Internet Engineering Task Force (IETF)                  V. Bhuvaneswaran
Request for Comments: 8456                                      A. Basil
Category: Informational                               Veryx Technologies
ISSN: 2070-1721                                             M. Tassinari
                                             Hewlett Packard Enterprise
                                                              V. Manral
                                                                NanoSec
                                                               S. Banks
                                                         VSS Monitoring
                                                           October 2018


    Benchmarking Methodology for Software-Defined Networking (SDN)
                        Controller Performance

Abstract

  This document defines methodologies for benchmarking the control-
  plane performance of Software-Defined Networking (SDN) Controllers.
  The SDN Controller is a core component in the SDN architecture that
  controls the behavior of the network.  SDN Controllers have been
  implemented with many varying designs in order to achieve their
  intended network functionality.  Hence, the authors of this document
  have taken the approach of considering an SDN Controller to be a
  black box, defining the methodology in a manner that is agnostic to
  protocols and network services supported by controllers.  This
  document provides a method for measuring the performance of all
  controller implementations.

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
  https://www.rfc-editor.org/info/rfc8456.







Bhuvaneswaran, et al.         Informational                     [Page 1]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


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
  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 ....................................................4
     1.1. Conventions Used in This Document ..........................4
  2. Scope ...........................................................4
  3. Test Setup ......................................................4
     3.1. Test Setup - Controller Operating in Standalone Mode .......5
     3.2. Test Setup - Controller Operating in Cluster Mode ..........6
  4. Test Considerations .............................................7
     4.1. Network Topology ...........................................7
     4.2. Test Traffic ...............................................7
     4.3. Test Emulator Requirements .................................7
     4.4. Connection Setup ...........................................8
     4.5. Measurement Point Specification and Recommendation .........9
     4.6. Connectivity Recommendation ................................9
     4.7. Test Repeatability .........................................9
     4.8. Test Reporting .............................................9
  5. Benchmarking Tests .............................................11
     5.1. Performance ...............................................11
          5.1.1. Network Topology Discovery Time ....................11
          5.1.2. Asynchronous Message Processing Time ...............13
          5.1.3. Asynchronous Message Processing Rate ...............14
          5.1.4. Reactive Path Provisioning Time ....................17
          5.1.5. Proactive Path Provisioning Time ...................19
          5.1.6. Reactive Path Provisioning Rate ....................21
          5.1.7. Proactive Path Provisioning Rate ...................23
          5.1.8. Network Topology Change Detection Time .............25
     5.2. Scalability ...............................................26
          5.2.1. Control Sessions Capacity ..........................26
          5.2.2. Network Discovery Size .............................27
          5.2.3. Forwarding Table Capacity ..........................29





Bhuvaneswaran, et al.         Informational                     [Page 2]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     5.3. Security ..................................................31
          5.3.1. Exception Handling .................................31
          5.3.2. Handling Denial-of-Service Attacks .................32
     5.4. Reliability ...............................................34
          5.4.1. Controller Failover Time ...........................34
          5.4.2. Network Re-provisioning Time .......................36
  6. IANA Considerations ............................................37
  7. Security Considerations ........................................38
  8. References .....................................................38
     8.1. Normative References ......................................38
     8.2. Informative References ....................................38
  Appendix A. Benchmarking Methodology Using OpenFlow Controllers ...39
    A.1. Protocol Overview ..........................................39
    A.2. Messages Overview ..........................................39
    A.3. Connection Overview ........................................39
    A.4. Performance Benchmarking Tests .............................40
      A.4.1. Network Topology Discovery Time ........................40
      A.4.2. Asynchronous Message Processing Time ...................42
      A.4.3. Asynchronous Message Processing Rate ...................43
      A.4.4. Reactive Path Provisioning Time ........................44
      A.4.5. Proactive Path Provisioning Time .......................46
      A.4.6. Reactive Path Provisioning Rate ........................47
      A.4.7. Proactive Path Provisioning Rate .......................49
      A.4.8. Network Topology Change Detection Time .................50
    A.5. Scalability ................................................51
      A.5.1. Control Sessions Capacity ..............................51
      A.5.2. Network Discovery Size .................................52
      A.5.3. Forwarding Table Capacity ..............................54
    A.6. Security ...................................................55
      A.6.1. Exception Handling .....................................55
      A.6.2. Handling Denial-of-Service Attacks .....................57
    A.7. Reliability ................................................59
      A.7.1. Controller Failover Time ...............................59
      A.7.2. Network Re-provisioning Time ...........................61
  Acknowledgments ...................................................63
  Authors' Addresses ................................................64















Bhuvaneswaran, et al.         Informational                     [Page 3]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


1.  Introduction

  This document provides generic methodologies for benchmarking
  Software-Defined Networking (SDN) Controller performance.  To achieve
  the desired functionality, an SDN Controller may support many
  northbound and southbound protocols, implement a wide range of
  applications, and work either alone or as part of a group.  This
  document considers an SDN Controller to be a black box, regardless of
  design and implementation.  The tests defined in this document can be
  used to benchmark an SDN Controller for performance, scalability,
  reliability, and security, independently of northbound and southbound
  protocols.  Terminology related to benchmarking SDN Controllers is
  described in the companion terminology document [RFC8455].  These
  tests can be performed on an SDN Controller running as a virtual
  machine (VM) instance or on a bare metal server.  This document is
  intended for those who want to measure an SDN Controller's
  performance as well as compare the performance of various SDN
  Controllers.

1.1.  Conventions Used in This Document

  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.

2.  Scope

  This document defines a methodology for measuring the networking
  metrics of SDN Controllers.  For the purpose of this memo, the SDN
  Controller is a function that manages and controls Network Devices.
  Any SDN Controller without a control capability is out of scope for
  this memo.  The tests defined in this document enable the
  benchmarking of SDN Controllers in two ways: standalone mode
  (a standalone controller) and cluster mode (a cluster of homogeneous
  controllers).  These tests are recommended for execution in lab
  environments rather than in live network deployments.  Performance
  benchmarking of a federation of controllers (i.e., a set of SDN
  Controllers) managing different domains, is beyond the scope of this
  document.

3.  Test Setup

  As noted above, the tests defined in this document enable the
  measurement of an SDN Controller's performance in standalone mode and
  cluster mode.  This section defines common reference topologies that
  are referred to in individual tests described later in this document.



Bhuvaneswaran, et al.         Informational                     [Page 4]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


3.1.  Test Setup - Controller Operating in Standalone Mode

     +-----------------------------------------------------------+
     |               Application-Plane Test Emulator             |
     |                                                           |
     |        +-----------------+      +-------------+           |
     |        |   Application   |      |   Service   |           |
     |        +-----------------+      +-------------+           |
     |                                                           |
     +-----------------------------+(I2)-------------------------+
                                   |
                                   | (Northbound Interface)
                  +-------------------------------+
                  |       +----------------+      |
                  |       | SDN Controller |      |
                  |       +----------------+      |
                  |                               |
                  |    Device Under Test (DUT)    |
                  +-------------------------------+
                                   | (Southbound Interface)
                                   |
     +-----------------------------+(I1)-------------------------+
     |                                                           |
     |             +-----------+     +-------------+             |
     |             |  Network  |     |   Network   |             |
     |             | Device 2  |--..-| Device n - 1|             |
     |             +-----------+     +-------------+             |
     |                     /    \   /    \                       |
     |                    /      \ /      \                      |
     |                l0 /        X        \ ln                  |
     |                  /        / \        \                    |
     |               +-----------+  +-----------+                |
     |               |  Network  |  |  Network  |                |
     |               |  Device 1 |..|  Device n |                |
     |               +-----------+  +-----------+                |
     |                     |              |                      |
     |           +---------------+  +---------------+            |
     |           | Test Traffic  |  | Test Traffic  |            |
     |           |  Generator    |  |  Generator    |            |
     |           |    (TP1)      |  |    (TP2)      |            |
     |           +---------------+  +---------------+            |
     |                                                           |
     |              Forwarding-Plane Test Emulator               |
     +-----------------------------------------------------------+

                                Figure 1





Bhuvaneswaran, et al.         Informational                     [Page 5]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


3.2.  Test Setup - Controller Operating in Cluster Mode

     +-----------------------------------------------------------+
     |               Application-Plane Test Emulator             |
     |                                                           |
     |        +-----------------+      +-------------+           |
     |        |   Application   |      |   Service   |           |
     |        +-----------------+      +-------------+           |
     |                                                           |
     +-----------------------------+(I2)-------------------------+
                                   |
                                   | (Northbound Interface)
      +---------------------------------------------------------+
      |                                                         |
      | +------------------+           +------------------+     |
      | | SDN Controller 1 | <--E/W--> | SDN Controller n |     |
      | +------------------+           +------------------+     |
      |                                                         |
      |                    Device Under Test (DUT)              |
      +---------------------------------------------------------+
                                   | (Southbound Interface)
                                   |
     +-----------------------------+(I1)-------------------------+
     |                                                           |
     |             +-----------+     +-------------+             |
     |             |  Network  |     |   Network   |             |
     |             | Device 2  |--..-| Device n - 1|             |
     |             +-----------+     +-------------+             |
     |                     /    \   /    \                       |
     |                    /      \ /      \                      |
     |                l0 /        X        \ ln                  |
     |                  /        / \        \                    |
     |               +-----------+  +-----------+                |
     |               |  Network  |  |  Network  |                |
     |               |  Device 1 |..|  Device n |                |
     |               +-----------+  +-----------+                |
     |                     |              |                      |
     |           +---------------+  +---------------+            |
     |           | Test Traffic  |  | Test Traffic  |            |
     |           |  Generator    |  |  Generator    |            |
     |           |    (TP1)      |  |    (TP2)      |            |
     |           +---------------+  +---------------+            |
     |                                                           |
     |              Forwarding-Plane Test Emulator               |
     +-----------------------------------------------------------+

                                Figure 2




Bhuvaneswaran, et al.         Informational                     [Page 6]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


4.  Test Considerations

4.1.  Network Topology

  The test cases SHOULD use Leaf-Spine topology with at least two
  Network Devices in the topology for benchmarking.  Test traffic
  generators TP1 and TP2 SHOULD be connected to the leaf Network
  Device 1 and the leaf Network Device n.  To achieve a complete
  performance characterization of the SDN Controller, it is recommended
  that the controller be benchmarked for many network topologies and a
  varying number of Network Devices.  Further, care should be taken to
  make sure that a loop-prevention mechanism is enabled in either the
  SDN Controller or the network when the topology contains redundant
  network paths.

4.2.  Test Traffic

  Test traffic is used to notify the controller about the asynchronous
  arrival of new flows.  The test cases SHOULD use frame sizes of 128,
  512, and 1508 bytes for benchmarking.  Tests using jumbo frames are
  optional.

4.3.  Test Emulator Requirements

  The test emulator SHOULD timestamp the transmitted and received
  control messages to/from the controller on the established network
  connections.  The test cases use these values to compute the
  controller processing time.























Bhuvaneswaran, et al.         Informational                     [Page 7]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


4.4.  Connection Setup

  There may be controller implementations that support unencrypted and
  encrypted network connections with Network Devices.  Further, the
  controller may be backward compatible with Network Devices running
  older versions of southbound protocols.  It may be useful to measure
  the controller's performance with one or more applicable connection
  setup methods defined below.  For cases with encrypted communications
  between the controller and the switch, key management and key
  exchange MUST take place before any performance or benchmark
  measurements.

     1. Unencrypted connection with Network Devices, running the same
        protocol version.

     2. Unencrypted connection with Network Devices, running different
        protocol versions.

        Examples:

           a. Controller running current protocol version and switch
              running older protocol version.

           b. Controller running older protocol version and switch
              running current protocol version.

     3. Encrypted connection with Network Devices, running the same
        protocol version.

     4. Encrypted connection with Network Devices, running different
        protocol versions.

        Examples:

           a. Controller running current protocol version and switch
              running older protocol version.

           b. Controller running older protocol version and switch
              running current protocol version.












Bhuvaneswaran, et al.         Informational                     [Page 8]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


4.5.  Measurement Point Specification and Recommendation

  The accuracy of the measurements depends on several factors,
  including the point of observation where the indications are
  captured.  For example, the notification can be observed at the
  controller or test emulator.  The test operator SHOULD make the
  observations/measurements at the interfaces of the test emulator,
  unless explicitly specified otherwise in the individual test.  In any
  case, the locations of measurement points MUST be reported.

4.6.  Connectivity Recommendation

  The SDN Controller in the test setup SHOULD be connected directly
  with the forwarding-plane and management-plane test emulators to
  avoid any delays or failure introduced by the intermediate devices
  during benchmarking tests.  When the controller is implemented as a
  virtual machine, details of the physical and logical connectivity
  MUST be reported.

4.7.  Test Repeatability

  To increase confidence in the measured results, it is recommended
  that each test SHOULD be repeated a minimum of 10 times.

4.8.  Test Reporting

  Each test has a reporting format that contains some global and
  identical reporting components, and some individual components that
  are specific to individual tests.  The following parameters for test
  configuration and controller settings MUST be reflected in the test
  report.

  Test Configuration Parameters:

     1.  Controller name and version

     2.  Northbound protocols and versions

     3.  Southbound protocols and versions

     4.  Controller redundancy mode (standalone or cluster mode)

     5.  Connection setup (unencrypted or encrypted)

     6.  Network Device type (physical, virtual, or emulated)

     7.  Number of nodes




Bhuvaneswaran, et al.         Informational                     [Page 9]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     8.  Number of links

     9.  Data-plane test traffic type

     10. Controller system configuration (e.g., physical or virtual
         machine, CPU, memory, caches, operating system, interface
         speed, storage)

     11. Reference test setup (e.g., the setup shown in Section 3.1)

  Parameters for Controller Settings:

     1. Topology rediscovery timeout

     2. Controller redundancy mode (e.g., active-standby)

     3. Controller state persistence enabled/disabled

  To ensure the repeatability of the test, the following capabilities
  of the test emulator SHOULD be reported:

     1. Maximum number of Network Devices that the forwarding plane
        emulates

     2. Control message processing time (e.g., topology discovery
        messages)

  One way to determine the above two values is to simulate the required
  control sessions and messages from the control plane.






















Bhuvaneswaran, et al.         Informational                    [Page 10]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.  Benchmarking Tests

5.1.  Performance

5.1.1.  Network Topology Discovery Time

  Objective:

     Measure the time taken by the controller(s) to determine the
     complete network topology, defined as the interval starting with
     the first discovery message from the controller(s) at its
     southbound interface and ending with all features of the static
     topology determined.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST support network discovery.

     2. The tester should be able to retrieve the discovered topology
        information through either the controller's management
        interface or northbound interface to determine if the discovery
        was successful and complete.

     3. Ensure that the controller's topology rediscovery timeout has
        been set to the maximum value, to avoid initiation of the
        rediscovery process in the middle of the test.

  Procedure:

     1. Ensure that the controller is operational and that its network
        applications, northbound interface, and southbound interface
        are up and running.

     2. Establish the network connections between the controller and
        the Network Devices.

     3. Record the time for the first discovery message (Tm1) received
        from the controller at the forwarding-plane test emulator
        interface (I1).







Bhuvaneswaran, et al.         Informational                    [Page 11]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     4. Query the controller every t seconds (the RECOMMENDED value for
        t is 3) to obtain the discovered network topology information
        through the northbound interface or the management interface,
        and compare it with the deployed network topology information.

     5. Stop the trial when the discovered topology information matches
        the deployed network topology or when the discovered topology
        information returns the same details for three consecutive
        queries.

     6. Record the time for the last discovery message (Tmn) sent to
        the controller from the forwarding-plane test emulator
        interface (I1) when the trial completes successfully (e.g.,
        when the topology matches).

  Measurements:

     Topology Discovery Time (DT1) = Tmn - Tm1

                                             DT1 + DT2 + DT3 .. DTn
     Average Topology Discovery Time (TDm) = -----------------------
                                                  Total Trials

                                              SUM[SQUAREOF(DTi - TDm)]
     Topology Discovery Time Variance (TDv) = ------------------------
                                                  Total Trials - 1

  Reporting Format:

     The Topology Discovery Time results MUST be reported in tabular
     format, with a row for each successful iteration.  The last row of
     the table indicates the Topology Discovery Time variance, and the
     previous row indicates the Average Topology Discovery Time.

     If this test is repeated with a varying number of nodes over the
     same topology, the results SHOULD be reported in the form of a
     graph.  The X coordinate SHOULD be the number of nodes (N), and
     the Y coordinate SHOULD be the Average Topology Discovery Time.













Bhuvaneswaran, et al.         Informational                    [Page 12]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.1.2.  Asynchronous Message Processing Time

  Objective:

     Measure the time taken by the controller(s) to process an
     asynchronous message, defined as the interval starting with an
     asynchronous message from a Network Device after the discovery of
     all the devices by the controller(s) and ending with a response
     message from the controller(s) at its southbound interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisite:

     The controller MUST have successfully completed the network
     topology discovery for the connected Network Devices.

  Procedure:

     1. Generate asynchronous messages from every connected Network
        Device to the SDN Controller, one at a time in series from the
        forwarding-plane test emulator for the Trial Duration.

     2. Record every request transmit time (T1) and the corresponding
        response received time (R1) at the forwarding-plane test
        emulator interface (I1) for every successful message exchange.

  Measurements:

    Asynchronous Message Processing Time (APT1) =
                                                  SUM{Ri} - SUM{Ti}
                                                -----------------------
                                                           Nrx

       Where Nrx is the total number of successful messages exchanged.

    Average Asynchronous Message Processing Time =
                                             APT1 + APT2 + APT3 .. APTn
                                             --------------------------
                                                    Total Trials








Bhuvaneswaran, et al.         Informational                    [Page 13]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


    Asynchronous Message Processing Time Variance (TAMv) =
                                             SUM[SQUAREOF(APTi - TAMm)]
                                             --------------------------
                                                   Total Trials - 1

       Where TAMm is the Average Asynchronous Message Processing Time.

  Reporting Format:

     The Asynchronous Message Processing Time results MUST be reported
     in tabular format, with a row for each iteration.  The last row of
     the table indicates the Asynchronous Message Processing Time
     variance, and the previous row indicates the Average Asynchronous
     Message Processing Time.

     The report SHOULD capture the following information, in addition
     to the configuration parameters captured per Section 4.8:

        -  Successful messages exchanged (Nrx)

        -  Percentage of unsuccessful messages exchanged, computed
           using the formula ((1 - Nrx/Ntx) * 100), where Ntx is the
           total number of messages transmitted to the controller

     If this test is repeated with a varying number of nodes with the
     same topology, the results SHOULD be reported in the form of a
     graph.  The X coordinate SHOULD be the number of nodes (N), and
     the Y coordinate SHOULD be the Average Asynchronous Message
     Processing Time.

5.1.3.  Asynchronous Message Processing Rate

  Objective:

     Measure the number of responses to asynchronous messages (a new
     flow arrival notification message, link down, etc.) for which the
     controller(s) performed processing and replied with a valid and
     productive (non-trivial) response message.

     Using a single procedure, this test will measure the following two
     benchmarks on the Asynchronous Message Processing Rate (see
     Section 2.3.1.3 of [RFC8455]):

        1. Maximum Asynchronous Message Processing Rate

        2. Loss-Free Asynchronous Message Processing Rate





Bhuvaneswaran, et al.         Informational                    [Page 14]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     Here, two benchmarks are determined through a series of trials
     where the number of messages sent to the controller(s) and the
     responses received from the controller(s) are counted over the
     Trial Duration.  The message response rate and the Message Loss
     Ratio are calculated for each trial.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller(s) MUST have successfully completed the network
        topology discovery for the connected Network Devices.

     2. Choose and record the Trial Duration (Td), the sending rate
        STEP size, the tolerance on equality for two consecutive trials
        (P%), and the maximum possible message-sending rate (Ntx1/Td).

  Procedure:

     1. Generate asynchronous messages continuously at the maximum
        possible rate on the established connections from all the
        emulated/simulated Network Devices for the given Trial
        Duration (Td).

     2. Record the total number of responses received (Nrx1) from the
        controller as well as the number of messages sent (Ntx1) to the
        controller within the Trial Duration (Td).

     3. Calculate the Asynchronous Message Processing Rate (APR1) and
        the Message Loss Ratio (Lr1).  Ensure that the controller(s)
        has returned to normal operation.

     4. Repeat the trial by reducing the asynchronous message-sending
        rate used in the last trial by the STEP size.

     5. Continue repeating the trials and reducing the sending rate
        until both the maximum value of Nrxn (number of responses
        received from the controller) and the Nrxn corresponding to a
        Loss Ratio of zero have been found.









Bhuvaneswaran, et al.         Informational                    [Page 15]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     6. The trials corresponding to the benchmark levels MUST be
        repeated using the same asynchronous message rates until the
        responses received from the controller are equal (+/-P%) for
        two consecutive trials.

     7. Record the number of responses received (Nrxn) from the
        controller as well as the number of messages sent (Ntxn) to the
        controller in the last trial.

  Measurements:

                                                   Nrxn
     Asynchronous Message Processing Rate (APRn) = -----
                                                    Td

     Maximum Asynchronous Message Processing Rate = MAX(APRn) for all n

                                                 Nrxn
     Asynchronous Message Loss Ratio (Lrn) = 1 - -----
                                                 Ntxn

     Loss-Free Asynchronous Message Processing Rate = MAX(APRn)
        given Lrn = 0

  Reporting Format:

     The Asynchronous Message Processing Rate results MUST be reported
     in tabular format, with a row for each trial.

     The table should report the following information, in addition to
     the configuration parameters captured per Section 4.8, with
     columns:

        -  Offered rate (Ntxn/Td)

        -  Asynchronous Message Processing Rate (APRn)

        -  Loss Ratio (Lr)

        -  Benchmark at this iteration (blank for none, Maximum
           Asynchronous Message Processing Rate, Loss-Free Asynchronous
           Message Processing Rate)

     The results MAY be presented in the form of a graph.  The X axis
     SHOULD be the offered rate, and dual Y axes would represent the
     Asynchronous Message Processing Rate and the Loss Ratio,
     respectively.




Bhuvaneswaran, et al.         Informational                    [Page 16]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     If this test is repeated with a varying number of nodes over the
     same topology, the results SHOULD be reported in the form of a
     graph.  The X axis SHOULD be the number of nodes (N), and the
     Y axis SHOULD be the Asynchronous Message Processing Rate.  Both
     the Maximum Asynchronous Message Processing Rate and the Loss-Free
     Asynchronous Message Processing Rate should be plotted for each N.

5.1.4.  Reactive Path Provisioning Time

  Objective:

     Measure the time taken by the controller to set up a path
     reactively between source and destination nodes, defined as the
     interval starting with the first flow provisioning request message
     received by the controller(s) at its southbound interface and
     ending with the last flow provisioning response message sent from
     the controller(s) at its southbound interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.  The number of
     Network Devices in the path is a parameter of the test that may be
     varied from two to the maximum discovery size in repetitions of
     this test.

  Prerequisites:

     1. The controller MUST contain the network topology information
        for the deployed network topology.

     2. The controller should know the location of the destination
        endpoint for which the path has to be provisioned.  This can be
        achieved through dynamic learning or static provisioning.

     3. Ensure that the default action for "flow miss" in the Network
        Device is configured to "send to controller".

     4. Ensure that each Network Device in a path requires the
        controller to make the forwarding decision while paving the
        entire path.










Bhuvaneswaran, et al.         Informational                    [Page 17]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Procedure:

     1. Send a single traffic stream from test traffic generator TP1 to
        test traffic generator TP2.

     2. Record the time of the first flow provisioning request message
        sent to the controller (Tsf1) from the Network Device at the
        forwarding-plane test emulator interface (I1).

     3. Wait for the arrival of the first traffic frame at the endpoint
        (i.e., test traffic generator TP2) or the expiry of the Trial
        Duration (Td).

     4. Record the time of the last flow provisioning response message
        received from the controller (Tdf1) to the Network Device at
        the forwarding-plane test emulator interface (I1).

  Measurements:

     Reactive Path Provisioning Time (RPT1) = Tdf1 - Tsf1

     Average Reactive Path Provisioning Time =
                                             RPT1 + RPT2 + RPT3 .. RPTn
                                             --------------------------
                                                     Total Trials

     Reactive Path Provisioning Time Variance (TRPv) =
                                             SUM[SQUAREOF(RPTi - TRPm)]
                                             --------------------------
                                                    Total Trials - 1

        Where TRPm is the Average Reactive Path Provisioning Time.

  Reporting Format:

     The Reactive Path Provisioning Time results MUST be reported in
     tabular format, with a row for each iteration.  The last row of
     the table indicates the Reactive Path Provisioning Time variance,
     and the previous row indicates the Average Reactive Path
     Provisioning Time.

     The report should capture the following information, in addition
     to the configuration parameters captured per Section 4.8:

        -  Number of Network Devices in the path






Bhuvaneswaran, et al.         Informational                    [Page 18]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.1.5.  Proactive Path Provisioning Time

  Objective:

     Measure the time taken by the controller to set up a path
     proactively between source and destination nodes, defined as the
     interval starting with the first proactive flow provisioned in the
     controller(s) at its northbound interface and ending with the last
     flow provisioning response message sent from the controller(s) at
     its southbound interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST contain the network topology information
        for the deployed network topology.

     2. The controller should know the location of the destination
        endpoint for which the path has to be provisioned.  This can be
        achieved through dynamic learning or static provisioning.

     3. Ensure that the default action for "flow miss" in the Network
        Device is "drop".

  Procedure:

     1. Send a single traffic stream from test traffic generator TP1 to
        test traffic generator TP2.

     2. Install the flow entries so that the traffic travels from test
        traffic generator TP1 until it reaches test traffic
        generator TP2 through the controller's northbound interface or
        management interface.

     3. Wait for the arrival of the first traffic frame at test traffic
        generator TP2 or the expiry of the Trial Duration (Td).

     4. Record the time when the proactive flow is provisioned in the
        controller (Tsf1) at the management-plane test emulator
        interface (I2).

     5. Record the time of the last flow provisioning message received
        from the controller (Tdf1) at the forwarding-plane test
        emulator interface (I1).



Bhuvaneswaran, et al.         Informational                    [Page 19]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

     Proactive Flow Provisioning Time (PPT1) = Tdf1 - Tsf1

     Average Proactive Path Provisioning Time =
                                             PPT1 + PPT2 + PPT3 .. PPTn
                                             --------------------------
                                                     Total Trials

     Proactive Path Provisioning Time Variance (TPPv) =
                                             SUM[SQUAREOF(PPTi - TPPm)]
                                             --------------------------
                                                  Total Trials - 1

        Where TPPm is the Average Proactive Path Provisioning Time.

  Reporting Format:

     The Proactive Path Provisioning Time results MUST be reported in
     tabular format, with a row for each iteration.  The last row of
     the table indicates the Proactive Path Provisioning Time variance,
     and the previous row indicates the Average Proactive Path
     Provisioning Time.

     The report should capture the following information, in addition
     to the configuration parameters captured per Section 4.8:

        -  Number of Network Devices in the path























Bhuvaneswaran, et al.         Informational                    [Page 20]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.1.6.  Reactive Path Provisioning Rate

  Objective:

     Measure the maximum number of independent paths a controller can
     concurrently establish per second between source and destination
     nodes reactively, defined as the number of paths provisioned per
     second by the controller(s) at its southbound interface for the
     flow provisioning requests received for path provisioning at its
     southbound interface between the start of the test and the expiry
     of the given Trial Duration.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST contain the network topology information
        for the deployed network topology.

     2. The controller should know the location of destination
        addresses for which the paths have to be provisioned.  This can
        be achieved through dynamic learning or static provisioning.

     3. Ensure that the default action for "flow miss" in the Network
        Device is configured to "send to controller".

     4. Ensure that each Network Device in a path requires the
        controller to make the forwarding decision while provisioning
        the entire path.

  Procedure:

     1. Send traffic with unique source and destination addresses from
        test traffic generator TP1.

     2. Record the total number of unique traffic frames (Ndf) received
        at test traffic generator TP2 within the Trial Duration (Td).











Bhuvaneswaran, et al.         Informational                    [Page 21]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

                                               Ndf
     Reactive Path Provisioning Rate (RPR1) = ------
                                               Td

     Average Reactive Path Provisioning Rate =
                                             RPR1 + RPR2 + RPR3 .. RPRn
                                             --------------------------
                                                    Total Trials

     Reactive Path Provisioning Rate Variance (RPPv) =
                                             SUM[SQUAREOF(RPRi - RPPm)]
                                             --------------------------
                                                   Total Trials - 1

        Where RPPm is the Average Reactive Path Provisioning Rate.

  Reporting Format:

     The Reactive Path Provisioning Rate results MUST be reported in
     tabular format, with a row for each iteration.  The last row of
     the table indicates the Reactive Path Provisioning Rate variance,
     and the previous row indicates the Average Reactive Path
     Provisioning Rate.

     The report should capture the following information, in addition
     to the configuration parameters captured per Section 4.8:

        -  Number of Network Devices in the path

        -  Offered rate



















Bhuvaneswaran, et al.         Informational                    [Page 22]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.1.7.  Proactive Path Provisioning Rate

  Objective:

     Measure the maximum number of independent paths a controller can
     concurrently establish per second between source and destination
     nodes proactively, defined as the number of paths provisioned per
     second by the controller(s) at its southbound interface for the
     paths requested in its northbound interface between the start of
     the test and the expiry of the given Trial Duration.  The
     measurement is based on data-plane observations of successful path
     activation.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST contain the network topology information
        for the deployed network topology.

     2. The controller should know the location of destination
        addresses for which the paths have to be provisioned.  This can
        be achieved through dynamic learning or static provisioning.

     3. Ensure that the default action for "flow miss" in the Network
        Device is "drop".

  Procedure:

     1. Send traffic continuously with unique source and destination
        addresses from test traffic generator TP1.

     2. Install corresponding flow entries so that the traffic travels
        from simulated sources at test traffic generator TP1 until it
        reaches the simulated destinations at test traffic
        generator TP2 through the controller's northbound interface or
        management interface.

     3. Record the total number of unique traffic frames (Ndf) received
        at test traffic generator TP2 within the Trial Duration (Td).








Bhuvaneswaran, et al.         Informational                    [Page 23]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

                                                Ndf
     Proactive Path Provisioning Rate (PPR1) = ------
                                                Td

     Average Proactive Path Provisioning Rate =
                                             PPR1 + PPR2 + PPR3 .. PPRn
                                             --------------------------
                                                     Total Trials

     Proactive Path Provisioning Rate Variance (PPPv) =
                                             SUM[SQUAREOF(PPRi - PPPm)]
                                             -------------------------
                                                  Total Trials - 1

        Where PPPm is the Average Proactive Path Provisioning Rate.

  Reporting Format:

     The Proactive Path Provisioning Rate results MUST be reported in
     tabular format, with a row for each iteration.  The last row of
     the table indicates the Proactive Path Provisioning Rate variance,
     and the previous row indicates the Average Proactive Path
     Provisioning Rate.

     The report should capture the following information, in addition
     to the configuration parameters captured per Section 4.8:

        -  Number of Network Devices in the path

        -  Offered rate



















Bhuvaneswaran, et al.         Informational                    [Page 24]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.1.8.  Network Topology Change Detection Time

  Objective:

     Measure the amount of time taken by the controller to detect any
     changes in the network topology, defined as the interval starting
     with the notification message received by the controller(s) at its
     southbound interface and ending with the first topology
     rediscovery message sent from the controller(s) at its southbound
     interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST have successfully discovered the network
        topology information for the deployed network topology.

     2. The periodic network discovery operation should be configured
        to twice the Trial Duration (Td) value.

  Procedure:

     1. Trigger a topology change event by bringing down an active
        Network Device in the topology.

     2. Record the time when the first topology change notification is
        sent to the controller (Tcn) at the forwarding-plane test
        emulator interface (I1).

     3. Stop the trial when the controller sends the first topology
        rediscovery message to the Network Device or the expiry of the
        Trial Duration (Td).

     4. Record the time when the first topology rediscovery message is
        received from the controller (Tcd) at the forwarding-plane test
        emulator interface (I1).











Bhuvaneswaran, et al.         Informational                    [Page 25]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

     Network Topology Change Detection Time (TDT1) = Tcd - Tcn

     Average Network Topology Change Detection Time =
                                             TDT1 + TDT2 + TDT3 .. TDTn
                                             --------------------------
                                                     Total Trials

     Network Topology Change Detection Time Variance (NTDv) =
                                             SUM[SQUAREOF(TDTi - NTDm)]
                                             --------------------------
                                                   Total Trials - 1

        Where NTDm is the Average Network Topology Change
           Detection Time.

  Reporting Format:

     The Network Topology Change Detection Time results MUST be
     reported in tabular format, with a row for each iteration.  The
     last row of the table indicates the Network Topology Change
     Detection Time variance, and the previous row indicates the
     Average Network Topology Change Detection Time.

5.2.  Scalability

5.2.1.  Control Sessions Capacity

  Objective:

     Measure the maximum number of control sessions the controller can
     maintain, defined as the number of sessions that the controller
     can accept from Network Devices, starting with the first control
     session and ending with the last control session that the
     controller(s) accepts at its southbound interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     None






Bhuvaneswaran, et al.         Informational                    [Page 26]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Procedure:

     1. Establish control connections with the controller from every
        Network Device emulated in the forwarding-plane test emulator.

     2. Stop the trial when the controller starts dropping the control
        connections.

     3. Record the number of successful connections established (CCn)
        with the controller at the forwarding-plane test emulator.

  Measurement:

     Control Sessions Capacity = CCn

  Reporting Format:

     The Control Sessions Capacity results MUST be reported in addition
     to the configuration parameters captured per Section 4.8.

5.2.2.  Network Discovery Size

  Objective:

     Measure the network size (number of nodes, links, and hosts) that
     a controller can discover, defined as the size of a network that
     the controller(s) can discover, starting with a network topology
     provided by the user for discovery and ending with the number of
     nodes, links, and hosts that the controller(s) were able to
     successfully discover.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller MUST support automatic network discovery.

     2. The tester should be able to retrieve the discovered topology
        information through either the controller's management
        interface or northbound interface.








Bhuvaneswaran, et al.         Informational                    [Page 27]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Procedure:

     1. Establish the network connections between the controller and
        the network nodes.

     2. Query the controller every t seconds (the RECOMMENDED value for
        t is 30) to obtain the discovered network topology information
        through the northbound interface or the management interface.

     3. Stop the trial when the discovered network topology information
        remains the same as that of the last two query responses.

     4. Compare the obtained network topology information with the
        deployed network topology information.

     5. If the comparison is successful, increase the number of nodes
        by 1 and repeat the trial.
        If the comparison is unsuccessful, decrease the number of nodes
        by 1 and repeat the trial.

     6. Continue the trial until the comparison (step 5) is successful.

     7. Record the number of nodes for the last trial run (Ns) where
        the topology comparison was successful.

  Measurement:

      Network Discovery Size = Ns

  Reporting Format:

     The Network Discovery Size results MUST be reported in addition to
     the configuration parameters captured per Section 4.8.


















Bhuvaneswaran, et al.         Informational                    [Page 28]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.2.3.  Forwarding Table Capacity

  Objective:

     Measure the maximum number of flow entries a controller can manage
     in its Forwarding Table.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. The controller's Forwarding Table should be empty.

     2. "Flow idle time" MUST be set to a higher or infinite value.

     3. The controller MUST have successfully completed network
        topology discovery.

     4. The tester should be able to retrieve the Forwarding Table
        information through either the controller's management
        interface or northbound interface.

  Procedures:

     o  Reactive Flow Provisioning Mode:

        1. Send bidirectional traffic continuously with unique source
           and destination addresses from test traffic generators TP1
           and TP2 at the Asynchronous Message Processing Rate of the
           controller.

        2. Query the controller at a regular interval (e.g., every
           5 seconds) for the number of learned flow entries from its
           northbound interface.

        3. Stop the trial when the retrieved value is constant for
           three consecutive iterations, and record the value received
           from the last query (Nrp).










Bhuvaneswaran, et al.         Informational                    [Page 29]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


     o  Proactive Flow Provisioning Mode:

        1. Install unique flows continuously through the controller's
           northbound interface or management interface until a failure
           response is received from the controller.

        2. Record the total number of successful responses (Nrp).

        Note:

        Some controller designs for Proactive Flow Provisioning mode
        may require the switch to send flow setup requests in order to
        generate flow setup responses.  In such cases, it is
        recommended to generate bidirectional traffic for the
        provisioned flows.

  Measurements:

     Proactive Flow Provisioning Mode:

        Max Flow Entries = Total number of flows provisioned (Nrp)

     Reactive Flow Provisioning Mode:

        Max Flow Entries = Total number of learned flow entries (Nrp)

     Forwarding Table Capacity = Max Flow Entries

  Reporting Format:

     The Forwarding Table Capacity results MUST be tabulated with the
     following information, in addition to the configuration parameters
     captured per Section 4.8:

        -  Provisioning Type (Proactive/Reactive)
















Bhuvaneswaran, et al.         Informational                    [Page 30]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.3.  Security

5.3.1.  Exception Handling

  Objective:

     Determine the effects of handling error packets and notifications
     on performance tests.  The impact MUST be measured for the
     following performance tests:

        1. Path Provisioning Rate

        2. Path Provisioning Time

        3. Network Topology Change Detection Time

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. This test MUST be performed after obtaining the baseline
        measurement results for the performance tests listed above.

     2. Ensure that the invalid messages are not dropped by the
        intermediate devices connecting the controller and Network
        Devices.

  Procedure:

     1. Perform the above-listed performance tests, and send 1% of the
        messages from the Asynchronous Message Processing Rate test
        (Section 5.1.3) as invalid messages from the connected Network
        Devices emulated at the forwarding-plane test emulator.

     2. Perform the above-listed performance tests, and send 2% of the
        messages from the Asynchronous Message Processing Rate test
        (Section 5.1.3) as invalid messages from the connected Network
        Devices emulated at the forwarding-plane test emulator.

     Note:

     Invalid messages can be frames with incorrect protocol fields or
     any form of failure notifications sent towards the controller.





Bhuvaneswaran, et al.         Informational                    [Page 31]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

     Measurements MUST be done as per the equation defined in the
     "Measurements" section of the corresponding test listed under
     "Objective".

  Reporting Format:

     The Exception Handling results MUST be reported in tabular format,
     with a column for each of the below parameters and row for each of
     the above-listed performance tests:

        -  Without Exceptions

        -  With 1% Exceptions

        -  With 2% Exceptions

5.3.2.  Handling Denial-of-Service Attacks

  Objective:

     Determine the effects of handling DoS attacks on performance and
     scalability tests.  The impact MUST be measured for the following
     tests:

        1. Path Provisioning Rate

        2. Path Provisioning Time

        3. Network Topology Change Detection Time

        4. Network Discovery Size

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisite:

     This test MUST be performed after obtaining the baseline
     measurement results for the performance tests listed above.








Bhuvaneswaran, et al.         Informational                    [Page 32]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Procedure:

     Perform the above-listed tests, and launch a DoS attack towards
     the controller while the trial is running.

     Note: DoS attacks can be launched on one of the following
     interfaces:

        1. Northbound (e.g., query for flow entries continuously on the
           northbound interface)

        2. Management (e.g., Ping requests to the controller's
           management interface)

        3. Southbound (e.g., TCP SYN messages on the southbound
           interface)

  Measurements:

     Measurements MUST be done as per the equation defined in the
     "Measurements" section of the corresponding test listed under
     "Objective".

  Reporting Format:

     The results regarding the handling of DoS attacks MUST be reported
     in tabular format, with a column for each of the below parameters
     and a row for each of the above-listed tests.

        -  Without any attacks

        -  With attacks

     The report should also specify the nature of the attack and the
     interface in question.
















Bhuvaneswaran, et al.         Informational                    [Page 33]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.4.  Reliability

5.4.1.  Controller Failover Time

  Objective:

     Measure the time taken to switch from an active controller to the
     backup controller when the controllers work in redundancy mode and
     the active controller fails, defined as the interval starting when
     the active controller is brought down and ending with the first
     rediscovery message received from the new controller at its
     southbound interface.

  Reference Test Setup:

     This test SHOULD use the test setup illustrated in Section 3.2 of
     this document.

  Prerequisites:

     1. Master controller election MUST be completed.

     2. Nodes are connected to the controller cluster per the
        implemented redundancy mode (e.g., active-standby).

     3. The controller cluster should have successfully completed the
        network topology discovery.

     4. The Network Device MUST send all new flows to the controller
        when it receives them from the test traffic generator.

     5. The controller should have learned the location of the
        destination (D1) at test traffic generator TP2.


















Bhuvaneswaran, et al.         Informational                    [Page 34]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Procedure:

     1. Send unidirectional traffic continuously with incremental
        sequence numbers and source addresses from test traffic
        generator TP1 at the rate at which the controller can process
        the traffic without any drops.

     2. Ensure that there are no packet drops observed at test traffic
        generator TP2.

     3. Bring down the active controller.

     4. Stop the trial when the first frame after the failover
        operation is received on test traffic generator TP2.

     5. Record the time at which the last valid frame was received (T1)
        at test traffic generator TP2 before the sequence error and the
        time at which the first valid frame was received (T2) after the
        sequence error at test traffic generator TP2.

  Measurements:

     Controller Failover Time = (T2 - T1)

     Packet Loss = Number of missing packet sequences

  Reporting Format:

     The Controller Failover Time results MUST be tabulated with the
     following information:

        -  Number of cluster nodes

        -  Redundancy mode

        -  Controller Failover Time

        -  Packet Loss

        -  Cluster keep-alive interval











Bhuvaneswaran, et al.         Informational                    [Page 35]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


5.4.2.  Network Re-provisioning Time

  Objective:

     Measure the time taken by the controller to reroute traffic when
     there is a failure in existing traffic paths, defined as the
     interval starting with the first failure notification message
     received by the controller and ending with the last flow
     re-provisioning message sent by the controller at its southbound
     interface.

  Reference Test Setup:

     This test SHOULD use one of the test setups illustrated in
     Section 3.1 or Section 3.2 of this document.

  Prerequisites:

     1. A network with a specified number of nodes and redundant paths
        MUST be deployed.

     2. The controller MUST know the location of test traffic
        generators TP1 and TP2.

     3. Ensure that the controller does not pre-provision the alternate
        path in the emulated Network Devices at the forwarding-plane
        test emulator.

  Procedure:

     1. Send bidirectional traffic continuously with a unique sequence
        number from test traffic generators TP1 and TP2.

     2. Bring down a link or switch in the traffic path.

     3. Stop the trial after receiving the first frame after network
        reconvergence.

     4. Record the time of the last received frame prior to the frame
        loss at test traffic generator TP2 (TP2-Tlfr) and the time of
        the first frame received after the frame loss at test traffic
        generator TP2 (TP2-Tffr).  There must be a gap in sequence
        numbers of these frames.

     5. Record the time of the last received frame prior to the frame
        loss at test traffic generator TP1 (TP1-Tlfr) and the time of
        the first frame received after the frame loss at test traffic
        generator TP1 (TP1-Tffr).



Bhuvaneswaran, et al.         Informational                    [Page 36]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Measurements:

     Forward Direction Path Re-provisioning Time (FDRT)
                                                = (TP2-Tffr - TP2-Tlfr)

     Reverse Direction Path Re-provisioning Time (RDRT)
                                                = (TP1-Tffr - TP1-Tlfr)

     Network Re-provisioning Time = (FDRT + RDRT)/2

     Forward Direction Packet Loss = Number of missing sequence frames
        at test traffic generator TP1

     Reverse Direction Packet Loss = Number of missing sequence frames
        at test traffic generator TP2

  Reporting Format:

     The Network Re-provisioning Time results MUST be tabulated with
     the following information:

        -  Number of nodes in the primary path

        -  Number of nodes in the alternate path

        -  Network Re-provisioning Time

        -  Forward Direction Packet Loss

        -  Reverse Direction Packet Loss

6.  IANA Considerations

  This document has no IANA actions.

















Bhuvaneswaran, et al.         Informational                    [Page 37]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


7.  Security Considerations

  The benchmarking tests described in this document are limited to the
  performance characterization of controllers in a lab environment with
  isolated networks.

  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 controller.

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

8.  References

8.1.  Normative References

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

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

  [RFC8455]  Bhuvaneswaran, V., Basil, A., Tassinari, M., Manral, V.,
             and S. Banks, "Terminology for Benchmarking
             Software-Defined Networking (SDN) Controller Performance",
             RFC 8455, DOI 10.17487/RFC8455, October 2018,
             <https://www.rfc-editor.org/info/rfc8455>.

8.2.  Informative References

  [OpenFlow-Spec]
             ONF, "OpenFlow Switch Specification" Version 1.4.0 (Wire
             Protocol 0x05), October 2013,
             <https://www.opennetworking.org/wp-content/
             uploads/2014/10/openflow-spec-v1.4.0.pdf>.





Bhuvaneswaran, et al.         Informational                    [Page 38]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


Appendix A.  Benchmarking Methodology Using OpenFlow Controllers

  This section gives an overview of the OpenFlow protocol
  [OpenFlow-Spec] and provides a test methodology for benchmarking SDN
  Controllers supporting the OpenFlow southbound protocol.  The
  OpenFlow protocol is used as an example to illustrate the
  methodologies defined in this document.

A.1.  Protocol Overview

  OpenFlow [OpenFlow-Spec] is an open standard protocol defined by the
  Open Networking Foundation (ONF) and used for programming the
  forwarding plane of network switches or routers via a centralized
  controller.

A.2.  Messages Overview

  The OpenFlow protocol supports three message types -- namely,
  controller-to-switch, asynchronous, and symmetric.

  Controller-to-switch messages are initiated by the controller and
  used to directly manage or inspect the state of the switch.  These
  messages allow controllers to query/configure the switch ("features"
  messages, configuration messages), collect information from a switch
  (Read-State messages), send packets on a specified port of a switch
  (OFPT_PACKET_OUT messages), and modify the switch forwarding plane
  and state (Modify-State messages, Role-Request messages, etc.).

  Asynchronous messages are generated by the switch without a
  controller soliciting them.  These messages allow switches to update
  controllers to denote an arrival of a new flow (OFPT_PACKET_IN
  messages), switch state changes ("flow-removed" messages, port-status
  messages), and errors (Error messages).

  Symmetric messages are generated in either direction without
  solicitation.  These messages allow switches and controllers to set
  up a connection (Hello messages), verify liveness (Echo messages),
  and offer additional functionalities (Experimenter messages).

A.3.  Connection Overview

  The OpenFlow channel is used to exchange OpenFlow messages between an
  OpenFlow switch and an OpenFlow controller.  The OpenFlow channel
  connection can be set up using plain TCP or TLS.  By default, a
  switch establishes a single connection with the SDN Controller.  A
  switch may establish multiple parallel connections to a single
  controller (auxiliary connection) or multiple controllers to handle
  controller failures and load balancing.



Bhuvaneswaran, et al.         Informational                    [Page 39]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.  Performance Benchmarking Tests

A.4.1.  Network Topology Discovery Time

  Procedure:

     Network Devices               OpenFlow                    SDN
                                  Controller               Application
           |                            |                           |
           |                            |<Initialize controller     |
           |                            |app., NB and SB interfaces>|
           |                            |                           |
           |<Deploy network with        |                           |
           | given no. of OF switches>  |                           |
           |                            |                           |
           |    OFPT_HELLO Exchange     |                           |
           |<-------------------------->|                           |
           |                            |                           |
           |   OFPT_PACKET_OUT with LLDP|                           |
           |             to all switches|                           |
      (Tm1)|<---------------------------|                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch 1|                           |
           |--------------------------->|                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch 2|                           |
           |--------------------------->|                           |
           |            .               |                           |
           |            .               |                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch n|                           |
      (Tmn)|--------------------------->|                           |
           |                            |                           |
           |                            |    <Wait for the expiry of|
           |                            |   the Trial Duration (Td)>|
           |                            |                           |
           |                            |   Query the controller for|
           |                            |  discovered n/w topo. (Di)|
           |                            |<--------------------------|
           |                            |                           |
           |                            |    <Compare the discovered|
           |                            |       n/w topology and the|
           |                            |      offered n/w topology>|
           |                            |                           |




Bhuvaneswaran, et al.         Informational                    [Page 40]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     NB: Northbound
     SB: Southbound
     OF: OpenFlow
     OFP: OpenFlow Protocol
     LLDP: Link-Layer Discovery Protocol
     Tm1: Time of reception of first LLDP message from controller
     Tmn: Time of last LLDP message sent to controller

  Discussion:

     The Network Topology Discovery Time can be obtained by calculating
     the time difference between the first OFPT_PACKET_OUT with an LLDP
     message received from the controller (Tm1) and the last
     OFPT_PACKET_IN with an LLDP message sent to the controller (Tmn)
     when the comparison is successful.


































Bhuvaneswaran, et al.         Informational                    [Page 41]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.2.  Asynchronous Message Processing Time

  Procedure:

        Network Devices            OpenFlow                    SDN
                                  Controller               Application
           |                            |                           |
           |OFPT_PACKET_IN with single  |                           |
           |OFP match header            |                           |
       (T0)|--------------------------->|                           |
           |                            |                           |
           |OFPT_PACKET_OUT with single |                           |
           |          OFP action header |                           |
       (R0)|<---------------------------|                           |
           |          .                 |                           |
           |          .                 |                           |
           |          .                 |                           |
           |                            |                           |
           |OFPT_PACKET_IN with single  |                           |
           |OFP match header            |                           |
       (Tn)|--------------------------->|                           |
           |                            |                           |
           |OFPT_PACKET_OUT with single |                           |
           |          OFP action header |                           |
       (Rn)|<---------------------------|                           |
           |                            |                           |
           |<Wait for the expiry of the |                           |
           |Trial Duration>             |                           |
           |                            |                           |
           |<Record the number of       |                           |
           |OFPT_PACKET_INs/            |                           |
           |OFPT_PACKET_OUTs            |                           |
           |exchanged (Nrx)>            |                           |
           |                            |                           |

  Legend:

     T0,T1, ..Tn: transmit timestamps of OFPT_PACKET_IN messages
     R0,R1, ..Rn: receive timestamps of OFPT_PACKET_OUT messages
     Nrx: Number of successful OFPT_PACKET_IN/OFPT_PACKET_OUT
          message exchanges

  Discussion:

     The Asynchronous Message Processing Time will be obtained by
     calculating the sum of ((R0 - T0),(R1 - T1)..(Rn - Tn))/Nrx.





Bhuvaneswaran, et al.         Informational                    [Page 42]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.3.  Asynchronous Message Processing Rate

  Procedure:

        Network Devices           OpenFlow                    SDN
                                 Controller               Application
           |                            |                          |
           |OFPT_PACKET_IN with single  |                          |
           |OFP match header            |                          |
           |--------------------------->|                          |
           |                            |                          |
           |OFPT_PACKET_OUT with single |                          |
           |          OFP action header |                          |
           |<---------------------------|                          |
           |                            |                          |
           |            .               |                          |
           |            .               |                          |
           |            .               |                          |
           |                            |                          |
           |OFPT_PACKET_IN with single  |                          |
           |OFP match header            |                          |
           |--------------------------->|                          |
           |                            |                          |
           |OFPT_PACKET_OUT with single |                          |
           |          OFP action header |                          |
           |<---------------------------|                          |
           |                            |                          |
           |<Repeat the steps until     |                          |
           |the expiry of the           |                          |
           |Trial Duration>             |                          |
           |                            |                          |
           |<Record the number of OFP   |                          |
     (Ntx1)|match headers sent>         |                          |
           |                            |                          |
           |<Record the number of OFP   |                          |
     (Nrx1)|action headers rcvd>        |                          |
           |                            |                          |

     Note: The Ntx1 on initial trials should be greater than Nrx1.
     Repeat the trials until the Nrxn for two consecutive trials equals
     (+/-P%).










Bhuvaneswaran, et al.         Informational                    [Page 43]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Discussion:

     Using a single procedure, this test will measure two benchmarks:

        1. The Maximum Asynchronous Message Processing Rate will be
           obtained by calculating the maximum OFPT_PACKET_OUTs (Nrxn)
           received from the controller(s) across n trials.

        2. The Loss-Free Asynchronous Message Processing Rate will be
           obtained by calculating the maximum OFPT_PACKET_OUTs
           received from the controller(s) when the Loss Ratio equals
           zero.  The Loss Ratio is obtained by calculating
           1 - Nrxn/Ntxn.

A.4.4.  Reactive Path Provisioning Time

  Procedure:

      Test Traffic     Test Traffic      Network Devices      OpenFlow
     Generator TP1    Generator TP2                          Controller
           |             |                      |                     |
           |             |G-ARP (D1)            |                     |
           |             |--------------------->|                     |
           |             |                      |                     |
           |             |                      |OFPT_PACKET_IN(D1)   |
           |             |                      |-------------------->|
           |             |                      |                     |
           |Traffic (S1,D1)                     |                     |
     (Tsf1)|----------------------------------->|                     |
           |             |                      |                     |
           |             |                      |                     |
           |             |                      |                     |
           |             |                      |OFPT_PACKET_IN(S1,D1)|
           |             |                      |-------------------->|
           |             |                      |                     |
           |             |                      |  FLOW_MOD(D1)       |
           |             |                      |<--------------------|
           |             |                      |                     |
           |             |Traffic (S1,D1)       |                     |
           |       (Tdf1)|<---------------------|                     |
           |             |                      |                     |










Bhuvaneswaran, et al.         Informational                    [Page 44]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     G-ARP: Gratuitous ARP message
     Tsf1: Time of first frame sent from TP1
     Tdf1: Time of first frame received from TP2

  Discussion:

     The Reactive Path Provisioning Time can be obtained by finding the
     time difference between the transmit and receive times of the
     traffic (Tsf1 - Tdf1).








































Bhuvaneswaran, et al.         Informational                    [Page 45]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.5.  Proactive Path Provisioning Time

  Procedure:

  Test Traffic  Test Traffic    Network Devices OpenFlow       SDN
  Generator TP1 Generator TP2                  Controller   Application
        |            |               |                  |             |
        |            |               |                  |             |
        |            |               |                  |<Install flow|
        |            |               |                  |  for S1,D1> |
        |            |G-ARP (D1)     |                  |             |
        |            |-------------->|                  |             |
        |            |               |                  |             |
        |            |               |OFPT_PACKET_IN(D1)|             |
        |            |               |----------------->|             |
        |            |               |                  |             |
        |Traffic (S1,D1)             |                  |             |
  (Tsf1)|--------------------------->|                  |             |
        |            |               |                  |             |
        |            |               |   FLOW_MOD(D1)   |             |
        |            |               |<-----------------|             |
        |            |               |                  |             |
        |            |Traffic (S1,D1)|                  |             |
        |      (Tdf1)|<--------------|                  |             |
        |            |               |                  |             |

  Legend:

     G-ARP: Gratuitous ARP message
     Tsf1: Time of first frame sent from TP1
     Tdf1: Time of first frame received from TP2

  Discussion:

     The Proactive Path Provisioning Time can be obtained by finding
     the time difference between the transmit and receive times of the
     traffic (Tsf1 - Tdf1).














Bhuvaneswaran, et al.         Informational                    [Page 46]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.6.  Reactive Path Provisioning Rate

  Procedure:

      Test Traffic     Test Traffic   Network Devices         OpenFlow
     Generator TP1    Generator TP2                         Controller
           |             |                    |                      |
           |             |                    |                      |
           |             |                    |                      |
           |             |G-ARP (D1..Dn)      |                      |
           |             |--------------------|                      |
           |             |                    |                      |
           |             |                    |OFPT_PACKET_IN(D1..Dn)|
           |             |                    |--------------------->|
           |             |                    |                      |
           |Traffic (S1..Sn,D1..Dn)           |                      |
           |--------------------------------->|                      |
           |             |                    |                      |
           |             |                    |OFPT_PACKET_IN(S1..Sn,|
           |             |                    |               D1..Dn)|
           |             |                    |--------------------->|
           |             |                    |                      |
           |             |                    |        FLOW_MOD(S1)  |
           |             |                    |<---------------------|
           |             |                    |                      |
           |             |                    |        FLOW_MOD(D1)  |
           |             |                    |<---------------------|
           |             |                    |                      |
           |             |                    |        FLOW_MOD(S2)  |
           |             |                    |<---------------------|
           |             |                    |                      |
           |             |                    |        FLOW_MOD(D2)  |
           |             |                    |<---------------------|
           |             |                    |             .        |
           |             |                    |             .        |
           |             |                    |                      |
           |             |                    |        FLOW_MOD(Sn)  |
           |             |                    |<---------------------|
           |             |                    |                      |
           |             |                    |        FLOW_MOD(Dn)  |
           |             |                    |<---------------------|
           |             |                    |                      |
           |             | Traffic (S1..Sn,   |                      |
           |             |             D1..Dn)|                      |
           |             |<-------------------|                      |
           |             |                    |                      |
           |             |                    |                      |




Bhuvaneswaran, et al.         Informational                    [Page 47]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     G-ARP: Gratuitous ARP message
     D1..Dn: Destination Endpoint 1, Destination Endpoint 2 ...,
             Destination Endpoint n
     S1..Sn: Source Endpoint 1, Source Endpoint 2 ...,
             Source Endpoint n

  Discussion:

     The Reactive Path Provisioning Rate can be obtained by finding the
     total number of frames received at test traffic generator TP2
     after the Trial Duration.






































Bhuvaneswaran, et al.         Informational                    [Page 48]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.4.7.  Proactive Path Provisioning Rate

  Procedure:

  Test Traffic  Test Traffic   Network Devices   OpenFlow        SDN
  Generator TP1 Generator TP2                   Controller  Application
        |            |                |                 |             |
        |            |G-ARP (D1..Dn)  |                 |             |
        |            |--------------->|                 |             |
        |            |                |                 |             |
        |            |                |OFPT_PACKET_IN   |             |
        |            |                |         (D1..Dn)|             |
        |            |                |---------------->|             |
        |            |                |                 |             |
        |Traffic (S1..Sn,D1..Dn)      |                 |             |
  (Tsf1)|---------------------------->|                 |             |
        |            |                |                 |             |
        |            |                |                 |<Install flow|
        |            |                |                 |  for S1,D1> |
        |            |                |                 |             |
        |            |                |                 |       .     |
        |            |                |                 |<Install flow|
        |            |                |                 |  for Sn,Dn> |
        |            |                |                 |             |
        |            |                |  FLOW_MOD(S1)   |             |
        |            |                |<----------------|             |
        |            |                |                 |             |
        |            |                |  FLOW_MOD(D1)   |             |
        |            |                |<----------------|             |
        |            |                |                 |             |
        |            |                |       .         |             |
        |            |                |  FLOW_MOD(Sn)   |             |
        |            |                |<----------------|             |
        |            |                |                 |             |
        |            |                |  FLOW_MOD(Dn)   |             |
        |            |                |<----------------|             |
        |            |                |                 |             |
        |            |Traffic (S1..Sn,|                 |             |
        |            |         D1..Dn)|                 |             |
        |      (Tdf1)|<---------------|                 |             |
        |            |                |                 |             |










Bhuvaneswaran, et al.         Informational                    [Page 49]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     G-ARP: Gratuitous ARP message
     D1..Dn: Destination Endpoint 1, Destination Endpoint 2 ...,
             Destination Endpoint n
     S1..Sn: Source Endpoint 1, Source Endpoint 2 ...,
             Source Endpoint n

  Discussion:

     The Proactive Path Provisioning Rate can be obtained by finding
     the total number of frames received at test traffic generator TP2
     after the Trial Duration.

A.4.8.  Network Topology Change Detection Time

  Procedure:

      Network Devices              OpenFlow                    SDN
                                  Controller               Application
           |                            |                           |
           |                            |     <Bring down a link in |
           |                            |                 Switch S1>|
           |                            |                           |
        T0 |PORT_STATUS with link down  |                           |
           | from S1                    |                           |
           |--------------------------->|                           |
           |                            |                           |
           |First OFPT_PACKET_OUT with  |                           |
           |LLDP to OF switch           |                           |
        T1 |<---------------------------|                           |
           |                            |                           |
           |                            |      <Record time of first|
           |                            |       OFPT_PACKET_OUT with|
           |                            |                   LLDP T1>|
           |                            |                           |

  Discussion:

     The Network Topology Change Detection Time can be obtained by
     finding the difference between the time that OpenFlow Switch S1
     sends the PORT_STATUS message (T0) and the time that the OpenFlow
     controller sends the first topology rediscovery message (T1) to
     OpenFlow switches.







Bhuvaneswaran, et al.         Informational                    [Page 50]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.5.  Scalability

A.5.1.  Control Sessions Capacity

  Procedure:

        Network Devices                        OpenFlow
                                              Controller
           |                                       |
           |    OFPT_HELLO Exchange for Switch 1   |
           |<------------------------------------->|
           |                                       |
           |    OFPT_HELLO Exchange for Switch 2   |
           |<------------------------------------->|
           |                  .                    |
           |                  .                    |
           |                  .                    |
           |    OFPT_HELLO Exchange for Switch n   |
           |X<----------------------------------->X|
           |                                       |

  Discussion:

     The value of Switch (n - 1) will provide the Control Sessions
     Capacity.


























Bhuvaneswaran, et al.         Informational                    [Page 51]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.5.2.  Network Discovery Size

  Procedure:

      Network Devices              OpenFlow                    SDN
                                  Controller               Application
           |                            |                           |
           |                            |     <Deploy network with  |
           |                            |given no. of OF switches N>|
           |                            |                           |
           |    OFPT_HELLO Exchange     |                           |
           |<-------------------------->|                           |
           |                            |                           |
           |   OFPT_PACKET_OUT with LLDP|                           |
           |      to all switches       |                           |
           |<---------------------------|                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch 1|                           |
           |--------------------------->|                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch 2|                           |
           |--------------------------->|                           |
           |            .               |                           |
           |            .               |                           |
           |                            |                           |
           |    OFPT_PACKET_IN with LLDP|                           |
           |          rcvd from Switch n|                           |
           |--------------------------->|                           |
           |                            |                           |
           |                            |    <Wait for the expiry of|
           |                            |   the Trial Duration (Td)>|
           |                            |                           |
           |                            |   Query the controller for|
           |                            |  discovered n/w topo. (N1)|
           |                            |<--------------------------|
           |                            |                           |
           |                            |   <If N1==N, repeat Step 1|
           |                            |           with N + 1 nodes|
           |                            |               until N1<N >|
           |                            |                           |
           |                            |   <If N1<N, repeat Step 1 |
           |                            | with N=N1 nodes once and  |
           |                            | exit>                     |
           |                            |                           |





Bhuvaneswaran, et al.         Informational                    [Page 52]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     n/w topo: Network topology
     OF: OpenFlow

  Discussion:

     The value of N1 provides the Network Discovery Size value.  The
     Trial Duration can be set to the stipulated time within which the
     user expects the controller to complete the discovery process.









































Bhuvaneswaran, et al.         Informational                    [Page 53]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.5.3.  Forwarding Table Capacity

  Procedure:

  Test Traffic     Network Devices        OpenFlow          SDN
  Generator TP1                           Controller     Application
       |                 |                      |                 |
       |                 |                      |                 |
       |G-ARP (H1..Hn)   |                      |                 |
       |---------------->|                      |                 |
       |                 |                      |                 |
       |                 |OFPT_PACKET_IN(D1..Dn)|                 |
       |                 |--------------------->|                 |
       |                 |                      |                 |
       |                 |                      |<Wait for 5 secs>|
       |                 |                      |                 |
       |                 |                      |  <Query for FWD |
       |                 |                      |          entry> |(F1)
       |                 |                      |                 |
       |                 |                      |<Wait for 5 secs>|
       |                 |                      |                 |
       |                 |                      |  <Query for FWD |
       |                 |                      |          entry> |(F2)
       |                 |                      |                 |
       |                 |                      |<Wait for 5 secs>|
       |                 |                      |                 |
       |                 |                      |  <Query for FWD |
       |                 |                      |          entry> |(F3)
       |                 |                      |                 |
       |                 |                      | <Repeat Step 2  |
       |                 |                      |until F1==F2==F3>|
       |                 |                      |                 |

  Legend:

     G-ARP: Gratuitous ARP message
     H1..Hn: Host 1 .. Host n
     FWD: Forwarding Table

  Discussion:

     Query the controller's Forwarding Table entries multiple times,
     until three consecutive queries return the same value.  The last
     value retrieved from the controller will provide the Forwarding
     Table Capacity value.  The query interval is user configurable.
     The interval of 5 seconds shown in this example is for
     representational purposes.




Bhuvaneswaran, et al.         Informational                    [Page 54]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.6.  Security

A.6.1.  Exception Handling

Procedure:

Test Traffic  Test Traffic   Network Devices   OpenFlow          SDN
Generator TP1 Generator TP2                  Controller      Application
  |          |                |                      |                |
  |          |G-ARP (D1..Dn)  |                      |                |
  |          |--------------->|                      |                |
  |          |                |                      |                |
  |          |                |OFPT_PACKET_IN(D1..Dn)|                |
  |          |                |--------------------->|                |
  |          |                |                      |                |
  |Traffic (S1..Sn,D1..Dn)    |                      |                |
  |-------------------------->|                      |                |
  |          |                |                      |                |
  |          |                |OFPT_PACKET_IN(S1..Sa,|                |
  |          |                |               D1..Da)|                |
  |          |                |--------------------->|                |
  |          |                |                      |                |
  |          |                |OFPT_PACKET_IN        |                |
  |          |                |            (Sa+1..Sn,|                |
  |          |                |             Da+1..Dn)|                |
  |          |                |     (1% incorrect OFP|                |
  |          |                |         match header)|                |
  |          |                |--------------------->|                |
  |          |                |                      |                |
  |          |                |      FLOW_MOD(D1..Dn)|                |
  |          |                |<---------------------|                |
  |          |                |                      |                |
  |          |                |      FLOW_MOD(S1..Sa)|                |
  |          |                |           OFP headers|                |
  |          |                |<---------------------|                |
  |          |                |                      |                |
  |          |Traffic (S1..Sa,|                      |                |
  |          |         D1..Da)|                      |                |
  |          |<---------------|                      |                |
  |          |                |                      |                |
  |          |                |                      |   <Wait for the|
  |          |                |                      |   expiry of the|
  |          |                |                      |           Trial|
  |          |                |                      |       Duration>|
  |          |                |                      |                |
  |          |                |                      |      <Record Rx|
  |          |                |                      |       frames at|
  |          |                |                      |      TP2 (Rn1)>|



Bhuvaneswaran, et al.         Informational                    [Page 55]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  |          |                |                      |                |
  |          |                |                      |        <Repeat |
  |          |                |                      |     Step 1 with|
  |          |                |                      |    2% incorrect|
  |          |                |                      |OFPT_PACKET_INs>|
  |          |                |                      |                |
  |          |                |                      |      <Record Rx|
  |          |                |                      |       frames at|
  |          |                |                      |      TP2 (Rn2)>|

  Legend:

     G-ARP: Gratuitous ARP message
     OFPT_PACKET_IN(Sa+1..Sn,Da+1..Dn): OFPT_PACKET_IN with
                                        wrong version number
     Rn1: Total number of frames received at Test Port 2
          with 1% incorrect frames
     Rn2: Total number of frames received at Test Port 2
          with 2% incorrect frames

  Discussion:

     The traffic rate sent towards the OpenFlow switch from Test Port 1
     should be 1% higher than the Path Programming Rate.  Rn1 will
     provide the Path Provisioning Rate of the controller when 1% of
     incorrect frames are received, and Rn2 will provide the Path
     Provisioning Rate of the controller when 2% of incorrect frames
     are received.

     The procedure defined above provides test steps to determine the
     effects of handling error packets on the Path Programming Rate.
     The same procedure can be adapted to determine the effects on
     other performance tests listed in this benchmarking test.


















Bhuvaneswaran, et al.         Informational                    [Page 56]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.6.2.  Handling Denial-of-Service Attacks

Procedure:

Test Traffic  Test Traffic   Network Device      OpenFlow         SDN
Generator TP1 Generator TP2                     Controller  Application
   |          |                 |                      |             |
   |          |G-ARP (D1..Dn)   |                      |             |
   |          |---------------->|                      |             |
   |          |                 |                      |             |
   |          |                 |OFPT_PACKET_IN(D1..Dn)|             |
   |          |                 |--------------------->|             |
   |          |                 |                      |             |
   |Traffic (S1..Sn,D1..Dn)     |                      |             |
   |--------------------------->|                      |             |
   |          |                 |                      |             |
   |          |                 |OFPT_PACKET_IN(S1..Sn,|             |
   |          |                 |               D1..Dn)|             |
   |          |                 |--------------------->|             |
   |          |                 |                      |             |
   |          |                 |TCP SYN attack        |             |
   |          |                 |from a switch         |             |
   |          |                 |--------------------->|             |
   |          |                 |                      |             |
   |          |                 |FLOW_MOD(D1..Dn)      |             |
   |          |                 |<---------------------|             |
   |          |                 |                      |             |
   |          |                 | FLOW_MOD(S1..Sn)     |             |
   |          |                 |      OFP headers     |             |
   |          |                 |<---------------------|             |
   |          |                 |                      |             |
   |          |Traffic (S1..Sn, |                      |             |
   |          |         D1..Dn) |                      |             |
   |          |<----------------|                      |             |
   |          |                 |                      |             |
   |          |                 |                      |<Wait for the|
   |          |                 |                      |expiry of the|
   |          |                 |                      |        Trial|
   |          |                 |                      |    Duration>|
   |          |                 |                      |             |
   |          |                 |                      |   <Record Rx|
   |          |                 |                      |    frames at|
   |          |                 |                      |   TP2 (Rn1)>|
   |          |                 |                      |             |







Bhuvaneswaran, et al.         Informational                    [Page 57]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     G-ARP: Gratuitous ARP message

  Discussion:

     A TCP SYN attack should be launched from one of the
     emulated/simulated OpenFlow switches.  Rn1 provides the Path
     Programming Rate of the controller upon handling a denial-of-
     service attack.

     The procedure defined above provides test steps to determine the
     effects of handling denial of service on the Path Programming
     Rate.  The same procedure can be adapted to determine the effects
     on other performance tests listed in this benchmarking test.




































Bhuvaneswaran, et al.         Informational                    [Page 58]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.7.  Reliability

A.7.1.  Controller Failover Time

Procedure:

Test Traffic  Test Traffic  Network Device       OpenFlow      SDN
Generator TP1 Generator TP2                    Controller   Application
  |            |               |                       |             |
  |            |G-ARP (D1)     |                       |             |
  |            |-------------->|                       |             |
  |            |               |                       |             |
  |            |               |OFPT_PACKET_IN(D1)     |             |
  |            |               |---------------------->|             |
  |            |               |                       |             |
  |Traffic (S1..Sn,D1)         |                       |             |
  |--------------------------->|                       |             |
  |            |               |                       |             |
  |            |               |                       |             |
  |            |               |OFPT_PACKET_IN(S1,D1)  |             |
  |            |               |---------------------->|             |
  |            |               |                       |             |
  |            |               |FLOW_MOD(D1)           |             |
  |            |               |<----------------------|             |
  |            |               |FLOW_MOD(S1)           |             |
  |            |               |<----------------------|             |
  |            |               |                       |             |
  |            |Traffic (S1,D1)|                       |             |
  |            |<--------------|                       |             |
  |            |               |                       |             |
  |            |               |OFPT_PACKET_IN(S2,D1)  |             |
  |            |               |---------------------->|             |
  |            |               |                       |             |
  |            |               |FLOW_MOD(S2)           |             |
  |            |               |<----------------------|             |
  |            |               |                       |             |
  |            |               |OFPT_PACKET_IN         |             |
  |            |               |             (Sn-1,D1) |             |
  |            |               |---------------------->|             |
  |            |               |                       |             |
  |            |               |OFPT_PACKET_IN(Sn,D1)  |             |
  |            |               |---------------------->|             |
  |            |               |          .            |             |
  |            |               |          .            |<Bring down  |
  |            |               |          .            | the active  |
  |            |               |                       | controller> |
  |            |               |  FLOW_MOD(Sn-1)       |             |
  |            |               |    X<-----------------|             |



Bhuvaneswaran, et al.         Informational                    [Page 59]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  |            |               |                       |             |
  |            |               |FLOW_MOD(Sn)           |             |
  |            |               |<----------------------|             |
  |            |               |                       |             |
  |            |Traffic (Sn,D1)|                       |             |
  |            |<--------------|                       |             |
  |            |               |                       |             |
  |            |               |                       |<Stop the    |
  |            |               |                       |test after   |
  |            |               |                       |recv. traffic|
  |            |               |                       |upon         |
  |            |               |                       |failure>     |

  Legend:

     G-ARP: Gratuitous ARP message

  Discussion:

     The time difference between the last valid frame received before
     the traffic loss and the first frame received after the traffic
     loss will provide the Controller Failover Time.

     If there is no frame loss during the Controller Failover Time, the
     Controller Failover Time can be deemed negligible.


























Bhuvaneswaran, et al.         Informational                    [Page 60]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


A.7.2.  Network Re-provisioning Time

Procedure:

Test Traffic  Test Traffic   Network Devices     OpenFlow       SDN
Generator TP1 Generator TP2                     Controller   Application
 |             |                |                      |              |
 |             |G-ARP (D1)      |                      |              |
 |             |--------------->|                      |              |
 |             |                |                      |              |
 |             |                |OFPT_PACKET_IN(D1)    |              |
 |             |                |--------------------->|              |
 |             |G-ARP (S1)      |                      |              |
 |----------------------------->|                      |              |
 |             |                |                      |              |
 |             |                |OFPT_PACKET_IN(S1)    |              |
 |             |                |--------------------->|              |
 |             |                |                      |              |
 |Traffic (S1,D1,Seq. no (1..n))|                      |              |
 |----------------------------->|                      |              |
 |             |                |                      |              |
 |             |                |OFPT_PACKET_IN(S1,D1) |              |
 |             |                |--------------------->|              |
 |             |                |                      |              |
 |             | Traffic (D1,S1,|                      |              |
 |             | Seq. no (1..n))|                      |              |
 |             |--------------->|                      |              |
 |             |                |                      |              |
 |             |                |OFPT_PACKET_IN(D1,S1) |              |
 |             |                |--------------------->|              |
 |             |                |                      |              |
 |             |                |FLOW_MOD(D1)          |              |
 |             |                |<---------------------|              |
 |             |                |                      |              |
 |             |                |FLOW_MOD(S1)          |              |
 |             |                |<---------------------|              |
 |             |                |                      |              |
 |             | Traffic (S1,D1,|                      |              |
 |             |     Seq. no(1))|                      |              |
 |             |<---------------|                      |              |
 |             |                |                      |              |
 |             | Traffic (S1,D1,|                      |              |
 |             |     Seq. no(2))|                      |              |
 |             |<---------------|                      |              |
 |             |                |                      |              |






Bhuvaneswaran, et al.         Informational                    [Page 61]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


 |             |                |                      |              |
 |    Traffic (D1,S1,Seq. no(1))|                      |              |
 |<-----------------------------|                      |              |
 |             |                |                      |              |
 |    Traffic (D1,S1,Seq. no(2))|                      |              |
 |<-----------------------------|                      |              |
 |             |                |                      |              |
 |    Traffic (D1,S1,Seq. no(x))|                      |              |
 |<-----------------------------|                      |              |
 |             |                |                      |              |
 |             | Traffic (S1,D1,|                      |              |
 |             |     Seq. no(x))|                      |              |
 |             |<---------------|                      |              |
 |             |                |                      |              |
 |             |                |                      |              |
 |             |                |                      |  <Bring down |
 |             |                |                      | the switch in|
 |             |                |                      |    the active|
 |             |                |                      | traffic path>|
 |             |                |                      |              |
 |             |                |PORT_STATUS(Sa)       |              |
 |             |                |--------------------->|              |
 |             |                |                      |              |
 |             | Traffic (S1,D1,|                      |              |
 |             | Seq. no(n - 1))|                      |              |
 |             |  X<------------|                      |              |
 |             |                |                      |              |
 |Traffic (D1,S1,Seq. no(n - 1))|                      |              |
 |    X<------------------------|                      |              |
 |             |                |                      |              |
 |             |                |                      |              |
 |             |                |FLOW_MOD(D1)          |              |
 |             |                |<---------------------|              |
 |             |                |                      |              |
 |             |                |FLOW_MOD(S1)          |              |
 |             |                |<---------------------|              |
 |             |                |                      |              |
 |    Traffic (D1,S1,Seq. no(n))|                      |              |
 |<-----------------------------|                      |              |
 |             |                |                      |              |
 |             | Traffic (S1,D1,|                      |              |
 |             |     Seq. no(n))|                      |              |
 |             |<---------------|                      |              |
 |             |                |                      |              |
 |             |                |                      |<Stop the test|
 |             |                |                      |  after recv. |
 |             |                |                      |  traffic upon|
 |             |                |                      |   failover>  |



Bhuvaneswaran, et al.         Informational                    [Page 62]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


  Legend:

     G-ARP: Gratuitous ARP message
     Seq. no: Sequence number
     Sa: Neighbor switch of the switch that was brought down

  Discussion:

     The time difference between the last valid frame received before
     the traffic loss (packet with sequence number x) and the first
     frame received after the traffic loss (packet with sequence
     number n) will provide the Network Re-provisioning Time.

     Note that the trial is valid only when the controller provisions
     the alternate path upon network failure.

Acknowledgments

  The authors would like to thank the following individuals for
  providing their valuable comments regarding the earlier draft
  versions of this document: Al Morton (AT&T), Sandeep Gangadharan
  (HP), M. Georgescu (NAIST), Andrew McGregor (Google), Scott Bradner,
  Jay Karthik (Cisco), Ramki Krishnan (VMware), Boris Khasanov
  (Huawei), and Brian Castelli (Spirent).



























Bhuvaneswaran, et al.         Informational                    [Page 63]

RFC 8456         SDN Controller Benchmarking Methodology    October 2018


Authors' Addresses

  Bhuvaneswaran Vengainathan
  Veryx Technologies Inc.
  1 International Plaza, Suite 550
  Philadelphia, PA  19113
  United States of America

  Email: [email protected]


  Anton Basil
  Veryx Technologies Inc.
  1 International Plaza, Suite 550
  Philadelphia, PA  19113
  United States of America

  Email: [email protected]


  Mark Tassinari
  Hewlett Packard Enterprise
  8000 Foothills Blvd.
  Roseville, CA  95747
  United States of America

  Email: [email protected]


  Vishwas Manral
  NanoSec Co
  3350 Thomas Rd.
  Santa Clara, CA  95054
  United States of America

  Email: [email protected]


  Sarah Banks
  VSS Monitoring
  930 De Guigne Drive
  Sunnyvale, CA  94085
  United States of America

  Email: [email protected]






Bhuvaneswaran, et al.         Informational                    [Page 64]