested by
      the Manager, assuring the requirements and policies specified on
      it.  In addition, the orchestration platform must acknowledge the
      deployed scenario to the Manager specifying the management
      interfaces of the VNF and the other components in the running
      instances for the benchmarking test.

   4.   Agent(s) and Monitor(s) (if existing) and the target VNF must be
      configured by the Manager according to the components settings
      defined in the VNF-BD instance.  After this step, the whole VNF-BD
      test will be ready to be performed.

   5.   Manager must interface Agent(s) and Monitor(s) (if existing) via
      control interfaces to required the execution of the benchmark
      stimuli (and monitoring, if existing) and retrieve expected
      metrics captured during or at the end of each Trial.  I.e., for a
      single test, according to the VNF-BD execution settings, the
      Manager must guarantee that one or more trials realize the
      required measurements to characterize the performance behavior of
      a VNF.

   6.   Output measurements from each obtained benchmarking test, and
      its possible trials, must be collected by the Manager, until all
      tests be finished.  In the execution settings of the parsed VNF-
      BD, the Manager must check the method repetition, and perform the
      whole VNF-BD tests (i.e., since step 1), until all methods are
      finished.

   7.   Collected all measurements from the VNF-BD (trials, tests and
      methods) execution, the intended metrics, as described in the VNF-
      BD, must be parsed, extracted and combined to create the
      corresponding VNF-PP.  The combination of used VNF-BD and
      generated VNF-PP make up the resulting VNF benchmark report (VNF-
      BR).



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6.3.3.  Post-Execution

   After the process of a VNF-BD, generated the associated VNF-BR, some
   procedures must be guaranteed:

   1.   Perform a statistical analysis of the output VNF-BR.

   2.   Perform a machine learning based analysis of the output VNF-BR.

   3.   Research the analysis outputs to the detect any possible cause-
      effect factors and/or intrinsic correlations in the VNF-BR (e.g.,
      outliers).

   4.   Review the input VNF-BD and modify it to realize the proper
      extraction of the target VNF metrics based on the performed
      research Iterate in the previous steps until composing a stable
      and representative VNF-BR.

6.4.  Particular Cases

   As described in [RFC8172], VNF benchmarking might require to change
   and adapt existing benchmarking methodologies.  More specifically,
   the following cases need to be considered.

6.4.1.  Capacity

   VNFs are usually deployed inside containers or VMs to build an
   abstraction layer between physical resources and the resources
   available to the VNF.  According to [RFC8172], it may be more
   representative to design experiments in a way that the VMs hosting
   the VNFs are operating at maximum of 50% utilization and split the
   workload among several VMs, to mitigateside effects of overloaded
   VMs.  Those cases are supported by the presented automation
   methodologies through VNF-BDs that enable direct control over the
   resource assignments and topology layouts used for a benchmarking
   experiment.

6.4.2.  Isolation

   One of the main challenges of NFV is to create isolation between
   VNFs.  Benchmarking the quality of this isolation behavior can be
   achieved by Agents that take the role of a noisy neighbor, generating
   a particular workload in synchrony with a benchmarking procedure over
   a VNF.  Adjustments of the Agent's noisy workload, frequency,
   virtualization level, among others, must be detailed in the VNF- BD.






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6.4.3.  Failure Handling

   Hardware and software components will fail or have errors and thus
   trigger healing actions of the benchmarked VNFs (self-healing).
   Benchmarking procedures must also capture the dynamics of this VNF
   behavior, e.g., if a container or VM restarts because the VNF
   software crashed.  This results in offline periods that must be
   captured in the benchmarking reports, introducing additional metrics,
   e.g., max. time-to-heal.  The presented concept, with a flexible VNF-
   PP structure to record arbitrary metrics, enables automation of this
   case.

6.4.4.  Elasticity and Flexibility

   Having software based network functions and the possibility of a VNF
   to be composed by multiple components (VNFCs), internal events of the
   VNF might trigger changes in VNF behavior, e.g.,activating
   functionalities associated with elasticity such as automated scaling.
   These state changes and triggers (e.g. the VNF's scaling state) must
   be captured in the benchmarking results (VNF-PP) to provide a
   detailed characterization of the VNF's performance behavior in
   different states.

6.4.5.  Handling Configurations

   As described in [RFC8172], does the sheer number of test conditions
   and configuration combinations create a challenge for VNF
   benchmarking.  As suggested, machine readable output formats, as they
   are presented in this document, will allow automated benchmarking
   procedures to optimize the tested configurations.  Approaches for
   this are, e.g., machine learning-based configuration space sub-
   sampling methods, such as [Peu-c].

6.4.6.  White Box VNF

   A benchmarking setup must be able to define scenarios with and
   without monitoring components inside the VNFs and/or the hosting
   container or VM.  If no monitoring solution is available from within
   the VNFs, the benchmark is following the black-box concept.  If, in
   contrast, those additional sources of information from within the VNF
   are available, VNF-PPs must be able to handle these additional VNF
   performance metrics.

7.  Relevant Influencing Aspects

   In general, automated VNF benchmarking tests as herein described must
   capture relevant causes of performance variability.  Concerning a




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   deployment scenario, influencing aspects on the performance of a VNF
   can be observed in:

   Deployment Scenario Topology:  The disposition of components can
      define particular interconnections among them composing a specific
      case/method of VNF benchmarking.

   Execution Environment:  The availability of generic and specific
      capabilities satisfying VNF requirements define a skeleton of
      opportunities for the allocation of VNF resources.  In addition,
      particular cases can define multiple VNFs interacting in the same
      execution environment of a benchmarking setup.

   VNF:  A detailed description of functionalities performed by a VNF
      sets possible traffic forwarding and processing operations it can
      perform on packets, added to its running requirements and specific
      configurations, which might affect and compose a benchmarking
      setup.

   Agent:  The toolset available for the benchmarking stimulus of a VNF
      and its characteristics of packets format and workload can
      interfere in a benchmarking setup.  VNFs can support specific
      traffic format as stimulus.

   Monitor:  In a particular benchmarking setup where measurements of
      VNF and/or execution environment metrics are available for
      extraction, an important analysis consist in verifying if the
      Monitor components can impact performance metrics of the VNF and
      the underlying execution environment.

   Manager:  The overall composition of VNF benchmarking procedures can
      determine arrangements of internal states inside a VNF, which can
      interfere in observed benchmarking metrics.

   The listed influencing aspects must be carefully analyzed while
   automating a VNF benchmarking methodology.

8.  Open Source Reference Implementations

   There are two open source reference implementations that are build to
   automate benchmarking of Virtualized Network Functions (VNFs).

8.1.  Gym

   The software, named Gym, is a framework for automated benchmarking of
   Virtualized Network Functions (VNFs).  It was coded following the
   initial ideas presented in a 2015 scientific paper entitled "VBaaS:
   VNF Benchmark-as-a-Service" [Rosa-a].  Later, the evolved design and



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   prototyping ideas were presented at IETF/IRTF meetings seeking impact
   into NFVRG and BMWG.

   Gym was built to receive high-level test descriptors and execute them
   to extract VNFs profiles, containing measurements of performance
   metrics - especially to associate resources allocation (e.g., vCPU)
   with packet processing metrics (e.g., throughput) of VNFs.  From the
   original research ideas [Rosa-a], such output profiles might be used
   by orchestrator functions to perform VNF lifecycle tasks (e.g.,
   deployment, maintenance, tear-down).

   The proposed guiding principles, elaborated in [Rosa-b], to design
   and build Gym can be composed in multiple practical ways for
   different VNF testing purposes:

   o  Comparability: Output of tests shall be simple to understand and
      process, in a human-read able format, coherent, and easily
      reusable (e.g., inputs for analytic applications).

   o  Repeatability: Test setup shall be comprehensively defined through
      a flexible design model that can be interpreted and executed by
      the testing platform repeatedly but supporting customization.

   o  Configurability: Open interfaces and extensible messaging models
      shall be available between components for flexible composition of
      test descriptors and platform configurations.

   o  Interoperability: Tests shall be ported to different environments
      using lightweight components.

   In [Rosa-b] Gym was utilized to benchmark a decomposed IP Multimedia
   Subsystem VNF.  And in [Rosa-c], a virtual switch (Open vSwitch -
   OVS) was the target VNF of Gym for the analysis of VNF benchmarking
   automation.  Such articles validated Gym as a prominent open source
   reference implementation for VNF benchmarking tests.  Such articles
   set important contributions as discussion of the lessons learned and
   the overall NFV performance testing landscape, included automation.

   Gym stands as one open source reference implementation that realizes
   the VNF benchmarking methodologies presented in this document.  Gym
   is being released open source at [Gym].  The code repository includes
   also VNF Benchmarking Descriptor (VNF-BD) examples on the vIMS and
   OVS targets as described in [Rosa-b] and [Rosa-c].








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8.2.  tng-bench

   Another software that focuses on implementing a framework to
   benchmark VNFs is the "5GTANGO VNF/NS Benchmarking Framework" also
   called "tng-bench" (previously "son-profile") and was developed as
   part of the two European Union H2020 projects SONATA NFV and 5GTANGO
   [tango].  Its initial ideas were presented in [Peu-a] and the system
   design of the end-to-end prototype was presented in [Peu-b].

   Tng-bench aims to be a framework for the end-to-end automation of VNF
   benchmarking processes.  Its goal is to automate the benchmarking
   process in such a way that VNF-PPs can be generated without further
   human interaction.  This enables the integration of VNF benchmarking
   into continuous integration and continuous delivery (CI/CD) pipelines
   so that new VNF-PPs are generated on-the-fly for every new software
   version of a VNF.  Those automatically generated VNF-PPs can then be
   bundled with the VNFs and serve as inputs for orchestration systems,
   fitting to the original research ideas presented in [Rosa-a] and
   [Peu-a].

   Following the same high-level VNF testing purposes as Gym, namely:
   Comparability, repeatability, configurability, and interoperability,
   tng- bench specifically aims to explore description approaches for
   VNF benchmarking experiments.  In [Peu-b] a prototype specification
   for VNF-BDs is presented which not only allows to specify generic,
   abstract VNF benchmarking experiments, it also allows to describe
   sets of parameter configurations to be tested during the benchmarking
   process, allowing the system to automatically execute complex
   parameter studies on the SUT, e.g., testing a VNF's performance under
   different CPU, memory, or software configurations.

   Tng-bench was used to perform a set of initial benchmarking
   experiments using different VNFs, like a Squid proxy, an Nginx load
   balancer, and a Socat TCP relay in [Peu-b].  Those VNFs have not only
   been benchmarked in isolation, but also in combined setups in which
   up to three VNFs were chained one after each other.  These
   experiments were used to test tng-bench for scenarios in which
   composed VNFs, consisting of multiple VNF components (VNFCs), have to
   be benchmarked.  The presented results highlight the need to
   benchmark composed VNFs in end-to-end scenarios rather than only
   benchmark each individual component in isolation, to produce
   meaningful VNF- PPs for the complete VNF.

   Tng-bench is actively developed and released as open source tool
   under Apache 2.0 license [tng-bench].






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9.  Security Considerations

   Benchmarking tests described in this document are limited to the
   performance characterization of VNFs in a lab environment with
   isolated network.

   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.

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

10.  IANA Considerations

   This document does not require any IANA actions.

11.  Acknowledgement

   The authors would like to thank the support of Ericsson Research,
   Brazil.  Parts of this work have received funding from the European
   Union's Horizon 2020 research and innovation programme under grant
   agreement No.  H2020-ICT-2016-2 761493 (5GTANGO: https://5gtango.eu).

12.  References

12.1.  Normative References

   [ETS14a]   ETSI, "Architectural Framework - ETSI GS NFV 002 V1.2.1",
              Dec 2014, <http://www.etsi.org/deliver/etsi\_gs/
              NFV/001\_099/002/01.02.01-\_60/gs\_NFV002v010201p.pdf>.

   [ETS14b]   ETSI, "Terminology for Main Concepts in NFV - ETSI GS NFV
              003 V1.2.1", Dec 2014,
              <http://www.etsi.org/deliver/etsi_gs/NFV/001_099-
              /003/01.02.01_60/gs_NFV003v010201p.pdf>.

   [ETS14c]   ETSI, "NFV Pre-deployment Testing - ETSI GS NFV TST001
              V1.1.1", April 2016,
              <http://docbox.etsi.org/ISG/NFV/Open/DRAFTS/TST001_-_Pre-
              deployment_Validation/NFV-TST001v0015.zip>.






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   [ETS14d]   ETSI, "Network Functions Virtualisation (NFV); Virtual
              Network Functions Architecture - ETSI GS NFV SWA001
              V1.1.1", December 2014,
              <https://docbox.etsi.org/ISG/NFV/Open/Publications_pdf/
              Specs-Reports/NFV-SWA%20001v1.1.1%20-%20GS%20-%20Virtual%2
              0Network%20Function%20Architecture.pdf>.

   [ETS14e]   ETSI, "Report on CI/CD and Devops - ETSI GS NFV TST006
              V0.0.9", April 2018,
              <https://docbox.etsi.org/isg/nfv/open/drafts/
              TST006_CICD_and_Devops_report>.

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

   [RFC8172]  A. Morton, "Considerations for Benchmarking Virtual
              Network Functions and Their Infrastructure", July 2017,
              <https://www.rfc-editor.org/info/rfc8172>.

   [RFC8204]  M. Tahhan, B. O'Mahony, A. Morton, "Benchmarking Virtual
              Switches in the Open Platform for NFV (OPNFV)", September
              2017, <https://www.rfc-editor.org/info/rfc8204>.

12.2.  Informative References

   [Gym]      "Gym Home Page", <https://github.com/intrig-unicamp/gym>.

   [Peu-a]    M. Peuster, H. Karl, "Understand Your Chains: Towards
              Performance Profile-based Network Service Management",
              Fifth European Workshop on Software Defined Networks
              (EWSDN) , 2016,
              <http://ieeexplore.ieee.org/document/7956044/>.

   [Peu-b]    M. Peuster, H. Karl, "Profile Your Chains, Not Functions:
              Automated Network Service Profiling in DevOps
              Environments", IEEE Conference on Network Function
              Virtualization and Software Defined Networks (NFV-SDN) ,
              2017, <http://ieeexplore.ieee.org/document/8169826/>.

   [Peu-c]    M. Peuster, H. Karl, "Understand your chains and keep your
              deadlines: Introducing time-constrained profiling for
              NFV", IEEE/IFIP 14th International Conference on Network
              and Service Management (CNSM) , 2018,
              <https://ris.uni-paderborn.de/record/6016>.






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   [Rosa-a]   R. V. Rosa, C. E. Rothenberg, R. Szabo, "VBaaS: VNF
              Benchmark-as-a-Service", Fourth European Workshop on
              Software Defined Networks , Sept 2015,
              <http://ieeexplore.ieee.org/document/7313620>.

   [Rosa-b]   R. Rosa, C. Bertoldo, C. Rothenberg, "Take your VNF to the
              Gym: A Testing Framework for Automated NFV Performance
              Benchmarking", IEEE Communications Magazine Testing
              Series , Sept 2017,
              <http://ieeexplore.ieee.org/document/8030496>.

   [Rosa-c]   R. V. Rosa, C. E. Rothenberg, "Taking Open vSwitch to the
              Gym: An Automated Benchmarking Approach", IV Workshop pre-
              IETF/IRTF, CSBC Brazil, July 2017,
              <https://intrig.dca.fee.unicamp.br/wp-
              content/plugins/papercite/pdf/rosa2017taking.pdf>.

   [tango]    "5GTANGO: Development and validation platform for global
              industry-specific network services and apps",
              <https://5gtango.eu>.

   [tng-bench]
              "5GTANGO VNF/NS Benchmarking Framework",
              <https://github.com/sonata-nfv/tng-sdk-benchmark>.

Authors' Addresses

   Raphael Vicente Rosa (editor)
   University of Campinas
   Av. Albert Einstein, 400
   Campinas, Sao Paulo  13083-852
   Brazil

   Email: rvrosa@dca.fee.unicamp.br
   URI:   https://intrig.dca.fee.unicamp.br/raphaelvrosa/


   Christian Esteve Rothenberg
   University of Campinas
   Av. Albert Einstein, 400
   Campinas, Sao Paulo  13083-852
   Brazil

   Email: chesteve@dca.fee.unicamp.br
   URI:   http://www.dca.fee.unicamp.br/~chesteve/






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   Manuel Peuster
   Paderborn University
   Warburgerstr. 100
   Paderborn  33098
   Germany

   Email: manuel.peuster@upb.de
   URI:   http://go.upb.de/peuster


   Holger Karl
   Paderborn University
   Warburgerstr. 100
   Paderborn  33098
   Germany

   Email: holger.karl@upb.de
   URI:   https://cs.uni-paderborn.de/cn/

































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