From 4bfd864f10b68b71482b35c818559068ef8d5797 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Wed, 27 Nov 2024 20:54:24 +0100 Subject: doc: Add RFC documents --- doc/rfc/rfc9004.txt | 688 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 688 insertions(+) create mode 100644 doc/rfc/rfc9004.txt (limited to 'doc/rfc/rfc9004.txt') diff --git a/doc/rfc/rfc9004.txt b/doc/rfc/rfc9004.txt new file mode 100644 index 0000000..f034096 --- /dev/null +++ b/doc/rfc/rfc9004.txt @@ -0,0 +1,688 @@ + + + + +Internet Engineering Task Force (IETF) A. Morton +Request for Comments: 9004 AT&T Labs +Updates: 2544 May 2021 +Category: Informational +ISSN: 2070-1721 + + + Updates for the Back-to-Back Frame Benchmark in RFC 2544 + +Abstract + + Fundamental benchmarking methodologies for network interconnect + 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 + benchmark of RFC 2544, based on further experience. + + This memo updates Section 26.4 of RFC 2544. + +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 candidates 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/rfc9004. + +Copyright Notice + + Copyright (c) 2021 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 + 2. Requirements Language + 3. Scope and Goals + 4. Motivation + 5. Prerequisites + 6. Back-to-Back Frames + 6.1. Preparing the List of Frame Sizes + 6.2. Test for a Single Frame Size + 6.3. Test Repetition and Benchmark + 6.4. Benchmark Calculations + 7. Reporting + 8. Security Considerations + 9. IANA Considerations + 10. References + 10.1. Normative References + 10.2. Informative References + Acknowledgments + Author's Address + +1. Introduction + + The IETF's fundamental benchmarking methodologies are defined in + [RFC2544], supported by the terms and definitions in [RFC1242]. + [RFC2544] actually obsoletes an earlier specification, [RFC1944]. + Over time, the benchmarking community has updated [RFC2544] several + times, including the Device Reset benchmark [RFC6201] and the + important Applicability Statement [RFC6815] concerning use outside + the Isolated Test Environment (ITE) required for accurate + benchmarking. Other specifications implicitly update [RFC2544], such + as the IPv6 benchmarking methodologies in [RFC5180]. + + Recent testing experience with the Back-to-Back Frame test and + benchmark in Section 26.4 of [RFC2544] indicates that an update is + warranted [OPNFV-2017] [VSPERF-b2b]. In particular, analysis of the + results indicates that buffer size matters when compensating for + interruptions of software-packet processing, and this finding + increases the importance of the Back-to-Back Frame characterization + described here. This memo provides additional rationale and the + updated method. + + [RFC2544] provides its own requirements language consistent with + [RFC2119], since [RFC1944] (which it obsoletes) predates [RFC2119]. + All three memos share common authorship. Today, [RFC8174] clarifies + the usage of requirements language, so the requirements language + presented in this memo are expressed in accordance with [RFC8174]. + They are intended for those performing/reporting laboratory tests to + improve clarity and repeatability, and for those designing devices + that facilitate these tests. + +2. Requirements Language + + 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. + +3. Scope and Goals + + The scope of this memo is to define an updated method to + unambiguously perform tests, measure the benchmark(s), and report the + results for Back-to-Back Frames (as described in Section 26.4 of + [RFC2544]). + + The goal is to provide more efficient test procedures where possible + and expand reporting with additional interpretation of the results. + The tests described in this memo address the cases in which the + maximum frame rate of a single ingress port cannot be transferred to + an egress port without loss (for some frame sizes of interest). + + Benchmarks as described in [RFC2544] rely on test conditions with + constant frame sizes, with the goal of understanding what network- + device capability has been tested. Tests with the smallest size + stress the header-processing capacity, and tests with the largest + size stress the overall bit-processing capacity. Tests with sizes in + between may determine the transition between these two capacities. + However, conditions simultaneously sending a mixture of Internet + (IMIX) frame sizes, such as those described in [RFC6985], MUST NOT be + used in Back-to-Back Frame testing. + + Section 3 of [RFC8239] describes buffer-size testing for physical + networking devices in a data center. Those methods measure buffer + latency directly with traffic on multiple ingress ports that overload + an egress port on the Device Under Test (DUT) and are not subject to + the revised calculations presented in this memo. Likewise, the + methods of [RFC8239] SHOULD be used for test cases where the egress- + port buffer is the known point of overload. + +4. Motivation + + Section 3.1 of [RFC1242] describes the rationale for the Back-to-Back + Frames benchmark. To summarize, there are several reasons that + devices on a network produce bursts of frames at the minimum allowed + spacing; and it is, therefore, worthwhile to understand the DUT limit + on the length of such bursts in practice. The same document also + states: + + | Tests of this parameter are intended to determine the extent of + | data buffering in the device. + + Since this test was defined, there have been occasional discussions + of the stability and repeatability of the results, both over time and + across labs. Fortunately, the Open Platform for Network Function + Virtualization (OPNFV) project on Virtual Switch Performance (VSPERF) + Continuous Integration (CI) [VSPERF-CI] testing routinely repeats + Back-to-Back Frame tests to verify that test functionality has been + maintained through development of the test-control programs. These + tests were used as a basis to evaluate stability and repeatability, + even across lab setups 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 + aspects of the results were considered notable: + + 1. Back-to-Back Frame benchmark was very consistent for some fixed + frame sizes, and somewhat variable for other frame sizes. + + 2. The number of Back-to-Back Frames with zero loss reported for + large frame sizes was unexpectedly long (translating to 30 + seconds of buffer time), and no explanation or measurement limit + condition was indicated. It was important that the buffering + time calculations were part of the referenced testing and + analysis [VSPERF-b2b], because the calculated buffer time of 30 + seconds for some frame sizes was clearly wrong or highly suspect. + On the other hand, a result expressed only as a large 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 + explain the results observed with all frame sizes. For example, + tests with some frame sizes cannot exceed the frame-header- + processing rate of the DUT, thus, no buffering occurs. + Therefore, the results depended on the test equipment and not the + DUT. + + 4. It was found that a better estimate of the DUT buffer time could + be calculated using measurements of both the longest burst in + frames without loss and results from the Throughput tests + conducted according to Section 26.1 of [RFC2544]. It is apparent + that the DUT's frame-processing rate empties the buffer during a + trial and tends to increase the "implied" buffer-size estimate + (measured according to Section 26.4 of [RFC2544] because many + frames have departed the buffer when the burst of frames ends). + A calculation using the Throughput measurement can reveal a + "corrected" buffer-size estimate. + + Further, if the Throughput tests of Section 26.1 of [RFC2544] are + conducted as a prerequisite, the number of frame sizes required 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 noted + as invalid in the results if tested anyway. These are the 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 buffering + occurs. + + The material below provides the details of the calculation to + estimate the actual buffer storage available in the DUT, using + results from the Throughput tests for each frame size and the Max + Theoretical Frame Rate for the DUT links (which constrain the minimum + frame spacing). + + In reality, there are many buffers and packet-header-processing steps + in a typical DUT. The simplified model used in these calculations + for the DUT includes a packet-header-processing function with limited + rate of operation, as shown in Figure 1. + + |------------ DUT --------| + Generator -> Ingress -> Buffer -> HeaderProc -> Egress -> Receiver + + Figure 1: Simplified Model for DUT Testing + + So, in the Back-to-Back Frame testing: + + 1. The ingress burst arrives at Max Theoretical Frame Rate, and + initially the frames are buffered. + + 2. The packet-header-processing function (HeaderProc) operates at + the "Measured Throughput" (Section 26.1 of [RFC2544]), removing + frames from the buffer (this is the best approximation we have, + another acceptable approximation is the received frame rate + during Back-to-back Frame testing, if Measured Throughput is not + available). + + 3. Frames that have been processed are clearly not in the buffer, so + the Corrected DUT Buffer Time equation (Section 6.4) estimates + and removes the frames that the DUT forwarded on egress during + the burst. We define buffer time as the number of frames + occupying the buffer divided by the Max Theoretical Frame Rate + (on ingress) for the frame size under test. + + 4. A helpful concept is the buffer-filling rate, which is the + difference between the Max Theoretical Frame Rate (ingress) and + the Measured Throughput (HeaderProc on egress). If the actual + buffer size in frames is known, the time to fill the buffer + during a measurement can be calculated using the filling rate, as + a check on measurements. However, the buffer in the model + represents many buffers of different sizes in the DUT data path. + + Knowledge of approximate buffer storage size (in time or bytes) may + be useful in estimating whether frame losses will occur if DUT + forwarding is temporarily suspended in a production deployment due to + an unexpected interruption of frame processing (an interruption of + duration greater than the estimated buffer would certainly cause lost + frames). In Section 6, the calculations for the correct buffer time + use the combination of offered load at Max Theoretical Frame Rate and + header-processing speed at 100% of Measured Throughput. Other + combinations are possible, such as changing the percent of Measured + Throughput to account for other processes reducing the header + processing rate. + + The presentation of OPNFV VSPERF evaluation and development of + enhanced search algorithms [VSPERF-BSLV] was given and discussed at + IETF 102. The enhancements are intended to compensate for transient + processor interrupts that may cause loss at near-Throughput levels of + offered load. Subsequent analysis of the results indicates that + buffers within the DUT can compensate for some interrupts, and this + finding increases the importance of the Back-to-Back Frame + characterization described here. + +5. Prerequisites + + The test setup MUST be consistent with Figure 1 of [RFC2544], or + Figure 2 of that document when the tester's sender and receiver are + different devices. Other mandatory testing aspects described in + [RFC2544] MUST be included, unless explicitly modified in the next + section. + + The ingress and egress link speeds and link-layer protocols MUST be + specified and used to compute the Max Theoretical Frame Rate when + respecting the minimum interframe gap. + + The test results for the Throughput benchmark conducted according to + Section 26.1 of [RFC2544] for all frame sizes RECOMMENDED by + [RFC2544] MUST be available to reduce the tested-frame-size list or + to note invalid results for individual frame sizes (because the burst + length may be essentially infinite for large frame sizes). + + Note that: + + * the Throughput and the Back-to-Back Frame measurement- + configuration traffic characteristics (unidirectional or + bidirectional, and number of flows generated) MUST match. + + * the Throughput measurement MUST be taken under zero-loss + conditions, according to Section 26.1 of [RFC2544]. + + The Back-to-Back Benchmark described in Section 3.1 of [RFC1242] MUST + be measured directly by the tester, where buffer size is inferred + from Back-to-Back Frame bursts and associated packet-loss + measurements. Therefore, sources of frame loss that are unrelated to + consistent evaluation of buffer size SHOULD be identified and removed + or mitigated. Example sources include: + + * On-path active components that are external to the DUT + + * Operating-system environment interrupting DUT operation + + * Shared-resource contention between the DUT and other off-path + component(s) impacting DUT's behavior, sometimes called the "noisy + neighbor" problem with virtualized network functions. + + Mitigations applicable to some of the sources above are discussed in + Section 6.2, with the other measurement requirements described below + in Section 6. + +6. Back-to-Back Frames + + Objective: To characterize the ability of a DUT to process Back-to- + Back Frames as defined in [RFC1242]. + + The procedure follows. + +6.1. Preparing the List of Frame Sizes + + From the list of RECOMMENDED frame sizes (Section 9 of [RFC2544]), + select the subset of frame sizes whose Measured Throughput (during + prerequisite testing) was less than the Max Theoretical Frame Rate of + the DUT/test setup. These are the only frame sizes where it is + possible to produce a burst of frames that cause the DUT buffers to + fill and eventually overflow, producing one or more discarded frames. + +6.2. Test for a Single Frame Size + + Each trial in the test requires the tester to send a burst of frames + (after idle time) with the minimum interframe gap and to count the + corresponding frames forwarded by the DUT. + + The duration of the trial includes three REQUIRED components: + + 1. The time to send the burst of frames (at the back-to-back rate), + determined by the search algorithm. + + 2. The time to receive the transferred burst of frames (at the + [RFC2544] Throughput rate), possibly truncated by buffer + overflow, and certainly including the latency of the DUT. + + 3. At least 2 seconds not overlapping the time to receive the burst + (Component 2, above), to ensure that DUT buffers have depleted. + Longer times MUST be used when conditions warrant, such as when + buffer times >2 seconds are measured or when burst sending times + are >2 seconds, but care is needed, since this time component + directly increases trial duration, and many trials and tests + comprise a complete benchmarking study. + + The upper search limit for the time to send each burst MUST be + configurable to values as high as 30 seconds (buffer time results + reported at or near the configured upper limit are likely invalid, + and the test MUST be repeated with a higher search limit). + + If all frames have been received, the tester increases the length of + the burst according to the search algorithm and performs another + trial. + + If the received frame count is less than the number of frames in the + burst, then the limit of DUT processing and buffering may have been + exceeded, and the burst length for the next trial is determined by + the search algorithm (the burst length is typically reduced, but see + below). + + Classic search algorithms have been adapted for use in benchmarking, + where the search requires discovery of a pair of outcomes, one with + no loss and another with loss, at load conditions within the + acceptable tolerance or accuracy. Conditions encountered when + benchmarking the infrastructure for network function virtualization + require algorithm enhancement. Fortunately, the adaptation of Binary + Search, and an enhanced Binary Search with Loss Verification, have + been specified in Clause 12.3 of [TST009]. These algorithms can + easily be used for Back-to-Back Frame benchmarking by replacing the + offered load level with burst length in frames. [TST009], Annex B + describes the theory behind the enhanced Binary Search with Loss + Verification algorithm. + + There are also promising works in progress that may prove useful in + Back-to-Back Frame benchmarking. [BMWG-MLRSEARCH] and + [BMWG-PLRSEARCH] are two such examples. + + Either the [TST009] Binary Search or Binary Search with Loss + Verification algorithms MUST be used, and input parameters to the + algorithm(s) MUST be reported. + + The tester usually imposes a (configurable) minimum step size for + burst length, and the step size MUST be reported with the results (as + this influences the accuracy and variation of test results). + + The original Section 26.4 of [RFC2544] definition is stated below: + + | The back-to-back value is the number of frames in the longest + | burst that the DUT will handle without the loss of any frames. + +6.3. Test Repetition and Benchmark + + On this topic, Section 26.4 of [RFC2544] requires: + + | The trial length MUST be at least 2 seconds and SHOULD be repeated + | at least 50 times with the average of the recorded values being + | reported. + + Therefore, the Back-to-Back Frame benchmark is the average of burst- + length values over repeated tests to determine the longest burst of + frames that the DUT can successfully process and buffer without frame + loss. Each of the repeated tests completes an independent search + process. + + In this update, the test MUST be repeated N times (the number of + repetitions is now a variable that must be reported) for each frame + size in the subset list, and each Back-to-Back Frame value MUST be + made available for further processing (below). + +6.4. Benchmark Calculations + + For each frame size, calculate the following summary statistics for + longest Back-to-Back Frame values over the N tests: + + * Average (Benchmark) + + * Minimum + + * Maximum + + * Standard Deviation + + Further, calculate the Implied DUT Buffer Time and the Corrected DUT + Buffer Time in seconds, as follows: + + Implied DUT buffer time = + + Average num of Back-to-back Frames / Max Theoretical Frame Rate + + The formula above is simply expressing the burst of frames in units + of time. + + The next step is to apply a correction factor that accounts for the + DUT's frame forwarding operation during the test (assuming the simple + model of the DUT composed of a buffer and a forwarding function, + described in Section 4). + + Corrected DUT Buffer Time = + / \ + Implied DUT |Implied DUT Measured Throughput | + = Buffer Time - |Buffer Time * -------------------------- | + | Max Theoretical Frame Rate | + \ / + + where: + + 1. The "Measured Throughput" is the [RFC2544] Throughput Benchmark + for the frame size tested, as augmented by methods including the + Binary Search with Loss Verification algorithm in [TST009] where + applicable and MUST be expressed in frames per second in this + equation. + + 2. The "Max Theoretical Frame Rate" is a calculated value for the + interface speed and link-layer technology used, and it MUST be + expressed in frames per second in this equation. + + 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 + by the DUT *while the burst of frames was sent in*. So, these frames + are not in the buffer, and the buffer size is more accurately + estimated by excluding them. If Measured Throughput is not + available, an acceptable approximation is the received frame rate + (see Forwarding Rate in [RFC2889] measured during Back-to-back Frame + testing). + +7. Reporting + + The Back-to-Back Frame results SHOULD be reported in the format of a + table with a row for each of the tested frame sizes. There SHOULD be + columns for the frame size and the resultant average frame count for + each type of data stream tested. + + The number of tests averaged for the benchmark, N, MUST be reported. + + The minimum, maximum, and standard deviation across all complete + tests SHOULD also be reported (they are referred to as + "Min,Max,StdDev" in Table 1). + + The Corrected DUT Buffer Time SHOULD also be reported. + + If the tester operates using a limited maximum burst length in + frames, then this maximum length SHOULD be reported. + + +=============+================+================+================+ + | Frame Size, | Ave B2B | Min,Max,StdDev | Corrected Buff | + | octets | Length, frames | | Time, Sec | + +=============+================+================+================+ + | 64 | 26000 | 25500,27000,20 | 0.00004 | + +-------------+----------------+----------------+----------------+ + + Table 1: Back-to-Back Frame Results + + Static and configuration parameters (reported with Table 1): + + * Number of test repetitions, N + + * Minimum Step Size (during searches), in frames. + + + If the tester has a specific (actual) frame rate of interest (less + than the Throughput rate), it is useful to estimate the buffer time + at that actual frame rate: + + Actual Buffer Time = + Max Theoretical Frame Rate + = Corrected DUT Buffer Time * -------------------------- + Actual Frame Rate + + and report this value, properly labeled. + +8. Security Considerations + + Benchmarking activities as described in this memo are limited to + technology characterization using controlled stimuli in a laboratory + environment, with dedicated address space and the other constraints + of [RFC2544]. + + 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. See [RFC6815]. + + Further, benchmarking is performed on an "opaque-box" (a.k.a. + "black-box") basis, relying solely on measurements observable + external to the Device or System Under Test (SUT). + + The DUT developers are commonly independent from the personnel and + institutions conducting benchmarking studies. DUT developers might + have incentives to alter the performance of the DUT if the test + conditions can be detected. Special capabilities SHOULD NOT exist in + the DUT/SUT specifically for benchmarking purposes. Procedures + described in this document are not designed to detect such activity. + Additional testing outside of the scope of this document would be + needed and has been used successfully in the past to discover such + malpractices. + + Any implications for network security arising from the DUT/SUT SHOULD + be identical in the lab and in production networks. + +9. IANA Considerations + + This document has no IANA actions. + +10. References + +10.1. Normative References + + [RFC1242] Bradner, S., "Benchmarking Terminology for Network + Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242, + July 1991, . + + [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate + Requirement Levels", BCP 14, RFC 2119, + DOI 10.17487/RFC2119, March 1997, + . + + [RFC2544] Bradner, S. and J. McQuaid, "Benchmarking Methodology for + Network Interconnect Devices", RFC 2544, + DOI 10.17487/RFC2544, March 1999, + . + + [RFC6985] Morton, A., "IMIX Genome: Specification of Variable Packet + Sizes for Additional Testing", RFC 6985, + DOI 10.17487/RFC6985, July 2013, + . + + [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC + 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, + May 2017, . + + [RFC8239] Avramov, L. and J. Rapp, "Data Center Benchmarking + Methodology", RFC 8239, DOI 10.17487/RFC8239, August 2017, + . + + [TST009] ETSI, "Network Functions Virtualisation (NFV) Release 3; + Testing; Specification of Networking Benchmarks and + Measurement Methods for NFVI", Rapporteur: A. Morton, ETSI + GS NFV-TST 009 v3.4.1, December 2020, + . + +10.2. Informative References + + [BMWG-MLRSEARCH] + Konstantynowicz, M., Ed. and V. Polák, Ed., "Multiple Loss + Ratio Search for Packet Throughput (MLRsearch)", Work in + Progress, Internet-Draft, draft-ietf-bmwg-mlrsearch-00, 9 + February 2021, . + + [BMWG-PLRSEARCH] + Konstantynowicz, M., Ed. and V. Polák, Ed., "Probabilistic + Loss Ratio Search for Packet Throughput (PLRsearch)", Work + in Progress, Internet-Draft, draft-vpolak-bmwg-plrsearch- + 03, 6 March 2020, . + + [OPNFV-2017] + Cooper, T., Rao, S., and A. Morton, "Dataplane + Performance, Capacity, and Benchmarking in OPNFV", 15 June + 2017, + . + + [RFC1944] Bradner, S. and J. McQuaid, "Benchmarking Methodology for + Network Interconnect Devices", RFC 1944, + DOI 10.17487/RFC1944, May 1996, + . + + [RFC2889] Mandeville, R. and J. Perser, "Benchmarking Methodology + for LAN Switching Devices", RFC 2889, + DOI 10.17487/RFC2889, August 2000, + . + + [RFC5180] Popoviciu, C., Hamza, A., Van de Velde, G., and D. + Dugatkin, "IPv6 Benchmarking Methodology for Network + Interconnect Devices", RFC 5180, DOI 10.17487/RFC5180, May + 2008, . + + [RFC6201] Asati, R., Pignataro, C., Calabria, F., and C. Olvera, + "Device Reset Characterization", RFC 6201, + DOI 10.17487/RFC6201, March 2011, + . + + [RFC6815] Bradner, S., Dubray, K., McQuaid, J., and A. Morton, + "Applicability Statement for RFC 2544: Use on Production + Networks Considered Harmful", RFC 6815, + DOI 10.17487/RFC6815, November 2012, + . + + [VSPERF-b2b] + Morton, A., "Back2Back Testing Time Series (from CI)", May + 2021, . + + [VSPERF-BSLV] + Rao, S. and A. Morton, "Evolution of Repeatability in + Benchmarking: Fraser Plugfest (Summary for IETF BMWG)", + July 2018, + . + + [VSPERF-CI] + Tahhan, M., "OPNFV VSPERF CI", September 2019, + . + +Acknowledgments + + Thanks to Trevor Cooper, Sridhar Rao, and Martin Klozik of the VSPERF + project for many contributions to the early testing [VSPERF-b2b]. + Yoshiaki Itou has also investigated the topic and made useful + suggestions. Maciek Konstantyowicz and Vratko Polák also provided + many comments and suggestions based on extensive integration testing + and resulting search-algorithm proposals -- the most up-to-date + feedback possible. Tim Carlin also provided comments and support for + the document. Warren Kumari's review improved readability in several + key passages. David Black, Martin Duke, and Scott Bradner's comments + improved the clarity and configuration advice on trial duration. + Mališa Vučinić suggested additional text on DUT design cautions in + the Security Considerations section. + +Author's Address + + Al Morton + AT&T Labs + 200 Laurel Avenue South + Middletown, NJ 07748 + United States of America + + Phone: +1 732 420 1571 + Email: acmorton@att.com -- cgit v1.2.3