RFC 8455
Terminology for Benchmarking Software-Defined Networking (SDN) Controller Performance
Pages: 23
Informational
Informational
Internet Engineering Task Force (IETF) V. Bhuvaneswaran Request for Comments: 8455 A. Basil Category: Informational Veryx Technologies ISSN: 2070-1721 M. Tassinari Hewlett Packard Enterprise V. Manral NanoSec S. Banks VSS Monitoring October 2018 Terminology for Benchmarking Software-Defined Networking (SDN) Controller PerformanceAbstract
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. The terms provided in this document help to benchmark an SDN 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.
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 ....................................................3 1.1. Conventions Used in This Document ..........................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. Handling 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. Normative References ...........................................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. The SDN 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 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 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 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/A2.1.2. 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. Measurement Units: N/A
2.1.3. Southbound Interface
Definition: The southbound interface is the application programming interface provided by the SDN 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/A2.1.4. Controller Forwarding Table
Definition: A controller 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 has an aging mechanism that will be applied only for dynamically learned entries. Measurement Units: N/A2.1.5. 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. 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 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/A2.1.7. Path
Definition: Refer to Section 5 in [RFC2330]. Discussion: None Measurement Units: N/A2.1.8. Standalone Mode
Definition: A single controller handles all control-plane functionalities without redundancy, 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/A2.1.10. 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/A2.1.11. 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/A2.2. 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.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. 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 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 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 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 Asynchronous Message Processing
Rate and the Maximum 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. 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 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
Asynchronous Message Processing Rate and the Maximum 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 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 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 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, 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 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 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.
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 the Reactive Flow
Provisioning mode or the Proactive Flow Provisioning mode until
the 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. 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 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
+-------------------------------------------------------------------+ | Lifecycle | Speed | Scalability | Reliability | +------------+-------------------+---------------+------------------+ | | 1. Network |1. Network | | | | Topology | Discovery | | | | Discovery | Size | | | | Time | | | | | | | | | | 2. Reactive Path | | | | | Provisioning | | | | | Time | | | | | | | | | | 3. Proactive Path | | | | Setup | Provisioning | | | | | Time | | | | | | | | | | 4. Reactive Path | | | | | Provisioning | | | | | Rate | | | | | | | | | | 5. Proactive Path | | | | | Provisioning | | | | | Rate | | | | | | | | +------------+-------------------+---------------+------------------+ | | 1. Maximum |1. Control |1. Network | | | Asynchronous | Sessions | Topology | | | Message | Capacity | Change | | | Processing Rate| | Detection Time | | | |2. Forwarding | | | | 2. Loss-Free | Table |2. Exception | | | Asynchronous | Capacity | Handling | | | Message | | | | Operational| Processing Rate| |3. Handling | | | | | Denial-of- | | | 3. Asynchronous | | Service Attacks| | | Message | | | | | Processing Time| |4. Network | | | | | Re-provisioning| | | | | Time | | | | | | +------------+-------------------+---------------+------------------+ | Teardown | | |1. Controller | | | | | Failover Time | +------------+-------------------+---------------+------------------+
5. IANA Considerations
This document has no IANA actions.6. 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.7. 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>. [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, "Framework for IP Performance Metrics", RFC 2330, DOI 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>. [RFC7426] Haleplidis, E., Ed., Pentikousis, K., Ed., Denazis, S., Hadi Salim, J., Meyer, D., and O. Koufopavlou, "Software- Defined Networking (SDN): Layers and Architecture Terminology", RFC 7426, DOI 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] 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, October 2018, <https://www.rfc-editor.org/info/rfc8456>.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), Ramki Krishnan (VMware), and Boris Khasanov (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 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