draft-ietf-bmwg-b2b-frame-02.txt   draft-ietf-bmwg-b2b-frame-03.txt 
Network Working Group A. Morton Network Working Group A. Morton
Internet-Draft AT&T Labs Internet-Draft AT&T Labs
Updates: 2544 (if approved) May 19, 2020 Updates: 2544 (if approved) November 16, 2020
Intended status: Informational Intended status: Informational
Expires: November 20, 2020 Expires: May 20, 2021
Updates for the Back-to-back Frame Benchmark in RFC 2544 Updates for the Back-to-back Frame Benchmark in RFC 2544
draft-ietf-bmwg-b2b-frame-02 draft-ietf-bmwg-b2b-frame-03
Abstract Abstract
Fundamental Benchmarking Methodologies for Network Interconnect Fundamental Benchmarking Methodologies for Network Interconnect
Devices of interest to the IETF are defined in RFC 2544. This memo Devices of interest to the IETF are defined in RFC 2544. This memo
updates the procedures of the test to measure the Back-to-back frames updates the procedures of the test to measure the Back-to-back frames
Benchmark of RFC 2544, based on further experience. Benchmark of RFC 2544, based on further experience.
This memo updates Section 26.4 of RFC 2544. This memo updates Section 26.4 of RFC 2544.
skipping to change at page 1, line 44 skipping to change at page 1, line 44
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 20, 2020. This Internet-Draft will expire on May 20, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
skipping to change at page 2, line 28 skipping to change at page 2, line 28
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Scope and Goals . . . . . . . . . . . . . . . . . . . . . . . 3 2. Scope and Goals . . . . . . . . . . . . . . . . . . . . . . . 3
3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . 6
5. Back-to-back Frames . . . . . . . . . . . . . . . . . . . . . 7 5. Back-to-back Frames . . . . . . . . . . . . . . . . . . . . . 7
5.1. Preparing the list of Frame sizes . . . . . . . . . . . . 7 5.1. Preparing the list of Frame sizes . . . . . . . . . . . . 7
5.2. Test for a Single Frame Size . . . . . . . . . . . . . . 7 5.2. Test for a Single Frame Size . . . . . . . . . . . . . . 8
5.3. Test Repetition and Benchmark . . . . . . . . . . . . . . 9 5.3. Test Repetition and Benchmark . . . . . . . . . . . . . . 9
5.4. Benchmark Calculations . . . . . . . . . . . . . . . . . 9 5.4. Benchmark Calculations . . . . . . . . . . . . . . . . . 9
6. Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6. Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Security Considerations . . . . . . . . . . . . . . . . . . . 11 7. Security Considerations . . . . . . . . . . . . . . . . . . . 11
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
10.1. Normative References . . . . . . . . . . . . . . . . . . 12 10.1. Normative References . . . . . . . . . . . . . . . . . . 12
10.2. Informative References . . . . . . . . . . . . . . . . . 13 10.2. Informative References . . . . . . . . . . . . . . . . . 13
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 14
1. Introduction 1. Introduction
The IETF's fundamental Benchmarking Methodologies are defined The IETF's fundamental Benchmarking Methodologies are defined in
in[RFC2544], supported by the terms and definitions in [RFC1242], and [RFC2544], supported by the terms and definitions in [RFC1242], and
[RFC2544] actually obsoletes an earlier specification, [RFC1944]. [RFC2544] actually obsoletes an earlier specification, [RFC1944].
Over time, the benchmarking community has updated [RFC2544] several Over time, the benchmarking community has updated [RFC2544] several
times, including the Device Reset Benchmark [RFC6201], and the times, including the Device Reset Benchmark [RFC6201], and the
important Applicability Statement [RFC6815] concerning use outside important Applicability Statement [RFC6815] concerning use outside
the Isolated Test Environment (ITE) required for accurate the Isolated Test Environment (ITE) required for accurate
benchmarking. Other specifications implicitly update [RFC2544], such benchmarking. Other specifications implicitly update [RFC2544], such
as the IPv6 Benchmarking Methodologies in [RFC5180]. as the IPv6 Benchmarking Methodologies in [RFC5180].
Recent testing experience with the Back-to-back Frame test and Recent testing experience with the Back-to-back Frame test and
Benchmark in Section 26.4 of [RFC2544] indicates that an update is Benchmark in Section 26.4 of [RFC2544] indicates that an update is
warranted [OPNFV-2017] [VSPERF-b2b]. In particular, analysis of the warranted [OPNFV-2017] [VSPERF-b2b]. In particular, analysis of the
results indicates that buffers size matters when compensating for results indicates that buffer size matters when compensating for
disruptions in the software packet processor, and this finding interruptions of software packet processing, and this finding
increases the importance of the Back-to-back frame characterization increases the importance of the Back-to-back frame characterization
described here. This memo describes additional rationale and described here. This memo describes additional rationale and
provides the updated method. provides the updated method.
[RFC2544] provides its own Requirements Language consistent with [RFC2544] (which Obsoletes [RFC1944]) provides its own Requirements
[RFC2119], since [RFC1944] predates [RFC2119]. Thus, the Language consistent with [RFC2119], since [RFC1944] pre-dates
requirements presented in this memo are expressed in [RFC2119] terms, [RFC2119] and all three memos share common authorship.
Today,[RFC8174] clarifies the usage of Requirements Language, so the
requirements presented in this memo are expressed in [RFC8174] terms,
and intended for those performing/reporting laboratory tests to and intended for those performing/reporting laboratory tests to
improve clarity and repeatability, and for those designing devices improve clarity and repeatability, and for those designing devices
that facilitate these tests. that facilitate these tests.
2. Scope and Goals 2. Scope and Goals
The scope of this memo is to define an updated method to The scope of this memo is to define an updated method to
unambiguously perform tests, measure the benchmark(s), and report the unambiguously perform tests, measure the benchmark(s), and report the
results for Back-to-back Frames (presently described Section 26.4 of results for Back-to-back Frames (presently described Section 26.4 of
[RFC2544]). [RFC2544]).
The goal is to provide more efficient test procedures where possible, The goal is to provide more efficient test procedures where possible,
and to expand reporting with additional interpretation of the and to expand reporting with additional interpretation of the
results. The tests described in this memo address the cases where results. The tests described in this memo address the cases in which
the maximum frame rate of a single ingress port cannot be transferred the maximum frame rate of a single ingress port cannot be transferred
to an egress port loss-free (for some frame sizes of interest). loss-free to an egress port (for some frame sizes of interest).
[RFC2544] Benchmarks rely on test conditions with constant frame [RFC2544] Benchmarks rely on test conditions with constant frame
sizes, with the goal of understanding what network device capability sizes, with the goal of understanding what network device capability
has been tested. Tests with the smallest size stress the header has been tested. Tests with the smallest size stress the header
processing capacity, and tests with the largest size stress the processing capacity, and tests with the largest size stress the
overall bit processing capacity. Tests with sizes in-between may overall bit processing capacity. Tests with sizes in-between may
determine the transition between these two capacities. However, determine the transition between these two capacities. However,
conditions simultaneously sending multiple frame sizes, such as those conditions simultaneously sending multiple frame sizes, such as those
described in [RFC6985], MUST NOT be used in Back-to-back Frame described in [RFC6985], MUST NOT be used in Back-to-back Frame
testing. testing.
Section 3 of [RFC8239] describes buffer size testing for physical Section 3 of [RFC8239] describes buffer size testing for physical
networking devices in a Data Center. The [RFC8239] methods measure networking devices in a Data Center. The [RFC8239] methods measure
buffer latency directly with traffic on multiple ingress ports that buffer latency directly with traffic on multiple ingress ports that
overload an egress port on the Device Under Test (DUT), and are not overload an egress port on the Device Under Test (DUT) and are not
subject to the revised calculations presented in this memo. subject to the revised calculations presented in this memo.
Likewise, the methods of [RFC8239] SHOULD be used for test cases Likewise, the methods of [RFC8239] SHOULD be used for test cases
where the egress port buffer is the known point of overload. where the egress port buffer is the known point of overload.
3. Motivation 3. Motivation
Section 3.1 of [RFC1242] describes the rationale for the Back-to-back Section 3.1 of [RFC1242] describes the rationale for the Back-to-back
Frames Benchmark. To summarize, there are several reasons that Frames Benchmark. To summarize, there are several reasons that
devices on a network produce bursts of frames at the minimum allowed devices on a network produce bursts of frames at the minimum allowed
spacing, and it is therefore worthwhile to understand the Device spacing; and it is, therefore, worthwhile to understand the Device
Under Test (DUT) limit on the length of such bursts in practice. Under Test (DUT) limit on the length of such bursts in practice.
Also, [RFC1242] states: Also, [RFC1242] states:
"Tests of this parameter are intended to determine the extent "Tests of this parameter are intended to determine the extent
of data buffering in the device." of data buffering in the device."
After this test was defined, there have been occasional discussions After this test was defined, there have been occasional discussions
of the stability and repeatability of the results, both over time and of the stability and repeatability of the results, both over time and
across labs. Fortunately, the Open Platform for Network Function across labs. Fortunately, the Open Platform for Network Function
Virtualization (OPNFV) VSPERF project's Continuous Integration (CI) Virtualization (OPNFV) VSPERF project's Continuous Integration (CI)
testing routinely repeats Back-to-back Frame tests to verify that [VSPERF-CI] testing routinely repeats Back-to-back Frame tests to
test functionality has been maintained through development of the verify that test functionality has been maintained through
test control programs. These tests were used as a basis to evaluate development of the test control programs. These tests were used as a
stability and repeatability, even across lab set-ups when the test basis to evaluate stability and repeatability, even across lab set-
platform was migrated to new DUT hardware at the end of 2016. ups when the test platform was migrated to new DUT hardware at the
end of 2016.
When the VSPERF CI results were examined [VSPERF-b2b], several When the VSPERF CI results were examined [VSPERF-b2b], several
aspects of the results were considered notable: aspects of the results were considered notable:
1. Back-to-back Frame Benchmark was very consistent for some fixed 1. Back-to-back Frame Benchmark was very consistent for some fixed
frame sizes, and somewhat variable for others. frame sizes, and somewhat variable for other frame sizes.
2. The number of Back-to-back Frames with zero loss reported for 2. The number of Back-to-back Frames with zero loss reported for
large frame sizes was unexpectedly long (translating to 30 large frame sizes was unexpectedly long (translating to 30
seconds of buffer time), and no explanation or measurement limit seconds of buffer time), and no explanation or measurement limit
condition was indicated. It's important that the buffering time condition was indicated. It was important that the buffering
was used in this analysis. The referenced testing [VSPERF-b2b] time calculations were part of the referenced testing and
and calculations produced buffer extents of 30 seconds for some analysis[VSPERF-b2b], because the calculated buffer times of 30
frame sizes, and clearly wrong in practice. On the other hand, a seconds for some frame sizes were clearly wrong or highly
result expressed only as a large number of Back-to-back Frames suspect. On the other hand, a result expressed only as a large
does not permit such an easy comparison with reality. number of Back-to-back Frames does not permit such an easy
comparison with reality.
3. Calculation of the extent of buffer time in the DUT helped to 3. Calculation of the extent of buffer time in the DUT helped to
explain the results observed with all frame sizes (for example, explain the results observed with all frame sizes (for example,
some frame sizes cannot exceed the frame header processing rate tests with some frame sizes cannot exceed the frame header
of the DUT and therefore no buffering occurs, therefore the processing rate of the DUT and thus no buffering occurs;
results depended on the test equipment and not the DUT). therefore, the results depended on the test equipment and not the
DUT).
4. It was found that the actual extent of buffer time in the DUT 4. It was found that a better estimate of the DUT buffer time could
could be estimated using results to measure the longest burst in be calculated using measurements of both the longest burst in
frames without loss and results from the Throughput tests frames without loss and results from the Throughput tests
conducted according to Section 26.1 of [RFC2544]. It is apparent conducted according to Section 26.1 of [RFC2544]. It is apparent
that the DUT's frame processing rate empties the buffer during a that the DUT's frame processing rate empties the buffer during a
trial and tends to increase the "implied" buffer size estimate trial and tends to increase the "implied" buffer size estimate
(measured according to Section 26.4 of [RFC2544] because many (measured according to Section 26.4 of [RFC2544] because many
frames have left the buffer when the burst of frames ends). A frames have departed the buffer when the burst of frames ends).
calculation using the Throughput measurement can reveal a A calculation using the Throughput measurement can reveal a
"corrected" buffer size estimate. "corrected" buffer size estimate.
Further, if the Throughput tests of Section 26.1 of [RFC2544] are Further, if the Throughput tests of Section 26.1 of [RFC2544] are
conducted as a prerequisite test, the number of frame sizes required conducted as a prerequisite test, the number of frame sizes required
for Back-to-back Frame Benchmarking can be reduced to one or more of for Back-to-back Frame Benchmarking can be reduced to one or more of
the small frame sizes, or the results for large frame sizes can be the small frame sizes, or the results for large frame sizes can be
noted as invalid in the results if tested anyway (these are the noted as invalid in the results if tested anyway (these are the
larger frame sizes for which the back-to-back frame rate cannot larger frame sizes for which the back-to-back frame rate cannot
exceed the frame header processing rate of the DUT and little or no exceed the frame header processing rate of the DUT and little or no
buffering occurs). buffering occurs).
[VSPERF-b2b] provides the details of the calculation to estimate the The material below provides the details of the calculation to
actual buffer storage available in the DUT, using results from the estimate the actual buffer storage available in the DUT, using
Throughput tests for each frame size, and the maximum theoretical results from the Throughput tests for each frame size, and the
frame rate for the DUT links (which constrain the minimum frame maximum theoretical frame rate for the DUT links (which constrain the
spacing). minimum frame spacing).
In reality, there are many buffers and packet header processing steps In reality, there are many buffers and packet header processing steps
in a typical DUT. The simplified model used in these calculations in a typical DUT. The simplified model used in these calculations
for the DUT includes a packet header processing function with limited for the DUT includes a packet header processing function with limited
rate of operation, as shown below: rate of operation, as shown below:
|------------ DUT --------| |------------ DUT --------|
Generator -> Ingress -> Buffer -> HeaderProc -> Egress -> Receiver Generator -> Ingress -> Buffer -> HeaderProc -> Egress -> Receiver
So, in the back2back frame testing: So, in the back2back frame testing:
skipping to change at page 5, line 48 skipping to change at page 6, line 5
2. The packet header processing function (HeaderProc) operates at 2. The packet header processing function (HeaderProc) operates at
the "Measured Throughput" (Section 26.1 of [RFC2544]), removing the "Measured Throughput" (Section 26.1 of [RFC2544]), removing
frames from the buffer (this is the best approximation we have). frames from the buffer (this is the best approximation we have).
3. Frames that have been processed are clearly not in the buffer, so 3. Frames that have been processed are clearly not in the buffer, so
the Corrected DUT buffer time equation (Section 5.4) estimates the Corrected DUT buffer time equation (Section 5.4) estimates
and removes the frames that the DUT forwarded on Egress during and removes the frames that the DUT forwarded on Egress during
the burst. We define buffer time as the number of Frames the burst. We define buffer time as the number of Frames
occupying the buffer divided by the Maximum Theoretical Frame occupying the buffer divided by the Maximum Theoretical Frame
Rate (on egress) for the Frame size under test. Rate (on ingress) for the Frame size under test.
4. A helpful concept is the buffer filling rate, which is the 4. A helpful concept is the buffer filling rate, which is the
difference between the Max Theoretical Frame Rate (ingress) and difference between the Max Theoretical Frame Rate (ingress) and
the Measured Throughput (HeaderProc on egress). If the actual the Measured Throughput (HeaderProc on egress). If the actual
buffer size in frames was known, the time to fill the buffer buffer size in frames was known, the time to fill the buffer
during a measurement can be calculated using the filling rate as during a measurement can be calculated using the filling rate as
a check on measurements. However, the Buffer in the model a check on measurements. However, the Buffer in the model
represents many buffers of different sizes in the DUT data path. represents many buffers of different sizes in the DUT data path.
Knowledge of approximate buffer storage size (in time or bytes) may Knowledge of approximate buffer storage size (in time or bytes) may
be useful to estimate whether frame losses will occur if DUT be useful to estimate whether frame losses will occur if DUT
forwarding is temporarily suspended in a production deployment, due forwarding is temporarily suspended in a production deployment, due
to an unexpected interruption of frame processing (an interruption of to an unexpected interruption of frame processing (an interruption of
duration greater than the estimated buffer would certainly cause lost duration greater than the estimated buffer would certainly cause lost
frames). In Section 5, the calculations for the correct buffer time frames). In Section 5, the calculations for the correct buffer time
for the combination of offered load at Max Theoretical Frame Rate and use the combination of offered load at Max Theoretical Frame Rate and
header processing speed at 100% of Measured Throughput. Other header processing speed at 100% of Measured Throughput. Other
combinations are possible, such as changing the percent of measured combinations are possible, such as changing the percent of measured
Throughput to account for other processes reducing the header Throughput to account for other processes reducing the header
processing rate. processing rate.
The presentation of OPNFV VSPERF evaluation and development of The presentation of OPNFV VSPERF evaluation and development of
enhanced search alogorithms [VSPERF-BSLV] was discussed at IETF-102. enhanced search algorithms [VSPERF-BSLV] was discussed at IETF-102.
The enhancements are intended to compensate for transient inerrrupts The enhancements are intended to compensate for transient interrupts
that may cause loss at near-Throughput levels of offered load. that may cause loss at near-Throughput levels of offered load.
Subsequent analysis of the results indicates that buffers within the Subsequent analysis of the results indicates that buffers within the
DUT can compensate for some interrupts, and this finding increases DUT can compensate for some interrupts, and this finding increases
the importance of the Back-to-back frame characterization described the importance of the Back-to-back frame characterization described
here. here.
4. Prerequisites 4. Prerequisites
The Test Setup MUST be consistent with Figure 1 of [RFC2544], or The Test Setup MUST be consistent with Figure 1 of [RFC2544], or
Figure 2 when the tester's sender and receiver are different devices. Figure 2 when the tester's sender and receiver are different devices.
skipping to change at page 7, line 7 skipping to change at page 7, line 9
The test results for the Throughput Benchmark conducted according to The test results for the Throughput Benchmark conducted according to
Section 26.1 of [RFC2544] for all [RFC2544]-RECOMMENDED frame sizes Section 26.1 of [RFC2544] for all [RFC2544]-RECOMMENDED frame sizes
MUST be available to reduce the tested frame size list, or to note MUST be available to reduce the tested frame size list, or to note
invalid results for individual frame sizes (because the burst length invalid results for individual frame sizes (because the burst length
may be essentially infinite for large frame sizes). may be essentially infinite for large frame sizes).
Note that: Note that:
o the Throughput and the Back-to-back Frame measurement o the Throughput and the Back-to-back Frame measurement
configuration traffic characteristics (unidirectional or bi- configuration traffic characteristics (unidirectional or bi-
directional) MUST match. directional, and number of flows generated) MUST match.
o the Throughput measurement MUST be under zero-loss conditions, o the Throughput measurement MUST be under zero-loss conditions,
according to Section 26.1 of [RFC2544]. according to Section 26.1 of [RFC2544].
The Back-to-back Benchmark described in Section 3.1 of [RFC1242] MUST The Back-to-back Benchmark described in Section 3.1 of [RFC1242] MUST
be measured directly by the tester, where buffer size is inferred be measured directly by the tester, where buffer size is inferred
from Back-to-back Frame bursts and associated packet loss from Back-to-back Frame bursts and associated packet loss
measurements. Therefore, sources of packet loss that are un-related measurements. Therefore, sources of packet loss that are unrelated
to consistent evaluation of buffer size SHOULD be identified and to consistent evaluation of buffer size SHOULD be identified and
removed or mitigated. Example sources include: removed or mitigated. Example sources include:
o On-path active components that are external to the DUT o On-path active components that are external to the DUT
o Operating system environment interrupting DUT operation o Operating system environment interrupting DUT operation
o Shared resource contention between the DUT and other off-path o Shared resource contention between the DUT and other off-path
component(s) impacting DUT's behaviour, sometimes called the component(s) impacting DUT's behaviour, sometimes called the
"noisy neighbour" problem with virtualized network functions. "noisy neighbour" problem with virtualized network functions.
skipping to change at page 8, line 25 skipping to change at page 8, line 31
for the next trial (the burst length is typically reduced, but see for the next trial (the burst length is typically reduced, but see
below). below).
Classic search algorithms have been adapted for use in benchmarking, Classic search algorithms have been adapted for use in benchmarking,
where the search requires discovery of a pair of outcomes, one with where the search requires discovery of a pair of outcomes, one with
no loss and another with loss, at load conditions within the no loss and another with loss, at load conditions within the
acceptable tolerance or accuracy. Conditions encountered when acceptable tolerance or accuracy. Conditions encountered when
benchmarking the Infrastructure for Network Function Virtualization benchmarking the Infrastructure for Network Function Virtualization
require algorithm enhancement. Fortunately, the adaptation of Binary require algorithm enhancement. Fortunately, the adaptation of Binary
Search, and an enhanced Binary Search with Loss Verification have Search, and an enhanced Binary Search with Loss Verification have
been specified in clause 12.3 of [TST009]. These alogorithms can been specified in clause 12.3 of [TST009]. These algorithms can
easily be used for Back-to-back Frame benchmarking by replacing the easily be used for Back-to-back Frame benchmarking by replacing the
Offered Load level with burst length in frames. [TST009] Annex B Offered Load level with burst length in frames. [TST009] Annex B
describes the theory behind the enhanced Binary Search with Loss describes the theory behind the enhanced Binary Search with Loss
Verification algorithm. Verification algorithm.
There is also promising work-in-progress that may prove useful in for There is also promising work-in-progress that may prove useful in
Back-to-back Frame benchmarking. Back-to-back Frame benchmarking.
[I-D.vpolak-mkonstan-bmwg-mlrsearch] and [I-D.vpolak-bmwg-plrsearch] [I-D.vpolak-mkonstan-bmwg-mlrsearch] and [I-D.vpolak-bmwg-plrsearch]
are two such examples. are two such examples.
Either the [TST009] Binary Search or Binary Search with Loss Either the [TST009] Binary Search or Binary Search with Loss
Verification algorithms MUST be used, and input parameters to the Verification algorithms MUST be used, and input parameters to the
algorithm(s) MUST be reported. algorithm(s) MUST be reported.
The tester usually imposes a (configurable) minimum step size for The tester usually imposes a (configurable) minimum step size for
burst length, and the step size MUST be reported with the results (as burst length, and the step size MUST be reported with the results (as
skipping to change at page 10, line 16 skipping to change at page 10, line 18
/ \ / \
Implied DUT |Implied DUT Measured Throughput | Implied DUT |Implied DUT Measured Throughput |
= Buffer Time - |Buffer Time * -------------------------- | = Buffer Time - |Buffer Time * -------------------------- |
| Max Theoretical Frame Rate | | Max Theoretical Frame Rate |
\ / \ /
where: where:
1. The "Measured Throughput" is the [RFC2544] Throughput Benchmark 1. The "Measured Throughput" is the [RFC2544] Throughput Benchmark
for the frame size tested, as augmented by methods including the for the frame size tested, as augmented by methods including the
Binary Search with Loss Verification aglorithm in [TST009] where Binary Search with Loss Verification algorithm in [TST009] where
applicable, and MUST be expressed in Frames per second in this applicable, and MUST be expressed in Frames per second in this
equation. equation.
2. The "Max Theoretical Frame Rate" is a calculated value for the 2. The "Max Theoretical Frame Rate" is a calculated value for the
interface speed and link layer technology used, and MUST be interface speed and link layer technology used, and MUST be
expressed in Frames per second in this equation. expressed in Frames per second in this equation.
The term on the far right in the formula for Corrected DUT Buffer The term on the far right in the formula for Corrected DUT Buffer
Time accounts for all the frames in the Burst that were transmitted Time accounts for all the frames in the Burst that were transmitted
by the DUT *while the Burst of frames were sent in*. So, these frames by the DUT *while the Burst of frames were sent in*. So, these frames
skipping to change at page 12, line 17 skipping to change at page 12, line 17
This memo makes no requests of IANA. This memo makes no requests of IANA.
9. Acknowledgements 9. Acknowledgements
Thanks to Trevor Cooper, Sridhar Rao, and Martin Klozik of the VSPERF Thanks to Trevor Cooper, Sridhar Rao, and Martin Klozik of the VSPERF
project for many contributions to the testing [VSPERF-b2b]. Yoshiaki project for many contributions to the testing [VSPERF-b2b]. Yoshiaki
Itou has also investigated the topic, and made useful suggestions. Itou has also investigated the topic, and made useful suggestions.
Maciek Konstantyowicz and Vratko Polak also provided many comments Maciek Konstantyowicz and Vratko Polak also provided many comments
and suggestions based on extensive integration testing and resulting and suggestions based on extensive integration testing and resulting
search algorithm proposals - the most up-to-date feedback possible. search algorithm proposals - the most up-to-date feedback possible.
Tim Carlin also provided comments and support for the draft. Tim Carlin also provided comments and support for the draft. Warren
Kumari's review improved readability in several key passages.
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC1242] Bradner, S., "Benchmarking Terminology for Network [RFC1242] Bradner, S., "Benchmarking Terminology for Network
Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242, Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242,
July 1991, <https://www.rfc-editor.org/info/rfc1242>. July 1991, <https://www.rfc-editor.org/info/rfc1242>.
[RFC1944] Bradner, S. and J. McQuaid, "Benchmarking Methodology for [RFC1944] Bradner, S. and J. McQuaid, "Benchmarking Methodology for
skipping to change at page 14, line 19 skipping to change at page 14, line 19
AppendixB:Back2BackTestingTimeSeries(fromCI)>. AppendixB:Back2BackTestingTimeSeries(fromCI)>.
[VSPERF-BSLV] [VSPERF-BSLV]
Morton, A. and S. Rao, "Evolution of Repeatability in Morton, A. and S. Rao, "Evolution of Repeatability in
Benchmarking: Fraser Plugfest (Summary for IETF BMWG)", Benchmarking: Fraser Plugfest (Summary for IETF BMWG)",
July 2018, July 2018,
<https://datatracker.ietf.org/meeting/102/materials/ <https://datatracker.ietf.org/meeting/102/materials/
slides-102-bmwg-evolution-of-repeatability-in- slides-102-bmwg-evolution-of-repeatability-in-
benchmarking-fraser-plugfest-summary-for-ietf-bmwg-00>. benchmarking-fraser-plugfest-summary-for-ietf-bmwg-00>.
[VSPERF-CI]
Tahhan, M., "OPNFV VSPERF CI", June 2019,
<https://wiki.opnfv.org/display/vsperf/VSPERF+CI>.
Author's Address Author's Address
Al Morton Al Morton
AT&T Labs AT&T Labs
200 Laurel Avenue South 200 Laurel Avenue South
Middletown,, NJ 07748 Middletown,, NJ 07748
USA USA
Phone: +1 732 420 1571 Phone: +1 732 420 1571
Fax: +1 732 368 1192 Fax: +1 732 368 1192
 End of changes. 29 change blocks. 
50 lines changed or deleted 60 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/