| Rfc | 8456 |
|---|
| Title | Benchmarking Methodology for Software-Defined Networking (SDN)
Controller Performance |
|---|
| Author | V. Bhuvaneswaran, A. Basil, M. Tassinari, V.
Manral, S. Banks |
|---|
| Date | October 2018 |
|---|
| Format: | TXT, HTML |
|---|
| Status: | INFORMATIONAL |
|---|
|
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.
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
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
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.
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 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.
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.
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
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.
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).
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.
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
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
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.
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.
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.
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
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).
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
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).
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
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).
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
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).
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
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.
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.
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).
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)
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.
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.
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.
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.
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
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).
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.
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>.
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.
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>|
| | |
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.
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.
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%).
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)|<---------------------| |
| | | |
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).
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).
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)| |
| |<-------------------| |
| | | |
| | | |
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.
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)|<---------------| | |
| | | | |
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.
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.
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> |
| | |
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.
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.
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)>|
| | | | |
| | | | <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.
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)>|
| | | | |
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.
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<-----------------| |
| | | | |
| | |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.
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))| | |
| |<---------------| | |
| | | | |
| | | | |
| 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> |
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).
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