wdiff rfc8455v1.txt rfc8455.txt

Internet Engineering Task Force (IETF) B. Vengainathan V. Bhuvaneswaran
Request for Comments: 8455 A. Basil
Category: Informational Veryx Technologies
ISSN: 2070-1721 M. Tassinari
Hewlett-Packard
Hewlett Packard Enterprise
V. Manral
NanoSec
S. Banks
VSS Monitoring
September
October 2018

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

Abstract

This document defines terminology for benchmarking a Software-Defined
Networking (SDN) controller's control-plane performance. It extends
the terminology already defined in RFC 7426 for the purpose of
benchmarking SDN controllers. Controllers. The terms provided in this document
help to benchmark an SDN controller's Controller's performance independently of
the controller's supported protocols and/or network services.

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/rfc8455.

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 ....................................................3
1.1. Conventions Used in This Document ..........................4 ..........................3
2. Term Definitions ................................................4
2.1. SDN Terms ..................................................4
2.1.1. Flow ................................................4
2.1.2. Northbound Interface ................................4
2.1.3. Southbound Interface ................................5
2.1.4. Controller Forwarding Table .........................5
2.1.5. Proactive Flow Provisioning Mode ....................5
2.1.6. Reactive Flow Provisioning Mode .....................6
2.1.7. Path ................................................6
2.1.8. Standalone Mode .....................................6
2.1.9. Cluster/Redundancy Mode .............................7
2.1.10. Asynchronous Message ...............................7
2.1.11. Test Traffic Generator .............................7
2.1.12. Leaf-Spine Topology ................................8
2.2. Test Configuration/Setup Terms .............................8
2.2.1. Number of Network Devices ...........................8
2.2.2. Trial Repetition ....................................8
2.2.3. Trial Duration ......................................9
2.2.4. Number of Cluster Nodes .............................9
2.3. Benchmarking Terms .........................................9
2.3.1. Performance .........................................9
2.3.1.1. Network Topology Discovery Time ............9
2.3.1.2. Asynchronous Message Processing Time ......10
2.3.1.3. Asynchronous Message Processing Rate ......10
2.3.1.4. Reactive Path Provisioning Time ...........11
2.3.1.5. Proactive Path Provisioning Time ..........12
2.3.1.6. Reactive Path Provisioning Rate ...........12
2.3.1.7. Proactive Path Provisioning Rate ..........13
2.3.1.8. Network Topology Change Detection Time ....13
2.3.2. Scalability ........................................14
2.3.2.1. Control Sessions Capacity .................14
2.3.2.2. Network Discovery Size ....................14
2.3.2.3. Forwarding Table Capacity .................15
2.3.3. Security ...........................................15
2.3.3.1. Exception Handling ........................15
2.3.3.2. Denial-of-Service Handling ................16 Denial-of-Service Attacks ........16
2.3.4. Reliability ........................................16
2.3.4.1. Controller Failover Time ..................16
2.3.4.2. Network Re-provisioning Time ..............17
3. Test Setup .....................................................17
3.1. Test Setup - Controller Operating in Standalone Mode ......18
3.2. Test Setup - Controller Operating in Cluster Mode .........19
4. Test Coverage ..................................................20
5. IANA Considerations ............................................21
6. Security Considerations ........................................21
7. References .....................................................21
7.1. Normative References ......................................21
7.2. Informative References ....................................22 ...........................................21
Acknowledgments ...................................................22
Authors' Addresses ................................................23

1. Introduction

Software-Defined Networking (SDN) is a networking architecture in
which network control is decoupled from the underlying forwarding
function and is placed in a centralized location called the SDN
controller.
Controller. The SDN controller Controller provides an abstraction of the
underlying network and offers a global view of the overall network to
applications and business logic. Thus, an SDN controller Controller provides
the flexibility to program, control, and manage network behavior
dynamically through northbound and southbound interfaces. Since the
network controls are logically centralized, the need to benchmark the
SDN controller's Controller's performance becomes significant. This document
defines terms to benchmark various controller designs for
performance, scalability, reliability, and security, independently of
northbound and southbound protocols. A mechanism for benchmarking
the performance of SDN controllers Controllers is defined in the companion
methodology document [RFC8456]. These two documents provide methods
for measuring and evaluating the performance of various controller
implementations.

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. Term Definitions

2.1. SDN Terms

The terms defined in this section are extensions to the terms defined
in [RFC7426] ("Software-Defined Networking (SDN): Layers and
Architecture Terminology"). Readers should refer to [RFC7426] before
attempting to make use of this document.

2.1.1. Flow

Definition:
The definition of "flow" is the same as the definition of
"microflows" provided in Section 3.1.5 of [RFC4689].

Discussion:
A flow can be a set of packets having the same source address,
destination address, source port, and destination port, or any
combination of these items.

Measurement Units:
N/A

2.1.2. Northbound Interface

Definition:
The definition of "northbound interface" is the same as the
definition of "service interface" provided in [RFC7426].

Discussion:
The northbound interface allows SDN applications and orchestration
systems to program and retrieve the network information through
the SDN controller. Controller.

Measurement Units:
N/A

2.1.3. Southbound Interface

Definition:
The southbound interface is the application programming interface
provided by the SDN controller Controller to interact with the SDN nodes.

Discussion:
The southbound interface enables the controller to interact with
the SDN nodes in the network for dynamically defining the traffic
forwarding behavior.

Measurement Units:
N/A

2.1.4. Controller Forwarding Table

Definition:
A controller forwarding table Forwarding Table contains flow entries learned in one
of two ways: first, entries can be learned from traffic received
through the data plane, or second, these entries can be statically
provisioned on the controller and distributed to devices via the
southbound interface.

Discussion:
The controller forwarding table Forwarding Table has an aging mechanism that will
be applied only for dynamically learned entries.

Measurement Units:
N/A

2.1.5. Proactive Flow Provisioning Mode

Definition:
Controller programming flows in Network Devices based on the flow
entries provisioned through the controller's northbound interface.

Discussion:
Network orchestration systems and SDN applications can define the
network forwarding behavior by programming the controller, using
proactive flow provisioning.
Proactive Flow Provisioning. The controller can then program the
Network Devices with the pre-provisioned entries.

Measurement Units:
N/A

2.1.6. Reactive Flow Provisioning Mode

Definition:
Controller programming flows in Network Devices based on the
traffic received from Network Devices through the controller's
southbound interface.

Discussion:
The SDN controller Controller dynamically decides the forwarding behavior
based on the incoming traffic from the Network Devices. The
controller then programs the Network Devices, using Reactive Flow
Provisioning.

Measurement Units:
N/A

2.1.7. Path

Definition:
Refer to Section 5 in [RFC2330].

Discussion:
None

Measurement Units:
N/A

2.1.8. Standalone Mode

Definition:
A single controller handling handles all control-plane functionalities
without redundancy, or the ability and it is unable to provide high availability
and/or automatic failover.

Discussion:
In standalone mode, one controller manages one or more network
domains.

Measurement Units:
N/A

2.1.9. Cluster/Redundancy Mode

Definition:
In this mode, a group of two or more controllers handles all
control-plane functionalities.

Discussion:
In cluster mode, multiple controllers are teamed together for the
purpose of load sharing and/or high availability. The controllers
in the group may operate in active/standby (master/slave) or
active/active (equal) mode, depending on the intended purpose.

Measurement Units:
N/A

2.1.10. Asynchronous Message

Definition:
Any message from the Network Device that is generated for network
events.

Discussion:
Control messages like flow setup request and response messages are
classified as asynchronous messages. The controller has to return
a response message. Note that the Network Device will not be in
blocking mode and continues to send/receive other control
messages.

Measurement Units:
N/A

2.1.11. Test Traffic Generator

Definition:
The test traffic generator is an entity that generates/receives
network traffic.

Discussion:
The test traffic generator typically connects with Network Devices
to send/receive real-time network traffic.

Measurement Units:
N/A

2.1.12. Leaf-Spine Topology

Definition:
"Leaf-Spine" is a two-layered network topology, where a series of
leaf switches that form the access layer are fully meshed to a
series of spine switches that form the backbone layer.

Discussion:
In the Leaf-Spine topology, every leaf switch is connected to each
of the spine switches in the topology.

Measurement Units:
N/A

2.2. Test Configuration/Setup Terms

2.2.1. Number of Network Devices

Definition:
The number of Network Devices present in the defined test
topology.

Discussion:
The Network Devices defined in the test topology can be deployed
using real hardware or can be emulated in hardware platforms.

Measurement Units:
Number of network devices. Network Devices.

2.2.2. Trial Repetition

Definition:
The number of times the test needs to be repeated.

Discussion:
The test needs to be repeated for multiple iterations to obtain a
reliable metric. It is recommended that this test SHOULD be
performed for at least 10 iterations to increase confidence in the
measured results.

Measurement Units:
Number of trials.

2.2.3. Trial Duration

Definition:
Defines the duration of test trials for each iteration.

Discussion:
The Trial Duration forms the basis for "stop" criteria for
benchmarking tests. Trials not completed within this time
interval are considered incomplete.

Measurement Units:
Seconds.

2.2.4. Number of Cluster Nodes

Definition:
Defines the number of controllers present in the controller
cluster.

Discussion:
This parameter is relevant when testing the controller's
performance in clustering/teaming mode. The number of nodes in
the cluster MUST be greater than 1.

Measurement Units:
Number of controller nodes.

2.3. Benchmarking Terms

This section defines metrics for benchmarking the SDN controller. Controller.
The procedure for performing the defined metrics is defined in the
companion methodology document [RFC8456].

2.3.1. Performance

2.3.1.1. Network Topology Discovery Time

Definition:
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.

Discussion:
Network topology discovery is key for the SDN controller Controller to
provision and manage the network, so it is important to measure
how quickly the controller discovers the topology to learn the
current network state. This benchmark is obtained by presenting a
network topology (tree, mesh, or linear) with a specified number
of nodes to the controller and waiting for the discovery process
to complete. It is expected that the controller supports a
network discovery mechanism and uses protocol messages for its
discovery process.

Measurement Units:
Milliseconds.

2.3.1.2. Asynchronous Message Processing Time

Definition:
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 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.

Discussion:
For SDN to support dynamic network provisioning, it is important
to measure how quickly the controller responds to an event
triggered from the network. The event can be any notification
messages generated by a Network Device upon arrival of a new flow,
link down, etc. This benchmark is obtained by sending
asynchronous messages from every connected Network Device one at a
time for the defined Trial Duration. This test assumes that the
controller will respond to the received asynchronous messages.

Measurement Units:
Milliseconds.

2.3.1.3. Asynchronous Message Processing Rate

Definition:
The number of responses to asynchronous messages per second (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.

Discussion:
As SDN assures a flexible network and agile provisioning, it is
important to measure how many network events (a new flow arrival
notification message, link down, etc.) the controller can handle
at a time. This benchmark is measured by sending asynchronous
messages from every connected Network Device at the rate that the
controller processes (without dropping them). This test assumes
that the controller responds to all the received asynchronous
messages (the messages can be designed to elicit individual
responses).

When sending asynchronous messages to the controller(s) at high
rates, some messages or responses may be discarded or corrupted
and require retransmission to controller(s). Therefore, a useful
qualification on the Asynchronous Message Processing Rate is
whether the incoming message count equals the response count in
each trial. This is called the Loss-free Loss-Free Asynchronous Message
Processing Rate.

Note that several of the early controller benchmarking tools did
not consider lost messages and instead report the maximum response
rate. This is called the Maximum Asynchronous Message Processing
Rate.

To characterize both the Loss-free Loss-Free Asynchronous Message Processing
Rate and the Maximum Rates, Asynchronous Message Processing Rate, a test
can begin the first trial by sending asynchronous messages to the
controller(s) at the maximum possible rate and can then record the
message reply rate and the message loss rate. The message-sending
rate is then decreased by the step-size. STEP size. The message reply rate
and the message loss rate are recorded. The test ends with a
trial where the controller(s) processes all of the asynchronous
messages sent without loss. This is the Loss-free Loss-Free Asynchronous
Message Processing Rate.

The trial where the controller(s) produced the maximum response
rate is the Maximum Asynchronous Message Processing Rate. Of
course, the first trial can begin at a low sending rate with zero
lost responses and then increase the rate until the Loss-free Loss-Free
Asynchronous Message Processing Rate and the Maximum Rates Asynchronous
Message Processing Rate are discovered.

Measurement Units:
Messages processed per second.

2.3.1.4. Reactive Path Provisioning Time

Definition:
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) and ending with the last flow provisioning
response message sent from the controller(s) at its southbound
interface.

Discussion:
As SDN supports agile provisioning, it is important to measure how
fast the controller provisions an end-to-end flow in the
data plane. The benchmark is obtained by sending traffic from a
source endpoint to the destination endpoint and finding the time
difference between the first and last flow provisioning message
exchanged between the controller and the Network Devices for the
traffic path.

Measurement Units:
Milliseconds.

2.3.1.5. Proactive Path Provisioning Time

Definition:
The time taken by the controller to proactively set up a path
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 command message sent from the controller(s) at
its southbound interface.

Discussion:
For SDN to support pre-provisioning of the traffic path from the
application, it is important to measure how fast the controller
provisions an end-to-end flow in the data plane. The benchmark is
obtained by provisioning a flow on the controller's northbound
interface for the traffic to reach from a source to a destination
endpoint and finding the time difference between the first and
last flow provisioning message exchanged between the controller
and the Network Devices for the traffic path.

Measurement Units:
Milliseconds.

2.3.1.6. Reactive Path Provisioning Rate

Definition:
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 trial and the expiry
of the given Trial Duration.

Discussion:
For SDN to support agile traffic forwarding, it is important to
measure how many end-to-end flows the controller can set up in the
data plane. This benchmark is obtained by sending traffic each traffic
flow with unique source and destination pairs from the source
Network Device and determining the number of frames received at
the destination Network Device.

Measurement Units:
Paths provisioned per second.

2.3.1.7. Proactive Path Provisioning Rate

Definition:
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 provisioned in its northbound interface between the start of
the trial and the expiry of the given Trial Duration.

Discussion:
For SDN to support pre-provisioning of the traffic path for a
larger network from the application, it is important to measure
how many end-to-end flows the controller can set up in the
data plane. This benchmark is obtained by sending traffic each traffic
flow with unique source and destination pairs from the source
Network Device. Program the flows on the controller's northbound
interface for traffic to reach from each of the unique source and
destination pairs, and determine the number of frames received at
the destination Network Device.

Measurement Units:
Paths provisioned per second.

2.3.1.8. Network Topology Change Detection Time

Definition:
The amount of time required for 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 messages sent from the controller(s) at its southbound
interface.

Discussion:
In order for the controller to support fast network failure
recovery, it is critical to measure how fast the controller is
able to detect any network-state change events. This benchmark is
obtained by triggering a topology change event and measuring the
time the controller takes to detect and initiate a topology
rediscovery process.

Measurement Units:
Milliseconds.

2.3.2. Scalability

2.3.2.1. Control Sessions Capacity

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

Discussion:
Measuring the controller's control sessions capacity Control Sessions Capacity is important
for determining the controller's system and bandwidth resource
requirements. This benchmark is obtained by establishing a
control session with the controller from each of the Network
Devices until the controller fails. The number of sessions that
were successfully established will provide the Control Sessions
Capacity.

Measurement Units:
Maximum number of control sessions.

2.3.2.2. Network Discovery Size

Definition:
The network size (number of nodes and links) 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 topology number of nodes and links
that the controller(s) can successfully discover.

Discussion:
Measuring the maximum network size that the controller can
discover is key to optimal network planning. This benchmark is
obtained by presenting an initial set of Network Devices for
discovery to the controller. Based on the initial discovery, the
number of Network Devices is increased or decreased to determine
the maximum number of nodes and links that the controller can
discover.

Measurement Units:
Maximum number of network nodes and links.

2.3.2.3. Forwarding Table Capacity

Definition:
The maximum number of flow entries that a controller can manage in
its Forwarding table. Table.

Discussion:
It is important to measure the capacity of a controller's
Forwarding Table to determine the number of flows that the
controller can forward without flooding or dropping any traffic.
This benchmark is obtained by continuously presenting the
controller with new flow entries through reactive the Reactive Flow
Provisioning mode or proactive
flow provisioning the Proactive Flow Provisioning mode until
the forwarding table Forwarding Table becomes full. The maximum number of nodes
that the controller can hold in its Forwarding Table will provide
the Forwarding Table Capacity.

Measurement Units:
Maximum number of flow entries managed.

2.3.3. Security

2.3.3.1. Exception Handling

Definition:
To determine the effect of handling error packets and
notifications on performance tests.

Discussion:
This benchmark is to be performed after obtaining the baseline
measurement results for the performance tests defined in
Section 2.3.1. This benchmark determines the deviation from the
baseline performance due to the handling of error or failure
messages from the connected Network Devices.

Measurement Units:
Deviation from baseline metrics while handling Exceptions.

2.3.3.2. Denial-of-Service Handling Denial-of-Service Attacks

Definition:
To determine the effect of handling denial-of-service (DoS)
attacks on performance and scalability tests.

Discussion:
This benchmark is to be performed after obtaining the baseline
measurement results for the performance and scalability tests
defined in Sections 2.3.1 and 2.3.2. This benchmark determines
the deviation from the baseline performance due to the handling of
DoS attacks on the controller.

Measurement Units:
Deviation from baseline metrics while handling DoS attacks.

2.3.4. Reliability

2.3.4.1. Controller Failover Time

Definition:
The time taken to switch from an active controller to the backup
controller when the controllers operate 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.

Discussion:
This benchmark determines the impact of provisioning new flows
when controllers are teamed together and the active controller
fails.

Measurement Units:
Milliseconds.

2.3.4.2. Network Re-provisioning Time

Definition:
The time required for 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.

Discussion:
This benchmark determines the controller's re-provisioning ability
upon network failures and makes the following assumptions:

1. The network topology supports a redundant path between the
source and destination endpoints.

2. The controller does not pre-provision the redundant path.

Measurement Units:
Milliseconds.

3. Test Setup

This section provides common reference topologies that are referred
to in individual tests defined in the companion methodology document
[RFC8456].

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

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

4. Test Coverage

5. IANA Considerations

This document has no IANA actions.

6. Security Considerations

Security issues are not discussed

The benchmarking tests described in this memo. 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.

7. References

7.1. Normative References

[RFC7426] Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis,

[RFC2119] Bradner, S.,
Hadi Salim, "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>.

[RFC2330] Paxson, V., Almes, G., Mahdavi, J., Meyer, D., and O. Koufopavlou, "Software-
Defined Networking (SDN): Layers and Architecture
Terminology", M. Mathis,
"Framework for IP Performance Metrics", RFC 7426, 2330,
DOI 10.17487/RFC7426,
January 2015, <https://www.rfc-editor.org/info/rfc7426>. 10.17487/RFC2330, May 1998,
<https://www.rfc-editor.org/info/rfc2330>.

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

[RFC2330] Paxson, V., Almes, G., Mahdavi,

[RFC7426] Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S.,
Hadi Salim, J., Meyer, D., and M. Mathis,
"Framework for IP Performance Metrics", RFC 2330,
DOI 10.17487/RFC2330, May 1998,
<https://www.rfc-editor.org/info/rfc2330>.

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, O. Koufopavlou, "Software-
Defined Networking (SDN): Layers and Architecture
Terminology", RFC 2119, 7426, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. 10.17487/RFC7426,
January 2015, <https://www.rfc-editor.org/info/rfc7426>.

[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>.

[RFC8456] Vengainathan, B., Bhuvaneswaran, V., Basil, A., Tassinari, M., Manral, V.,
and S. Banks, "Benchmarking Methodology for Software-
Defined Networking (SDN) Controller Performance",
RFC 8456, DOI 10.17487/RFC8456, September October 2018,
<https://www.rfc-editor.org/info/rfc8456>.

7.2. 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>.

Acknowledgments

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

Authors' Addresses

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

Email: bhuvaneswaran.vengainathan@veryxtech.com

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

Email: anton.basil@veryxtech.com

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

Email: mark.tassinari@hpe.com

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

Email: vishwas.manral@gmail.com

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

Email: sbanks@encrypted.net