Benchmarking Methodology Working Group C. Davids
Internet-Draft Illinois Institute of Technology
Intended status: Informational V. Gurbani
Expires: August 18, 2014 Bell Laboratories,
Alcatel-Lucent
S. Poretsky
Allot Communications
February 14, 2014
Methodology for Benchmarking Session Initiation Protocol (SIP) Devices:
Basic session setup and registration
draft-ietf-bmwg-sip-bench-meth-09
Abstract
This document provides a methodology for benchmarking the Session
Initiation Protocol (SIP) performance of devices. Terminology
related to benchmarking SIP devices is described in the companion
terminology document. Using these two documents, benchmarks can be
obtained and compared for different types of devices such as SIP
Proxy Servers, Registrars and Session Border Controllers. The term
"performance" in this context means the capacity of the device-under-
test (DUT) to process SIP messages. Media streams are used only to
study how they impact the signaling behavior. The intent of the two
documents is to provide a normalized set of tests that will enable an
objective comparison of the capacity of SIP devices. Test setup
parameters and a methodology is necessary because SIP allows a wide
range of configuration and operational conditions that can influence
performance benchmark measurements. A standard terminology and
methodology will ensure that benchmarks have consistent definition
and were obtained following the same procedures.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
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This Internet-Draft will expire on August 18, 2014.
Copyright Notice
Copyright (c) 2014 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
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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.
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Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Benchmarking Topologies . . . . . . . . . . . . . . . . . . . 5
4. Test Setup Parameters . . . . . . . . . . . . . . . . . . . . 6
4.1. Selection of SIP Transport Protocol . . . . . . . . . . . 6
4.2. Signaling Server . . . . . . . . . . . . . . . . . . . . . 6
4.3. Associated Media . . . . . . . . . . . . . . . . . . . . . 7
4.4. Selection of Associated Media Protocol . . . . . . . . . . 7
4.5. Number of Associated Media Streams per SIP Session . . . . 7
4.6. Session Duration . . . . . . . . . . . . . . . . . . . . . 7
4.7. Attempted Sessions per Second . . . . . . . . . . . . . . 7
4.8. Benchmarking algorithm . . . . . . . . . . . . . . . . . . 7
5. Reporting Format . . . . . . . . . . . . . . . . . . . . . . . 10
5.1. Test Setup Report . . . . . . . . . . . . . . . . . . . . 10
5.2. Device Benchmarks for IS . . . . . . . . . . . . . . . . . 10
5.3. Device Benchmarks for NS . . . . . . . . . . . . . . . . . 10
6. Test Cases . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6.1. Baseline Session Establishment Rate of the test bed . . . 11
6.2. Session Establishment Rate without media . . . . . . . . . 11
6.3. Session Establishment Rate with Media not on DUT . . . . . 11
6.4. Session Establishment Rate with Media on DUT . . . . . . . 12
6.5. Session Establishment Rate with TLS Encrypted SIP . . . . 12
6.6. Session Establishment Rate with IPsec Encrypted SIP . . . 13
6.7. Registration Rate . . . . . . . . . . . . . . . . . . . . 13
6.8. Re-Registration Rate . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT
RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as
described in BCP 14, conforming to [RFC2119] and indicate requirement
levels for compliant implementations.
RFC 2119 defines the use of these key words to help make the intent
of standards track documents as clear as possible. While this
document uses these keywords, this document is not a standards track
document. The term Throughput is defined in [RFC2544].
Terms specific to SIP [RFC3261] performance benchmarking are defined
in [I-D.sip-bench-term].
2. Introduction
This document describes the methodology for benchmarking Session
Initiation Protocol (SIP) performance as described in Terminology
document [I-D.sip-bench-term]. The methodology and terminology are
to be used for benchmarking signaling plane performance with varying
signaling and media load. Media streams, when used, are used only to
study how they impact the signaling behavior. This document
concentrates on benchmarking SIP session setup and SIP registrations
only.
The device-under-test (DUT) is a SIP server, which may be any SIP
conforming [RFC3261] device. Benchmarks can be obtained and compared
for different types of devices such as SIP Proxy Server, Session
Border Controllers (SBC), SIP registrars and SIP proxy server paired
with a media relay.
The test cases provide metrics for benchmarking the maximum 'SIP
Registration Rate' and maximum 'SIP Session Establishment Rate' that
the DUT can sustain over an extended period of time without failures.
Some cases are included to cover Encrypted SIP. The test topologies
that can be used are described in the Test Setup section. Topologies
in which the DUT handles media as well as those in which the DUT does
not handle media are both considered. The measurement of the
performance characteristics of the media itself is outside the scope
of these documents.
SIP permits a wide range of configuration options that are explained
in Section 4 and Section 2 of [I-D.sip-bench-term]. Benchmark values
could possibly be impacted by Associated Media. The selected values
for Session Duration and Media Streams per Session enable benchmark
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metrics to be evaluated without Associated Media. Session
Establishment Rate could possibly be impacted by the selected value
for Maximum Sessions Attempted. The benchmark for Session
Establishment Rate is measured with a fixed value for maximum Session
Attempts.
SIP permits a wide range of configuration options that are explained
in Section 4 and Section 2 of [I-D.sip-bench-term]. Benchmark
metrics could possibly be impacted by Associated Media. The selected
values for Session Duration and Media Streams per Session enable
benchmark metrics to be benchmarked without Associated Media.
Session Setup Rate could possibly be impacted by the selected value
for Maximum Sessions Attempted. The benchmark for Session
Establishment Rate is measured with a fixed value for maximum Session
Attempts.
Finally, the overall value of these tests is to serve as a comparison
function between multiple SIP implementations. One way to use these
tests is to derive benchmarks with SIP devices from Vendor-A, derive
a new set of benchmarks with similar SIP devices from Vendor-B and
perform a comparison on the results of Vendor-A and Vendor-B. This
document does not make any claims on the interpretation of such
results.
3. Benchmarking Topologies
There are two test topologies; one in which the DUT does not process
the media (Figure 1) and the other in which it does process media
(Figure 2). In both cases, the tester or EA sends traffic into the
DUT and absorbs traffic from the DUT. The diagrams in Figure 1 and
Figure 2 represent the logical flow of information and do not dictate
a particular physical arrangements of the entities.
Test organizations need to be aware that these tests generate large
volumes of data and consequently ensure that networking devices like
hubs, switches or routers are able to handle the generated volume.
Figure 1 depicts a layout in which the DUT as an intermediary between
the two interfaces of the EA. If the test case requires the exchange
of media, the media does not flow through the DUT but rather passes
directly between the two endpoints. Figure 2 shows the DUT as an
intermediary between the two interfaces of the EA. If the test case
requires the exchange of media, the media flows through the DUT
between the endpoints.
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+--------+ Session +--------+ Session +--------+
| | Attempt | | Attempt | |
| |------------>+ |------------>+ |
| | | | | |
| | Response | | Response | |
| Tester +<------------| DUT +<------------| Tester |
| (EA) | | | | (EA) |
| | | | | |
+--------+ +--------+ +--------+
/|\ /|\
| Media (optional) |
+==============================================+
Figure 1: DUT as an intermediary, end-to-end media
+--------+ Session +--------+ Session +--------+
| | Attempt | | Attempt | |
| |------------>+ |------------>+ |
| | | | | |
| | Response | | Response | |
| Tester +<------------| DUT +<------------| Tester |
| (EA) | | | | (EA) |
| |<===========>| |<===========>| |
+--------+ Media +--------+ Media +--------+
(Optional) (Optional)
Figure 2: DUT as an intermediary forwarding media
4. Test Setup Parameters
4.1. Selection of SIP Transport Protocol
Test cases may be performed with any transport protocol supported by
SIP. This includes, but is not limited to, TCP, UDP, TLS and
websockets. The protocol used for the SIP transport protocol must be
reported with benchmarking results.
4.2. Signaling Server
The Signaling Server is defined in the companion terminology
document, ([I-D.sip-bench-term], Section 3.2.2). The Signaling
Server is a DUT.
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4.3. Associated Media
Some tests require Associated Media to be present for each SIP
session. The test topologies to be used when benchmarking DUT
performance for Associated Media are shown in Figure 1 and Figure 2.
4.4. Selection of Associated Media Protocol
The test cases specified in this document provide SIP performance
independent of the protocol used for the media stream. Any media
protocol supported by SIP may be used. This includes, but is not
limited to, RTP, RTSP, and SRTP. The protocol used for Associated
Media MUST be reported with benchmarking results.
4.5. Number of Associated Media Streams per SIP Session
Benchmarking results may vary with the number of media streams per
SIP session. When benchmarking a DUT for voice, a single media
stream is used. When benchmarking a DUT for voice and video, two
media streams are used. The number of Associated Media Streams MUST
be reported with benchmarking results.
4.6. Session Duration
The value of the DUT's performance benchmarks may vary with the
duration of SIP sessions. Session Duration MUST be reported with
benchmarking results. A Session Duration of zero seconds indicates
transmission of a BYE immediately following successful SIP
establishment indicate by receipt of a 200 OK. An infinite Session
Duration indicates that a BYE is never transmitted.
4.7. Attempted Sessions per Second
The value of the DUT's performance benchmarks may vary with the
Session Attempt Rate offered by the tester. Session Attempt Rate
MUST be reported with the benchmarking results.
4.8. Benchmarking algorithm
In order to benchmark the test cases uniformly in Section 6, the
algorithm described in this section should be used. Both, a prosaic
description of the algorithm and a pseudo-code description are
provided.
The goal is to find the largest value, R, of a SIP Session Attempt
Rate, measured in sessions-per-second, which the DUT can process with
zero errors over a defined, extended period. This period is defined
as the amount of time needed to attempt N SIP sessions, where N is a
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parameter of test, at the attempt rate, R. An iterative process is
used to find this rate. The iterative process is divided into two
distinct phases: Candidate Identification and Steady State Testing.
During the Candidate Identification phase, the test runs until n
sessions have been attempted, at session attempt rates, r, which vary
according to the algorithm below, where n is also a parameter of test
and is a relatively large number, but an order of magnitude smaller
than N. If no errors occur during the time it takes to attempt n
sessions, we increment r according to the algorithm. If errors are
encountered during the test, we decrement r according to the
algorithm. The algorithm provides a variable, G, that allows us to
control how the accuracy, in sessions per second, that we require of
the test.
After this candidate rate has been discovered, the test enters the
Steady State phase. In the Steady State phase, N session Attempts
are made at the candidate rate. The goal is to find a rate at which
the DUT can process calls "forever" with no errors and the test
organization can choose N as large as it deems appropriate. If
errors are encountered during this steady-state phase, the candidate
rate is reduced by a defined percent, also a parameter of test, and
the steady-state phase is entered again until a final (new) steady-
state rate is achieved.
The iterative process itself is defined as follows: A starting rate
of r = 100 sessions per second is used and we place calls at that
rate until n = 5000 calls have been placed. If all n calls are
successful, the rate is increased to 150 sps and again we place calls
at that rate until n = 5000 calls have been placed. The attempt rate
is continuously ramped up until a failure is encountered before n =
5000 calls have been placed. Then an attempt rate is calculated that
is higher than the last successful attempt rate by a quantity equal
to half the difference between the rate at which failures occurred
and the last successful rate. If this new attempt rate also results
in errors, a new attempt rate is tried that is higher than the last
successful attempt rate by a quantity equal to half the difference
between the rate at which failures occurred and the last successful
rate. Continuing in this way, an attempt rate without errors is
found. The tester can specify margin of error using the parameter G,
measured in units of sessions per second.
The pseudo-code corresponding to the description above follows.
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; ---- Parameters of test, adjust as needed
n := 5000 ; local maximum; used to figure out largest
; value (number of sessions attempted)
N := 50000 ; global maximum; once largest session rate has
; been established, send this many requests before
; calling the test a success
m := {...} ; other attributes that affect testing, such
; as media streams, etc.
r := 100 ; Initial session attempt rate (in sessions/sec)
G := 5 ; granularity of results - the margin of error in
; sps
C := 0.05 ; calibration amount: How much to back down if we
; have found candidate s but cannot send at rate s
; for time T without failures
; ---- End of parameters of test
; ---- Initialization of flags, candidate values and upper bounds
f := false ; indicates a success after the upper limit
F := false ; indicates that test is done
c := 0 ; indicates that we have found an upper limit
proc find_largest_value
; Iterative process to figure out the largest value we can
; handle with no failures
do {
send_traffic(r, m, n) ; Send r request/sec with m
; characteristics until n
; requests have been sent
if (all requests succeeded) {
r' := r ; save candidate value of metric
if ( c == 0 ) {
r := r + (0.5 * r)
}
else if ((c == 1) && (r''-r')) > 2*G ) {
r := r + ( 0.5 * (r'' - r );
}
else if ((c == 1) && ((r''-r') <= 2*G ) {
f := true;
}
else if (one or more requests fail) {
c := 1 ; found upper bound for the metric
r'' := r ; save new upper bound
r := r - (0.5 * (r - r'))
}
} while (f == false)
end proc
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5. Reporting Format
5.1. Test Setup Report
SIP Transport Protocol = ___________________________
(valid values: TCP|UDP|TLS|SCTP|websockets|specify-other)
Session Attempt Rate = _____________________________
(session attempts/sec)
Total Sessions Attempted = _________________________
(total sessions to be created over duration of test)
Media Streams Per Session = _______________________
(number of streams per session)
Associated Media Protocol = _______________________
(RTP|RTSP|specify-other)
Media Packet Size = _______________________________
(bytes)
Establishment Threshold time = ____________________
(seconds)
TLS ciphersuite used
(for tests involving TLS) = ________________________
(e.g., TLS_RSA_WITH_AES_128_CBC_SHA)
IPSec profile used
(for tests involving IPSEC) = _____________________
5.2. Device Benchmarks for IS
Session Establishment Rate = ______________________
(sessions per second)
Is DUT acting as a media relay (yes/no) = _________
5.3. Device Benchmarks for NS
Registration Rate = ____________________________
(registrations per second)
Re-registration Rate = ____________________________
(registrations per second)
6. Test Cases
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6.1. Baseline Session Establishment Rate of the test bed
Objective:
To benchmark the Session Establishment Rate of the Emulated Agent
(EA) with zero failures.
Procedure:
1. Configure the DUT in the test topology shown in Figure 1.
2. Set media streams per session to 0.
3. Execute benchmarking algorithm as defined in Section 4.8 to
get the baseline session establishment rate. This rate MUST
be recorded using any pertinent parameters as shown in the
reporting format of Section 5.1.
Expected Results: This is the scenario to obtain the maximum Session
Establishment Rate of the EA and the test bed when no DUT is
present. The results of this test might be used to normalize test
results performed on different test beds or simply to better
understand the impact of the DUT on the test bed in question.
6.2. Session Establishment Rate without media
Objective:
To benchmark the Session Establishment Rate of the DUT with no
associated media and zero failures.
Procedure:
1. Configure a DUT according to the test topology shown in
Figure 1 or Figure 2.
2. Set media streams per session to 0.
3. Execute benchmarking algorithm as defined in Section 4.8 to
get the session establishment rate. This rate MUST be
recorded using any pertinent parameters as shown in the
reporting format of Section 5.1.
Expected Results: Find the Session Establishment Rate of the DUT
when the EA is not sending media streams.
6.3. Session Establishment Rate with Media not on DUT
Objective:
To benchmark the Session Establishment Rate of the DUT with zero
failures when Associated Media is included in the benchmark test
but the media is not running through the DUT.
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Procedure:
1. Configure a DUT according to the test topology shown in
Figure 1.
2. Set media streams per session to 1.
3. Execute benchmarking algorithm as defined in Section 4.8 to
get the session establishment rate with media. This rate MUST
be recorded using any pertinent parameters as shown in the
reporting format of Section 5.1.
Expected Results: Session Establishment Rate results obtained with
Associated Media with any number of media streams per SIP session
are expected to be identical to the Session Establishment Rate
results obtained without media in the case where the DUT is
running on a platform separate from the platform on which the
Media Relay.
6.4. Session Establishment Rate with Media on DUT
Objective:
To benchmark the Session Establishment Rate of the DUT with zero
failures when Associated Media is included in the benchmark test
and the media is running through the DUT.
Procedure:
1. Configure a DUT according to the test topology shown in
Figure 2.
2. Set media streams per session to 1.
3. Execute benchmarking algorithm as defined in Section 4.8 to
get the session establishment rate with media. This rate MUST
be recorded using any pertinent parameters as shown in the
reporting format of Section 5.1.
Expected Results: Session Establishment Rate results obtained with
Associated Media may be lower than those obtained without media in
the case where the DUT and the Media Relay are running on the same
platform.
6.5. Session Establishment Rate with TLS Encrypted SIP
Objective:
To benchmark the Session Establishment Rate of the DUT with zero
failures when using TLS encrypted SIP signaling.
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Procedure:
1. If the DUT is being benchmarked as a proxy or B2BUA, then
configure the DUT in the test topology shown in Figure 1 or
Figure 2.
2. Configure the tester to enable TLS over the transport being
used during benchmarking. Note the ciphersuite being used for
TLS and record it in Section 5.1.
3. Set media streams per session to 0 (media is not used in this
test).
4. Execute benchmarking algorithm as defined in Section 4.8 to
get the session establishment rate with TLS encryption.
Expected Results: Session Establishment Rate results obtained with
TLS Encrypted SIP may be lower than those obtained with plaintext
SIP.
6.6. Session Establishment Rate with IPsec Encrypted SIP
Objective:
To benchmark the Session Establishment Rate of the DUT with zero
failures when using IPsec Encrypted SIP signaling.
Procedure:
1. Configure a DUT according to the test topology shown in
Figure 1 or Figure 2.
2. Set media streams per session to 0 (media is not used in this
test).
3. Configure tester for IPSec. Note the IPSec profile being used
for and record it in Section 5.1.
4. Execute benchmarking algorithm as defined in Section 4.8 to
get the session establishment rate with encryption.
Expected Results: Session Establishment Rate results obtained with
IPSec Encrypted SIP may be lower than those obtained with
plaintext SIP.
6.7. Registration Rate
Objective:
To benchmark the maximum registration rate the DUT can handle over
an extended time period with zero failures.
Procedure:
1. Configure a DUT according to the test topology shown in
Figure 1 or Figure 2.
2. Set the registration timeout value to at least 3600 seconds.
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3. Execute benchmarking algorithm as defined in Section 4.8 to
get the maximum registration rate. This rate MUST be recorded
using any pertinent parameters as shown in the reporting
format of Section 5.1. For example, the use of TLS or IPSec
during registration must be noted in the reporting format.
Expected Results: Provides a maximum registration rate.
6.8. Re-Registration Rate
Objective:
To benchmark the re-registration rate of the DUT with zero
failures.
Procedure:
1. Configure a DUT according to the test topology shown in
Figure 1 or Figure 2.
2. First, execute test detailed in Section 6.7 to register the
endpoints with the registrar and obtain the registration rate.
3. After at least 5 minutes of Step 2, but no more than 10
minutes after Step 2 has been performed, execute Step 3 of the
test in Section 6.7. This will count as a re-registration
because the SIP address of records have not yet expired.
Expected Results: The rate should be at least equal to but not more
than the result of Section 6.7.
7. IANA Considerations
This document does not requires any IANA considerations.
8. Security Considerations
Documents of this type do not directly affect the security of
Internet or corporate networks as long as benchmarking is not
performed on devices or systems connected to production networks.
Security threats and how to counter these in SIP and the media layer
is discussed in RFC3261, RFC3550, and RFC3711 and various other
drafts. This document attempts to formalize a set of common
methodology for benchmarking performance of SIP devices in a lab
environment.
9. Acknowledgments
The authors would like to thank Keith Drage and Daryl Malas for their
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contributions to this document. Dale Worley provided an extensive
review that lead to improvements in the documents. We are grateful
to Barry Constantine for providing valuable comments during the
document's WGLC.
10. References
10.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
Network Interconnect Devices", RFC 2544, March 1999.
[I-D.sip-bench-term]
Davids, C., Gurbani, V., and S. Poretsky, "SIP Performance
Benchmarking Terminology",
draft-ietf-bmwg-sip-bench-term-04 (work in progress),
March 2012.
10.2. Informative References
[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M., and E.
Schooler, "SIP: Session Initiation Protocol", RFC 3261,
June 2002.
Authors' Addresses
Carol Davids
Illinois Institute of Technology
201 East Loop Road
Wheaton, IL 60187
USA
Phone: +1 630 682 6024
Email: davids@iit.edu
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Vijay K. Gurbani
Bell Laboratories, Alcatel-Lucent
1960 Lucent Lane
Rm 9C-533
Naperville, IL 60566
USA
Phone: +1 630 224 0216
Email: vkg@bell-labs.com
Scott Poretsky
Allot Communications
300 TradeCenter, Suite 4680
Woburn, MA 08101
USA
Phone: +1 508 309 2179
Email: sporetsky@allot.com
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