path: root/doc/rfc/rfc7640.txt

Internet Engineering Task Force (IETF)                    B. Constantine
Request for Comments: 7640                                          JDSU
Category: Informational                                      R. Krishnan
ISSN: 2070-1721                                                Dell Inc.
                                                          September 2015


                    Traffic Management Benchmarking

Abstract

   This framework describes a practical methodology for benchmarking the
   traffic management capabilities of networking devices (i.e.,
   policing, shaping, etc.).  The goals are to provide a repeatable test
   method that objectively compares performance of the device's traffic
   management capabilities and to specify the means to benchmark traffic
   management with representative application traffic.

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 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7640.

Copyright Notice

   Copyright (c) 2015 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
   (http://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.



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Table of Contents

   1. Introduction ....................................................3
      1.1. Traffic Management Overview ................................3
      1.2. Lab Configuration and Testing Overview .....................5
   2. Conventions Used in This Document ...............................6
   3. Scope and Goals .................................................7
   4. Traffic Benchmarking Metrics ...................................10
      4.1. Metrics for Stateless Traffic Tests .......................10
      4.2. Metrics for Stateful Traffic Tests ........................12
   5. Tester Capabilities ............................................13
      5.1. Stateless Test Traffic Generation .........................13
           5.1.1. Burst Hunt with Stateless Traffic ..................14
      5.2. Stateful Test Pattern Generation ..........................14
           5.2.1. TCP Test Pattern Definitions .......................15
   6. Traffic Benchmarking Methodology ...............................17
      6.1. Policing Tests ............................................17
           6.1.1. Policer Individual Tests ...........................18
           6.1.2. Policer Capacity Tests .............................19
                  6.1.2.1. Maximum Policers on Single Physical Port ..20
                  6.1.2.2. Single Policer on All Physical Ports ......22
                  6.1.2.3. Maximum Policers on All Physical Ports ....22
      6.2. Queue/Scheduler Tests .....................................23
           6.2.1. Queue/Scheduler Individual Tests ...................23
                  6.2.1.1. Testing Queue/Scheduler with
                           Stateless Traffic .........................23
                  6.2.1.2. Testing Queue/Scheduler with
                           Stateful Traffic ..........................25
           6.2.2. Queue/Scheduler Capacity Tests .....................28
                  6.2.2.1. Multiple Queues, Single Port Active .......28
                           6.2.2.1.1. Strict Priority on
                                      Egress Port ....................28
                           6.2.2.1.2. Strict Priority + WFQ on
                                      Egress Port ....................29
                  6.2.2.2. Single Queue per Port, All Ports Active ...30
                  6.2.2.3. Multiple Queues per Port, All
                           Ports Active ..............................31
      6.3. Shaper Tests ..............................................32
           6.3.1. Shaper Individual Tests ............................32
                  6.3.1.1. Testing Shaper with Stateless Traffic .....33
                  6.3.1.2. Testing Shaper with Stateful Traffic ......34
           6.3.2. Shaper Capacity Tests ..............................36
                  6.3.2.1. Single Queue Shaped, All Physical
                           Ports Active ..............................37
                  6.3.2.2. All Queues Shaped, Single Port Active .....37
                  6.3.2.3. All Queues Shaped, All Ports Active .......39





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      6.4. Concurrent Capacity Load Tests ............................40
   7. Security Considerations ........................................40
   8. References .....................................................41
      8.1. Normative References ......................................41
      8.2. Informative References ....................................42
   Appendix A. Open Source Tools for Traffic Management Testing ......44
   Appendix B. Stateful TCP Test Patterns ............................45
   Acknowledgments ...................................................51
   Authors' Addresses ................................................51

1.  Introduction

   Traffic management (i.e., policing, shaping, etc.) is an increasingly
   important component when implementing network Quality of Service
   (QoS).

   There is currently no framework to benchmark these features, although
   some standards address specific areas as described in Section 1.1.

   This document provides a framework to conduct repeatable traffic
   management benchmarks for devices and systems in a lab environment.

   Specifically, this framework defines the methods to characterize the
   capacity of the following traffic management features in network
   devices: classification, policing, queuing/scheduling, and traffic
   shaping.

   This benchmarking framework can also be used as a test procedure to
   assist in the tuning of traffic management parameters before service
   activation.  In addition to Layer 2/3 (Ethernet/IP) benchmarking,
   Layer 4 (TCP) test patterns are proposed by this document in order to
   more realistically benchmark end-user traffic.

1.1.  Traffic Management Overview

   In general, a device with traffic management capabilities performs
   the following functions:

   -  Traffic classification: identifies traffic according to various
      configuration rules (for example, IEEE 802.1Q Virtual LAN (VLAN),
      Differentiated Services Code Point (DSCP)) and marks this traffic
      internally to the network device.  Multiple external priorities
      (DSCP, 802.1p, etc.) can map to the same priority in the device.

   -  Traffic policing: limits the rate of traffic that enters a network
      device according to the traffic classification.  If the traffic
      exceeds the provisioned limits, the traffic is either dropped or
      remarked and forwarded onto the next network device.



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   -  Traffic scheduling: provides traffic classification within the
      network device by directing packets to various types of queues and
      applies a dispatching algorithm to assign the forwarding sequence
      of packets.

   -  Traffic shaping: controls traffic by actively buffering and
      smoothing the output rate in an attempt to adapt bursty traffic to
      the configured limits.

   -  Active Queue Management (AQM): involves monitoring the status of
      internal queues and proactively dropping (or remarking) packets,
      which causes hosts using congestion-aware protocols to "back off"
      and in turn alleviate queue congestion [RFC7567].  On the other
      hand, classic traffic management techniques reactively drop (or
      remark) packets based on queue-full conditions.  The benchmarking
      scenarios for AQM are different and are outside the scope of this
      testing framework.

   Even though AQM is outside the scope of this framework, it should be
   noted that the TCP metrics and TCP test patterns (defined in
   Sections 4.2 and 5.2, respectively) could be useful to test new AQM
   algorithms (targeted to alleviate "bufferbloat").  Examples of these
   algorithms include Controlled Delay [CoDel] and Proportional Integral
   controller Enhanced [PIE].

   The following diagram is a generic model of the traffic management
   capabilities within a network device.  It is not intended to
   represent all variations of manufacturer traffic management
   capabilities, but it provides context for this test framework.

    |----------|   |----------------|   |--------------|   |----------|
    |          |   |                |   |              |   |          |
    |Interface |   |Ingress Actions |   |Egress Actions|   |Interface |
    |Ingress   |   |(classification,|   |(scheduling,  |   |Egress    |
    |Queues    |   | marking,       |   | shaping,     |   |Queues    |
    |          |-->| policing, or   |-->| active queue |-->|          |
    |          |   | shaping)       |   | management,  |   |          |
    |          |   |                |   | remarking)   |   |          |
    |----------|   |----------------|   |--------------|   |----------|

   Figure 1: Generic Traffic Management Capabilities of a Network Device

   Ingress actions such as classification are defined in [RFC4689] and
   include IP addresses, port numbers, and DSCP.  In terms of marking,
   [RFC2697] and [RFC2698] define a Single Rate Three Color Marker and a
   Two Rate Three Color Marker, respectively.





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   The Metro Ethernet Forum (MEF) specifies policing and shaping in
   terms of ingress and egress subscriber/provider conditioning
   functions as described in MEF 12.2 [MEF-12.2], as well as ingress and
   bandwidth profile attributes as described in MEF 10.3 [MEF-10.3] and
   MEF 26.1 [MEF-26.1].

1.2.  Lab Configuration and Testing Overview

   The following diagram shows the lab setup for the traffic management
   tests:

     +--------------+     +-------+     +----------+    +-----------+
     | Transmitting |     |       |     |          |    | Receiving |
     | Test Host    |     |       |     |          |    | Test Host |
     |              |-----| Device|---->| Network  |--->|           |
     |              |     | Under |     | Delay    |    |           |
     |              |     | Test  |     | Emulator |    |           |
     |              |<----|       |<----|          |<---|           |
     |              |     |       |     |          |    |           |
     +--------------+     +-------+     +----------+    +-----------+

             Figure 2: Lab Setup for Traffic Management Tests

   As shown in the test diagram, the framework supports unidirectional
   and bidirectional traffic management tests (where the transmitting
   and receiving roles would be reversed on the return path).

   This testing framework describes the tests and metrics for each of
   the following traffic management functions:

   -  Classification

   -  Policing

   -  Queuing/scheduling

   -  Shaping

   The tests are divided into individual and rated capacity tests.  The
   individual tests are intended to benchmark the traffic management
   functions according to the metrics defined in Section 4.  The
   capacity tests verify traffic management functions under the load of
   many simultaneous individual tests and their flows.

   This involves concurrent testing of multiple interfaces with the
   specific traffic management function enabled, and increasing the load
   to the capacity limit of each interface.




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   For example, a device is specified to be capable of shaping on all of
   its egress ports.  The individual test would first be conducted to
   benchmark the specified shaping function against the metrics defined
   in Section 4.  Then, the capacity test would be executed to test the
   shaping function concurrently on all interfaces and with maximum
   traffic load.

   The Network Delay Emulator (NDE) is required for TCP stateful tests
   in order to allow TCP to utilize a TCP window of significant size in
   its control loop.

   Note also that the NDE SHOULD be passive in nature (e.g., a fiber
   spool).  This is recommended to eliminate the potential effects that
   an active delay element (i.e., test impairment generator) may have on
   the test flows.  In the case where a fiber spool is not practical due
   to the desired latency, an active NDE MUST be independently verified
   to be capable of adding the configured delay without loss.  In other
   words, the Device Under Test (DUT) would be removed and the NDE
   performance benchmarked independently.

   Note that the NDE SHOULD be used only as emulated delay.  Most NDEs
   allow for per-flow delay actions, emulating QoS prioritization.  For
   this framework, the NDE's sole purpose is simply to add delay to all
   packets (emulate network latency).  So, to benchmark the performance
   of the NDE, the maximum offered load should be tested against the
   following frame sizes: 128, 256, 512, 768, 1024, 1500, and
   9600 bytes.  The delay accuracy at each of these packet sizes can
   then be used to calibrate the range of expected Bandwidth-Delay
   Product (BDP) for the TCP stateful tests.

2.  Conventions Used in This Document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC2119].

   The following acronyms are used:

      AQM: Active Queue Management

      BB: Bottleneck Bandwidth

      BDP: Bandwidth-Delay Product

      BSA: Burst Size Achieved

      CBS: Committed Burst Size




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      CIR: Committed Information Rate

      DUT: Device Under Test

      EBS: Excess Burst Size

      EIR: Excess Information Rate

      NDE: Network Delay Emulator

      QL: Queue Length

      QoS: Quality of Service

      RTT: Round-Trip Time

      SBB: Shaper Burst Bytes

      SBI: Shaper Burst Interval

      SP: Strict Priority

      SR: Shaper Rate

      SSB: Send Socket Buffer

      SUT: System Under Test

      Ti: Transmission Interval

      TTP: TCP Test Pattern

      TTPET: TCP Test Pattern Execution Time

3.  Scope and Goals

   The scope of this work is to develop a framework for benchmarking and
   testing the traffic management capabilities of network devices in the
   lab environment.  These network devices may include but are not
   limited to:

   -  Switches (including Layer 2/3 devices)

   -  Routers

   -  Firewalls

   -  General Layer 4-7 appliances (Proxies, WAN Accelerators, etc.)



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   Essentially, any network device that performs traffic management as
   defined in Section 1.1 can be benchmarked or tested with this
   framework.

   The primary goal is to assess the maximum forwarding performance
   deemed to be within the provisioned traffic limits that a network
   device can sustain without dropping or impairing packets, and without
   compromising the accuracy of multiple instances of traffic management
   functions.  This is the benchmark for comparison between devices.

   Within this framework, the metrics are defined for each traffic
   management test but do not include pass/fail criteria, which are not
   within the charter of the BMWG.  This framework provides the test
   methods and metrics to conduct repeatable testing, which will provide
   the means to compare measured performance between DUTs.

   As mentioned in Section 1.2, these methods describe the individual
   tests and metrics for several management functions.  It is also
   within scope that this framework will benchmark each function in
   terms of overall rated capacity.  This involves concurrent testing of
   multiple interfaces with the specific traffic management function
   enabled, up to the capacity limit of each interface.

   It is not within the scope of this framework to specify the procedure
   for testing multiple configurations of traffic management functions
   concurrently.  The multitudes of possible combinations are almost
   unbounded, and the ability to identify functional "break points"
   would be almost impossible.

   However, Section 6.4 provides suggestions for some profiles of
   concurrent functions that would be useful to benchmark.  The key
   requirement for any concurrent test function is that tests MUST
   produce reliable and repeatable results.

   Also, it is not within scope to perform conformance testing.  Tests
   defined in this framework benchmark the traffic management functions
   according to the metrics defined in Section 4 and do not address any
   conformance to standards related to traffic management.

   The current specifications don't specify exact behavior or
   implementation, and the specifications that do exist (cited in
   Section 1.1) allow implementations to vary with regard to short-term
   rate accuracy and other factors.  This is a primary driver for this
   framework: to provide an objective means to compare vendor traffic
   management functions.






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   Another goal is to devise methods that utilize flows with congestion-
   aware transport (TCP) as part of the traffic load and still produce
   repeatable results in the isolated test environment.  This framework
   will derive stateful test patterns (TCP or application layer) that
   can also be used to further benchmark the performance of applicable
   traffic management techniques such as queuing/scheduling and traffic
   shaping.  In cases where the network device is stateful in nature
   (i.e., firewall, etc.), stateful test pattern traffic is important to
   test, along with stateless UDP traffic in specific test scenarios
   (i.e., applications using TCP transport and UDP VoIP, etc.).

   As mentioned earlier in this document, repeatability of test results
   is critical, especially considering the nature of stateful TCP
   traffic.  To this end, the stateful tests will use TCP test patterns
   to emulate applications.  This framework also provides guidelines for
   application modeling and open source tools to achieve the repeatable
   stimulus.  Finally, TCP metrics from [RFC6349] MUST be measured for
   each stateful test and provide the means to compare each repeated
   test.

   Even though this framework targets the testing of TCP applications
   (i.e., web, email, database, etc.), it could also be applied to the
   Stream Control Transmission Protocol (SCTP) in terms of test
   patterns.  WebRTC, Signaling System 7 (SS7) signaling, and 3GPP are
   SCTP-based applications that could be modeled with this framework to
   benchmark SCTP's effect on traffic management performance.

   Note that at the time of this writing, this framework does not
   address tcpcrypt (encrypted TCP) test patterns, although the metrics
   defined in Section 4.2 can still be used because the metrics are
   based on TCP retransmission and RTT measurements (versus any of the
   payload).  Thus, if tcpcrypt becomes popular, it would be natural for
   benchmarkers to consider encrypted TCP patterns and include them in
   test cases.

















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4.  Traffic Benchmarking Metrics

   The metrics to be measured during the benchmarks are divided into two
   (2) sections: packet-layer metrics used for the stateless traffic
   testing and TCP-layer metrics used for the stateful traffic testing.

4.1.  Metrics for Stateless Traffic Tests

   Stateless traffic measurements require that a sequence number and
   timestamp be inserted into the payload for lost-packet analysis.
   Delay analysis may be achieved by insertion of timestamps directly
   into the packets or timestamps stored elsewhere (packet captures).
   This framework does not specify the packet format to carry sequence
   number or timing information.

   However, [RFC4737] and [RFC4689] provide recommendations for sequence
   tracking, along with definitions of in-sequence and out-of-order
   packets.

   The following metrics MUST be measured during the stateless traffic
   benchmarking components of the tests:

   -  Burst Size Achieved (BSA): For the traffic policing and network
      queue tests, the tester will be configured to send bursts to test
      either the Committed Burst Size (CBS) or Excess Burst Size (EBS)
      of a policer or the queue/buffer size configured in the DUT.  The
      BSA metric is a measure of the actual burst size received at the
      egress port of the DUT with no lost packets.  For example, the
      configured CBS of a DUT is 64 KB, and after the burst test, only a
      63 KB burst can be achieved without packet loss.  Then, 63 KB is
      the BSA.  Also, the average Packet Delay Variation (PDV) (see
      below) as experienced by the packets sent at the BSA burst size
      should be recorded.  This metric SHALL be reported in units of
      bytes, KB, or MB.

   -  Lost Packets (LP): For all traffic management tests, the tester
      will transmit the test packets into the DUT ingress port, and the
      number of packets received at the egress port will be measured.
      The difference between packets transmitted into the ingress port
      and received at the egress port is the number of lost packets as
      measured at the egress port.  These packets must have unique
      identifiers such that only the test packets are measured.  For
      cases where multiple flows are transmitted from the ingress port
      to the egress port (e.g., IP conversations), each flow must have
      sequence numbers within the stream of test packets.






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   [RFC6703] and [RFC2680] describe the need to establish the time
   threshold to wait before a packet is declared as lost.  This
   threshold MUST be reported, with the results reported as an integer
   number that cannot be negative.

   -  Out-of-Sequence (OOS): In addition to the LP metric, the test
      packets must be monitored for sequence.  [RFC4689] defines the
      general function of sequence tracking, as well as definitions for
      in-sequence and out-of-order packets.  Out-of-order packets will
      be counted per [RFC4737].  This metric SHALL be reported as an
      integer number that cannot be negative.

   -  Packet Delay (PD): The PD metric is the difference between the
      timestamp of the received egress port packets and the packets
      transmitted into the ingress port, as specified in [RFC1242].  The
      transmitting host and receiving host time must be in time sync
      (achieved by using NTP, GPS, etc.).  This metric SHALL be reported
      as a real number of seconds, where a negative measurement usually
      indicates a time synchronization problem between test devices.

   -  Packet Delay Variation (PDV): The PDV metric is the variation
      between the timestamp of the received egress port packets, as
      specified in [RFC5481].  Note that per [RFC5481], this PDV is the
      variation of one-way delay across many packets in the traffic
      flow.  Per the measurement formula in [RFC5481], select the high
      percentile of 99%, and units of measure will be a real number of
      seconds (a negative value is not possible for the PDV and would
      indicate a measurement error).

   -  Shaper Rate (SR): The SR represents the average DUT output rate
      (bps) over the test interval.  The SR is only applicable to the
      traffic-shaping tests.

   -  Shaper Burst Bytes (SBB): A traffic shaper will emit packets in
      "trains" of different sizes; these frames are emitted "back-to-
      back" with respect to the mandatory interframe gap.  This metric
      characterizes the method by which the shaper emits traffic.  Some
      shapers transmit larger bursts per interval, and a burst of
      one packet would apply to the less common case of a shaper sending
      a constant-bitrate stream of single packets.  This metric SHALL be
      reported in units of bytes, KB, or MB.  The SBB metric is only
      applicable to the traffic-shaping tests.

   -  Shaper Burst Interval (SBI): The SBI is the time between bursts
      emitted by the shaper and is measured at the DUT egress port.
      This metric SHALL be reported as a real number of seconds.  The
      SBI is only applicable to the traffic-shaping tests.




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4.2.  Metrics for Stateful Traffic Tests

   The stateful metrics will be based on [RFC6349] TCP metrics and MUST
   include:

   -  TCP Test Pattern Execution Time (TTPET): [RFC6349] defined the TCP
      Transfer Time for bulk transfers, which is simply the measured
      time to transfer bytes across single or concurrent TCP
      connections.  The TCP test patterns used in traffic management
      tests will include bulk transfer and interactive applications.
      The interactive patterns include instances such as HTTP business
      applications and database applications.  The TTPET will be the
      measure of the time for a single execution of a TCP Test Pattern
      (TTP).  Average, minimum, and maximum times will be measured or
      calculated and expressed as a real number of seconds.

   An example would be an interactive HTTP TTP session that should take
   5 seconds on a GigE network with 0.5-millisecond latency.  During ten
   (10) executions of this TTP, the TTPET results might be an average of
   6.5 seconds, a minimum of 5.0 seconds, and a maximum of 7.9 seconds.

   -  TCP Efficiency: After the execution of the TTP, TCP Efficiency
      represents the percentage of bytes that were not retransmitted.

                         Transmitted Bytes - Retransmitted Bytes
     TCP Efficiency % =  ---------------------------------------  X 100
                                  Transmitted Bytes

   "Transmitted Bytes" is the total number of TCP bytes to be
   transmitted, including the original bytes and the retransmitted
   bytes.  To avoid any misinterpretation that a reordered packet is a
   retransmitted packet (as may be the case with packet decode
   interpretation), these retransmitted bytes should be recorded from
   the perspective of the sender's TCP/IP stack.

   -  Buffer Delay: Buffer Delay represents the increase in RTT during a
      TCP test versus the baseline DUT RTT (non-congested, inherent
      latency).  RTT and the technique to measure RTT (average versus
      baseline) are defined in [RFC6349].  Referencing [RFC6349], the
      average RTT is derived from the total of all measured RTTs during
      the actual test sampled at every second divided by the test
      duration in seconds.









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                                      Total RTTs during transfer
     Average RTT during transfer =  ------------------------------
                                     Transfer duration in seconds


                     Average RTT during transfer - Baseline RTT
   Buffer Delay % =  ------------------------------------------  X 100
                                 Baseline RTT

   Note that even though this was not explicitly stated in [RFC6349],
   retransmitted packets should not be used in RTT measurements.

   Also, the test results should record the average RTT in milliseconds
   across the entire test duration, as well as the number of samples.

5.  Tester Capabilities

   The testing capabilities of the traffic management test environment
   are divided into two (2) sections: stateless traffic testing and
   stateful traffic testing.

5.1.  Stateless Test Traffic Generation

   The test device MUST be capable of generating traffic at up to the
   link speed of the DUT.  The test device must be calibrated to verify
   that it will not drop any packets.  The test device's inherent PD and
   PDV must also be calibrated and subtracted from the PD and PDV
   metrics.  The test device must support the encapsulation to be
   tested, e.g., IEEE 802.1Q VLAN, IEEE 802.1ad Q-in-Q, Multiprotocol
   Label Switching (MPLS).  Also, the test device must allow control of
   the classification techniques defined in [RFC4689] (e.g., IP address,
   DSCP, classification of Type of Service).

   The open source tool "iperf" can be used to generate stateless UDP
   traffic and is discussed in Appendix A.  Since iperf is a software-
   based tool, there will be performance limitations at higher link
   speeds (e.g., 1 GigE, 10 GigE).  Careful calibration of any test
   environment using iperf is important.  At higher link speeds, using
   hardware-based packet test equipment is recommended.












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5.1.1.  Burst Hunt with Stateless Traffic

   A central theme for the traffic management tests is to benchmark the
   specified burst parameter of a traffic management function, since
   burst parameters listed in Service Level Agreements (SLAs) are
   specified in bytes.  For testing efficiency, including a burst hunt
   feature is recommended, as this feature automates the manual process
   of determining the maximum burst size that can be supported by a
   traffic management function.

   The burst hunt algorithm should start at the target burst size
   (maximum burst size supported by the traffic management function) and
   will send single bursts until it can determine the largest burst that
   can pass without loss.  If the target burst size passes, then the
   test is complete.  The "hunt" aspect occurs when the target burst
   size is not achieved; the algorithm will drop down to a configured
   minimum burst size and incrementally increase the burst until the
   maximum burst supported by the DUT is discovered.  The recommended
   granularity of the incremental burst size increase is 1 KB.

   For a policer function, if the burst size passes, the burst should be
   increased by increments of 1 KB to verify that the policer is truly
   configured properly (or enabled at all).

5.2.  Stateful Test Pattern Generation

   The TCP test host will have many of the same attributes as the TCP
   test host defined in [RFC6349].  The TCP test device may be a
   standard computer or a dedicated communications test instrument.  In
   both cases, it must be capable of emulating both a client and a
   server.

   For any test using stateful TCP test traffic, the Network Delay
   Emulator (the NDE function as shown in the lab setup diagram in
   Section 1.2) must be used in order to provide a meaningful BDP.  As
   discussed in Section 1.2, the target traffic rate and configured RTT
   MUST be verified independently, using just the NDE for all stateful
   tests (to ensure that the NDE can add delay without inducing any
   packet loss).

   The TCP test host MUST be capable of generating and receiving
   stateful TCP test traffic at the full link speed of the DUT.  As a
   general rule of thumb, testing TCP throughput at rates greater than
   500 Mbps may require high-performance server hardware or dedicated
   hardware-based test tools.






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   The TCP test host MUST allow the adjustment of both Send and Receive
   Socket Buffer sizes.  The Socket Buffers must be large enough to fill
   the BDP for bulk transfer of TCP test application traffic.

   Measuring RTT and retransmissions per connection will generally
   require a dedicated communications test instrument.  In the absence
   of dedicated hardware-based test tools, these measurements may need
   to be conducted with packet capture tools; i.e., conduct TCP
   throughput tests, and analyze RTT and retransmissions in packet
   captures.

   The TCP implementation used by the test host MUST be specified in the
   test results (e.g., TCP New Reno, TCP options supported).
   Additionally, the test results SHALL provide specific congestion
   control algorithm details, as per [RFC3148].

   While [RFC6349] defined the means to conduct throughput tests of TCP
   bulk transfers, the traffic management framework will extend TCP test
   execution into interactive TCP application traffic.  Examples include
   email, HTTP, and business applications.  This interactive traffic is
   bidirectional and can be chatty, meaning many turns in traffic
   communication during the course of a transaction (versus the
   relatively unidirectional flow of bulk transfer applications).

   The test device must not only support bulk TCP transfer application
   traffic but MUST also support chatty traffic.  A valid stress test
   SHOULD include both traffic types.  This is due to the non-uniform,
   bursty nature of chatty applications versus the relatively uniform
   nature of bulk transfers (the bulk transfer smoothly stabilizes to
   equilibrium state under lossless conditions).

   While iperf is an excellent choice for TCP bulk transfer testing, the
   "netperf" open source tool provides the ability to control client and
   server request/response behavior.  The netperf-wrapper tool is a
   Python script that runs multiple simultaneous netperf instances and
   aggregates the results.  Appendix A provides an overview of
   netperf/netperf-wrapper, as well as iperf.  As with any software-
   based tool, the performance must be qualified to the link speed to be
   tested.  Hardware-based test equipment should be considered for
   reliable results at higher link speeds (e.g., 1 GigE, 10 GigE).

5.2.1.  TCP Test Pattern Definitions

   As mentioned in the goals of this framework, techniques are defined
   to specify TCP traffic test patterns to benchmark traffic management
   technique(s) and produce repeatable results.  Some network devices,
   such as firewalls, will not process stateless test traffic; this is
   another reason why stateful TCP test traffic must be used.



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   An application could be fully emulated up to Layer 7; however, this
   framework proposes that stateful TCP test patterns be used in order
   to provide granular and repeatable control for the benchmarks.  The
   following diagram illustrates a simple web-browsing application
   (HTTP).

                             GET URL

             Client      ------------------------->   Web
                                                  |
             Web             200 OK        100 ms |
                                                  |
             Browser     <-------------------------   Server

            Figure 3: Simple Flow Diagram for a Web Application

   In this example, the Client Web Browser (client) requests a URL, and
   then the Web Server delivers the web page content to the client
   (after a server delay of 100 milliseconds).  This asynchronous
   "request/response" behavior is intrinsic to most TCP-based
   applications, such as email (SMTP), file transfers (FTP and Server
   Message Block (SMB)), database (SQL), web applications (SOAP), and
   Representational State Transfer (REST).  The impact on the network
   elements is due to the multitudes of clients and the variety of
   bursty traffic, which stress traffic management functions.  The
   actual emulation of the specific application protocols is not
   required, and TCP test patterns can be defined to mimic the
   application network traffic flows and produce repeatable results.

   Application modeling techniques have been proposed in
   [3GPP2-C_R1002-A], which provides examples to model the behavior of
   HTTP, FTP, and Wireless Application Protocol (WAP) applications at
   the TCP layer.  The models have been defined with various
   mathematical distributions for the request/response bytes and
   inter-request gap times.  The model definition formats described in
   [3GPP2-C_R1002-A] are the basis for the guidelines provided in
   Appendix B and are also similar to formats used by network modeling
   tools.  Packet captures can also be used to characterize application
   traffic and specify some of the test patterns listed in Appendix B.

   This framework does not specify a fixed set of TCP test patterns but
   does provide test cases that SHOULD be performed; see Appendix B.
   Some of these examples reflect those specified in [CA-Benchmark],
   which suggests traffic mixes for a variety of representative
   application profiles.  Other examples are simply well-known
   application traffic types such as HTTP.





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6.  Traffic Benchmarking Methodology

   The traffic benchmarking methodology uses the test setup from
   Section 1.2 and metrics defined in Section 4.

   Each test SHOULD compare the network device's internal statistics
   (available via command line management interface, SNMP, etc.) to the
   measured metrics defined in Section 4.  This evaluates the accuracy
   of the internal traffic management counters under individual test
   conditions and capacity test conditions as defined in Sections 4.1
   and 4.2.  This comparison is not intended to compare real-time
   statistics, but rather the cumulative statistics reported after the
   test has completed and device counters have updated (it is common for
   device counters to update after an interval of 10 seconds or more).

   From a device configuration standpoint, scheduling and shaping
   functionality can be applied to logical ports (e.g., Link Aggregation
   (LAG)).  This would result in the same scheduling and shaping
   configuration applied to all of the member physical ports.  The focus
   of this document is only on tests at a physical-port level.

   The following sections provide the objective, procedure, metrics, and
   reporting format for each test.  For all test steps, the following
   global parameters must be specified:

      Test Runs (Tr):
         The number of times the test needs to be run to ensure accurate
         and repeatable results.  The recommended value is a minimum
         of 10.

      Test Duration (Td):
         The duration of a test iteration, expressed in seconds.  The
         recommended minimum value is 60 seconds.

   The variability in the test results MUST be measured between test
   runs, and if the variation is characterized as a significant portion
   of the measured values, the next step may be to revise the methods to
   achieve better consistency.

6.1.  Policing Tests

   A policer is defined as the entity performing the policy function.
   The intent of the policing tests is to verify the policer performance
   (i.e., CIR/CBS and EIR/EBS parameters).  The tests will verify that
   the network device can handle the CIR with CBS and the EIR with EBS,
   and will use back-to-back packet-testing concepts as described in
   [RFC2544] (but adapted to burst size algorithms and terminology).
   Also, [MEF-14], [MEF-19], and [MEF-37] provide some bases for



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   specific components of this test.  The burst hunt algorithm defined
   in Section 5.1.1 can also be used to automate the measurement of the
   CBS value.

   The tests are divided into two (2) sections: individual policer tests
   and then full-capacity policing tests.  It is important to benchmark
   the basic functionality of the individual policer and then proceed
   into the fully rated capacity of the device.  This capacity may
   include the number of policing policies per device and the number of
   policers simultaneously active across all ports.

6.1.1.  Policer Individual Tests

   Objective:
      Test a policer as defined by [RFC4115] or [MEF-10.3], depending
      upon the equipment's specification.  In addition to verifying that
      the policer allows the specified CBS and EBS bursts to pass, the
      policer test MUST verify that the policer will remark or drop
      excess packets, and pass traffic at the specified CBS/EBS values.

   Test Summary:
      Policing tests should use stateless traffic.  Stateful TCP test
      traffic will generally be adversely affected by a policer in the
      absence of traffic shaping.  So, while TCP traffic could be used,
      it is more accurate to benchmark a policer with stateless traffic.

      As an example of a policer as defined by [RFC4115], consider a
      CBS/EBS of 64 KB and CIR/EIR of 100 Mbps on a 1 GigE physical link
      (in color-blind mode).  A stateless traffic burst of 64 KB would
      be sent into the policer at the GigE rate.  This equates to an
      approximately 0.512-millisecond burst time (64 KB at 1 GigE).  The
      traffic generator must space these bursts to ensure that the
      aggregate throughput does not exceed the CIR.  The Ti between the
      bursts would equal CBS * 8 / CIR = 5.12 milliseconds in this
      example.

   Test Metrics:
      The metrics defined in Section 4.1 (BSA, LP, OOS, PD, and PDV)
      SHALL be measured at the egress port and recorded.

   Procedure:
      1. Configure the DUT policing parameters for the desired CIR/EIR
         and CBS/EBS values to be tested.

      2. Configure the tester to generate a stateless traffic burst
         equal to CBS and an interval equal to Ti (CBS in bits/CIR).





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      3. Compliant Traffic Test: Generate bursts of CBS + EBS traffic
         into the policer ingress port, and measure the metrics defined
         in Section 4.1 (BSA, LP, OOS, PD, and PDV) at the egress port
         and across the entire Td (default 60-second duration).

      4. Excess Traffic Test: Generate bursts of greater than CBS + EBS
         bytes into the policer ingress port, and verify that the
         policer only allowed the BSA bytes to exit the egress.  The
         excess burst MUST be recorded; the recommended value is
         1000 bytes.  Additional tests beyond the simple color-blind
         example might include color-aware mode, configurations where
         EIR is greater than CIR, etc.

   Reporting Format:
      The policer individual report MUST contain all results for each
      CIR/EIR/CBS/EBS test run.  A recommended format is as follows:

      ***********************************************************

      Test Configuration Summary: Tr, Td

      DUT Configuration Summary: CIR, EIR, CBS, EBS

      The results table should contain entries for each test run,
      as follows (Test #1 to Test #Tr):

      -  Compliant Traffic Test: BSA, LP, OOS, PD, and PDV

      -  Excess Traffic Test: BSA

      ***********************************************************

6.1.2.  Policer Capacity Tests

   Objective:
      The intent of the capacity tests is to verify the policer
      performance in a scaled environment with multiple ingress customer
      policers on multiple physical ports.  This test will benchmark the
      maximum number of active policers as specified by the device
      manufacturer.

   Test Summary:
      The specified policing function capacity is generally expressed in
      terms of the number of policers active on each individual physical
      port as well as the number of unique policer rates that are
      utilized.  For all of the capacity tests, the benchmarking test





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      procedure and reporting format described in Section 6.1.1 for a
      single policer MUST be applied to each of the physical-port
      policers.

      For example, a Layer 2 switching device may specify that each of
      the 32 physical ports can be policed using a pool of policing
      service policies.  The device may carry a single customer's
      traffic on each physical port, and a single policer is
      instantiated per physical port.  Another possibility is that a
      single physical port may carry multiple customers, in which case
      many customer flows would be policed concurrently on an individual
      physical port (separate policers per customer on an individual
      port).

   Test Metrics:
      The metrics defined in Section 4.1 (BSA, LP, OOS, PD, and PDV)
      SHALL be measured at the egress port and recorded.

   The following sections provide the specific test scenarios,
   procedures, and reporting formats for each policer capacity test.

6.1.2.1.  Maximum Policers on Single Physical Port

   Test Summary:
      The first policer capacity test will benchmark a single physical
      port, with maximum policers on that physical port.

      Assume multiple categories of ingress policers at rates
      r1, r2, ..., rn.  There are multiple customers on a single
      physical port.  Each customer could be represented by a
      single-tagged VLAN, a double-tagged VLAN, a Virtual Private LAN
      Service (VPLS) instance, etc.  Each customer is mapped to a
      different policer.  Each of the policers can be of rates
      r1, r2, ..., rn.

      An example configuration would be

      -  Y1 customers, policer rate r1

      -  Y2 customers, policer rate r2

      -  Y3 customers, policer rate r3

      ...

      -  Yn customers, policer rate rn





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      Some bandwidth on the physical port is dedicated for other traffic
      (i.e., other than customer traffic); this includes network control
      protocol traffic.  There is a separate policer for the other
      traffic.  Typical deployments have three categories of policers;
      there may be some deployments with more or less than three
      categories of ingress policers.

   Procedure:
      1. Configure the DUT policing parameters for the desired CIR/EIR
         and CBS/EBS values for each policer rate (r1-rn) to be tested.

      2. Configure the tester to generate a stateless traffic burst
         equal to CBS and an interval equal to Ti (CBS in bits/CIR) for
         each customer stream (Y1-Yn).  The encapsulation for each
         customer must also be configured according to the service
         tested (VLAN, VPLS, IP mapping, etc.).

      3. Compliant Traffic Test: Generate bursts of CBS + EBS traffic
         into the policer ingress port for each customer traffic stream,
         and measure the metrics defined in Section 4.1 (BSA, LP, OOS,
         PD, and PDV) at the egress port for each stream and across the
         entire Td (default 30-second duration).

      4. Excess Traffic Test: Generate bursts of greater than CBS + EBS
         bytes into the policer ingress port for each customer traffic
         stream, and verify that the policer only allowed the BSA bytes
         to exit the egress for each stream.  The excess burst MUST be
         recorded; the recommended value is 1000 bytes.

   Reporting Format:
      The policer individual report MUST contain all results for each
      CIR/EIR/CBS/EBS test run, per customer traffic stream.  A
      recommended format is as follows:

      *****************************************************************

      Test Configuration Summary: Tr, Td

      Customer Traffic Stream Encapsulation: Map each stream to VLAN,
      VPLS, IP address

      DUT Configuration Summary per Customer Traffic Stream: CIR, EIR,
      CBS, EBS








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      The results table should contain entries for each test run,
      as follows (Test #1 to Test #Tr):

      -  Customer Stream Y1-Yn (see note) Compliant Traffic Test:
         BSA, LP, OOS, PD, and PDV

      -  Customer Stream Y1-Yn (see note) Excess Traffic Test: BSA

      *****************************************************************

      Note: For each test run, there will be two (2) rows for each
      customer stream: the Compliant Traffic Test result and the Excess
      Traffic Test result.

6.1.2.2.  Single Policer on All Physical Ports

   Test Summary:
      The second policer capacity test involves a single policer
      function per physical port with all physical ports active.  In
      this test, there is a single policer per physical port.  The
      policer can have one of the rates r1, r2, ..., rn.  All of the
      physical ports in the networking device are active.

   Procedure:
      The procedure for this test is identical to the procedure listed
      in Section 6.1.1.  The configured parameters must be reported
      per port, and the test report must include results per measured
      egress port.

6.1.2.3.  Maximum Policers on All Physical Ports

   The third policer capacity test is a combination of the first and
   second capacity tests, i.e., maximum policers active per physical
   port and all physical ports active.

   Procedure:
      The procedure for this test is identical to the procedure listed
      in Section 6.1.2.1.  The configured parameters must be reported
      per port, and the test report must include per-stream results per
      measured egress port.











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6.2.  Queue/Scheduler Tests

   Queues and traffic scheduling are closely related in that a queue's
   priority dictates the manner in which the traffic scheduler transmits
   packets out of the egress port.

   Since device queues/buffers are generally an egress function, this
   test framework will discuss testing at the egress (although the
   technique can be applied to ingress-side queues).

   Similar to the policing tests, these tests are divided into two
   sections: individual queue/scheduler function tests and then
   full-capacity tests.

6.2.1.  Queue/Scheduler Individual Tests

   The various types of scheduling techniques include FIFO, Strict
   Priority (SP) queuing, and Weighted Fair Queuing (WFQ), along with
   other variations.  This test framework recommends testing with a
   minimum of three techniques, although benchmarking other
   device-scheduling algorithms is left to the discretion of the tester.

6.2.1.1.  Testing Queue/Scheduler with Stateless Traffic

   Objective:
      Verify that the configured queue and scheduling technique can
      handle stateless traffic bursts up to the queue depth.

   Test Summary:
      A network device queue is memory based, unlike a policing
      function, which is token or credit based.  However, the same
      concepts from Section 6.1 can be applied to testing network device
      queues.

      The device's network queue should be configured to the desired
      size in KB (i.e., Queue Length (QL)), and then stateless traffic
      should be transmitted to test this QL.

      A queue should be able to handle repetitive bursts with the
      transmission gaps proportional to the Bottleneck Bandwidth (BB).
      The transmission gap is referred to here as the transmission
      interval (Ti).  The Ti can be defined for the traffic bursts and
      is based on the QL and BB of the egress interface.

         Ti = QL * 8 / BB






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      Note that this equation is similar to the Ti required for
      transmission into a policer (QL = CBS, BB = CIR).  Note also that
      the burst hunt algorithm defined in Section 5.1.1 can also be used
      to automate the measurement of the queue value.

      The stateless traffic burst SHALL be transmitted at the link speed
      and spaced within the transmission interval (Ti).  The metrics
      defined in Section 4.1 SHALL be measured at the egress port and
      recorded; the primary intent is to verify the BSA and verify that
      no packets are dropped.

      The scheduling function must also be characterized to benchmark
      the device's ability to schedule the queues according to the
      priority.  An example would be two levels of priority that include
      SP and FIFO queuing.  Under a flow load greater than the egress
      port speed, the higher-priority packets should be transmitted
      without drops (and also maintain low latency), while the lower-
      priority (or best-effort) queue may be dropped.

   Test Metrics:
      The metrics defined in Section 4.1 (BSA, LP, OOS, PD, and PDV)
      SHALL be measured at the egress port and recorded.

   Procedure:
      1. Configure the DUT QL and scheduling technique parameters (FIFO,
         SP, etc.).

      2. Configure the tester to generate a stateless traffic burst
         equal to QL and an interval equal to Ti (QL in bits/BB).

      3. Generate bursts of QL traffic into the DUT, and measure the
         metrics defined in Section 4.1 (LP, OOS, PD, and PDV) at the
         egress port and across the entire Td (default 30-second
         duration).

   Reporting Format:
      The Queue/Scheduler Stateless Traffic individual report MUST
      contain all results for each QL/BB test run.  A recommended format
      is as follows:

      ****************************************************************

      Test Configuration Summary: Tr, Td

      DUT Configuration Summary: Scheduling technique (i.e., FIFO, SP,
      WFQ, etc.), BB, and QL





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      The results table should contain entries for each test run,
      as follows (Test #1 to Test #Tr):

      -  LP, OOS, PD, and PDV

      ****************************************************************

6.2.1.2.  Testing Queue/Scheduler with Stateful Traffic

   Objective:
      Verify that the configured queue and scheduling technique can
      handle stateful traffic bursts up to the queue depth.

   Test Background and Summary:
      To provide a more realistic benchmark and to test queues in
      Layer 4 devices such as firewalls, stateful traffic testing is
      recommended for the queue tests.  Stateful traffic tests will also
      utilize the Network Delay Emulator (NDE) from the network setup
      configuration in Section 1.2.

      The BDP of the TCP test traffic must be calibrated to the QL of
      the device queue.  Referencing [RFC6349], the BDP is equal to:

         BB * RTT / 8 (in bytes)

      The NDE must be configured to an RTT value that is large enough to
      allow the BDP to be greater than QL.  An example test scenario is
      defined below:

      -  Ingress link = GigE

      -  Egress link = 100 Mbps (BB)

      -  QL = 32 KB

      RTT(min) = QL * 8 / BB and would equal 2.56 ms
         (and the BDP = 32 KB)

      In this example, one (1) TCP connection with window size / SSB of
      32 KB would be required to test the QL of 32 KB.  This Bulk
      Transfer Test can be accomplished using iperf, as described in
      Appendix A.









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      Two types of TCP tests MUST be performed: the Bulk Transfer Test
      and the Micro Burst Test Pattern, as documented in Appendix B.
      The Bulk Transfer Test only bursts during the TCP Slow Start (or
      Congestion Avoidance) state, while the Micro Burst Test Pattern
      emulates application-layer bursting, which may occur any time
      during the TCP connection.

      Other types of tests SHOULD include the following: simple web
      sites, complex web sites, business applications, email, and
      SMB/CIFS (Common Internet File System) file copy (all of which are
      also documented in Appendix B).

   Test Metrics:
      The test results will be recorded per the stateful metrics defined
      in Section 4.2 -- primarily the TCP Test Pattern Execution Time
      (TTPET), TCP Efficiency, and Buffer Delay.

   Procedure:
      1. Configure the DUT QL and scheduling technique parameters (FIFO,
         SP, etc.).

      2. Configure the test generator* with a profile of an emulated
         application traffic mixture.

         -  The application mixture MUST be defined in terms of
            percentage of the total bandwidth to be tested.

         -  The rate of transmission for each application within the
            mixture MUST also be configurable.

         *  To ensure repeatable results, the test generator MUST be
            capable of generating precise TCP test patterns for each
            application specified.

      3. Generate application traffic between the ingress (client side)
         and egress (server side) ports of the DUT, and measure the
         metrics (TTPET, TCP Efficiency, and Buffer Delay) per
         application stream and at the ingress and egress ports (across
         the entire Td, default 60-second duration).

      A couple of items require clarification concerning application
      measurements: an application session may be comprised of a single
      TCP connection or multiple TCP connections.

      If an application session utilizes a single TCP connection, the
      application throughput/metrics have a 1-1 relationship to the TCP
      connection measurements.




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      If an application session (e.g., an HTTP-based application)
      utilizes multiple TCP connections, then all of the TCP connections
      are aggregated in the application throughput measurement/metrics
      for that application.

      Then, there is the case of multiple instances of an application
      session (i.e., multiple FTPs emulating multiple clients).  In this
      situation, the test should measure/record each FTP application
      session independently, tabulating the minimum, maximum, and
      average for all FTP sessions.

      Finally, application throughput measurements are based on Layer 4
      TCP throughput and do not include bytes retransmitted.  The TCP
      Efficiency metric MUST be measured during the test, because it
      provides a measure of "goodput" during each test.

   Reporting Format:
      The Queue/Scheduler Stateful Traffic individual report MUST
      contain all results for each traffic scheduler and QL/BB test run.
      A recommended format is as follows:

      ******************************************************************

      Test Configuration Summary: Tr, Td

      DUT Configuration Summary: Scheduling technique (i.e., FIFO, SP,
      WFQ, etc.), BB, and QL

      Application Mixture and Intensities: These are the percentages
      configured for each application type.

      The results table should contain entries for each test run, with
      minimum, maximum, and average per application session, as follows
      (Test #1 to Test #Tr):

      -  Throughput (bps) and TTPET for each application session

      -  Bytes In and Bytes Out for each application session

      -  TCP Efficiency and Buffer Delay for each application session

      ******************************************************************









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6.2.2.  Queue/Scheduler Capacity Tests

   Objective:
      The intent of these capacity tests is to benchmark queue/scheduler
      performance in a scaled environment with multiple
      queues/schedulers active on multiple egress physical ports.  These
      tests will benchmark the maximum number of queues and schedulers
      as specified by the device manufacturer.  Each priority in the
      system will map to a separate queue.

   Test Metrics:
      The metrics defined in Section 4.1 (BSA, LP, OOS, PD, and PDV)
      SHALL be measured at the egress port and recorded.

   The following sections provide the specific test scenarios,
   procedures, and reporting formats for each queue/scheduler capacity
   test.

6.2.2.1.  Multiple Queues, Single Port Active

   For the first queue/scheduler capacity test, multiple queues per port
   will be tested on a single physical port.  In this case, all of the
   queues (typically eight) are active on a single physical port.
   Traffic from multiple ingress physical ports is directed to the same
   egress physical port.  This will cause oversubscription on the egress
   physical port.

   There are many types of priority schemes and combinations of
   priorities that are managed by the scheduler.  The following sections
   specify the priority schemes that should be tested.

6.2.2.1.1.  Strict Priority on Egress Port

   Test Summary:
      For this test, SP scheduling on the egress physical port should be
      tested, and the benchmarking methodologies specified in
      Sections 6.2.1.1 (stateless) and 6.2.1.2 (stateful) (procedure,
      metrics, and reporting format) should be applied here.  For a
      given priority, each ingress physical port should get a fair share
      of the egress physical-port bandwidth.











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      Since this is a capacity test, the configuration and report
      results format (see Sections 6.2.1.1 and 6.2.1.2) MUST also
      include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port

      Report Results:

      -  For each ingress port traffic stream, the achieved throughput
         rate and metrics at the egress port

6.2.2.1.2.  Strict Priority + WFQ on Egress Port

   Test Summary:
      For this test, SP and WFQ should be enabled simultaneously in the
      scheduler, but on a single egress port.  The benchmarking
      methodologies specified in Sections 6.2.1.1 (stateless) and
      6.2.1.2 (stateful) (procedure, metrics, and reporting format)
      should be applied here.  Additionally, the egress port
      bandwidth-sharing among weighted queues should be proportional to
      the assigned weights.  For a given priority, each ingress physical
      port should get a fair share of the egress physical-port
      bandwidth.

      Since this is a capacity test, the configuration and report
      results format (see Sections 6.2.1.1 and 6.2.1.2) MUST also
      include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port




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      Report Results:

      -  For each ingress port traffic stream, the achieved throughput
         rate and metrics at each queue of the egress port queue (both
         the SP and WFQ)

      Example:

      -  Egress Port SP Queue: throughput and metrics for ingress
         streams 1-n

      -  Egress Port WFQ: throughput and metrics for ingress streams 1-n

6.2.2.2.  Single Queue per Port, All Ports Active

   Test Summary:
      Traffic from multiple ingress physical ports is directed to the
      same egress physical port.  This will cause oversubscription on
      the egress physical port.  Also, the same amount of traffic is
      directed to each egress physical port.

      The benchmarking methodologies specified in Sections 6.2.1.1
      (stateless) and 6.2.1.2 (stateful) (procedure, metrics, and
      reporting format)  should be applied here.  Each ingress physical
      port should get a fair share of the egress physical-port
      bandwidth.  Additionally, each egress physical port should receive
      the same amount of traffic.

      Since this is a capacity test, the configuration and report
      results format (see Sections 6.2.1.1 and 6.2.1.2) MUST also
      include:

      Configuration:

      -  The number of ingress ports active during the test

      -  The number of egress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port







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      Report Results:

      -  For each egress port, the achieved throughput rate and metrics
         at the egress port queue for each ingress port stream

      Example:

      -  Egress Port 1: throughput and metrics for ingress streams 1-n

      -  Egress Port n: throughput and metrics for ingress streams 1-n

6.2.2.3.  Multiple Queues per Port, All Ports Active

   Test Summary:
      Traffic from multiple ingress physical ports is directed to all
      queues of each egress physical port.  This will cause
      oversubscription on the egress physical ports.  Also, the same
      amount of traffic is directed to each egress physical port.

      The benchmarking methodologies specified in Sections 6.2.1.1
      (stateless) and 6.2.1.2 (stateful) (procedure, metrics, and
      reporting format) should be applied here.  For a given priority,
      each ingress physical port should get a fair share of the egress
      physical-port bandwidth.  Additionally, each egress physical port
      should receive the same amount of traffic.

      Since this is a capacity test, the configuration and report
      results format (see Sections 6.2.1.1 and 6.2.1.2) MUST also
      include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port

      Report Results:

      -  For each egress port, the achieved throughput rate and metrics
         at each egress port queue for each ingress port stream






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      Example:

      -  Egress Port 1, SP Queue: throughput and metrics for ingress
         streams 1-n

      -  Egress Port 2, WFQ: throughput and metrics for ingress
         streams 1-n

      ...

      -  Egress Port n, SP Queue: throughput and metrics for ingress
         streams 1-n

      -  Egress Port n, WFQ: throughput and metrics for ingress
         streams 1-n

6.3.  Shaper Tests

   Like a queue, a traffic shaper is memory based, but with the added
   intelligence of an active traffic scheduler.  The same concepts as
   those described in Section 6.2 (queue testing) can be applied to
   testing a network device shaper.

   Again, the tests are divided into two sections: individual shaper
   benchmark tests and then full-capacity shaper benchmark tests.

6.3.1.  Shaper Individual Tests

   A traffic shaper generally has three (3) components that can be
   configured:

   -  Ingress Queue bytes

   -  Shaper Rate (SR), bps

   -  Burst Committed (Bc) and Burst Excess (Be), bytes

   The Ingress Queue holds burst traffic, and the shaper then meters
   traffic out of the egress port according to the SR and Bc/Be
   parameters.  Shapers generally transmit into policers, so the idea is
   for the emitted traffic to conform to the policer's limits.










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6.3.1.1.  Testing Shaper with Stateless Traffic

   Objective:
      Test a shaper by transmitting stateless traffic bursts into the
      shaper ingress port and verifying that the egress traffic is
      shaped according to the shaper traffic profile.

   Test Summary:
      The stateless traffic must be burst into the DUT ingress port and
      not exceed the Ingress Queue.  The burst can be a single burst or
      multiple bursts.  If multiple bursts are transmitted, then the
      transmission interval (Ti) must be large enough so that the SR is
      not exceeded.  An example will clarify single-burst and multiple-
      burst test cases.

      In this example, the shaper's ingress and egress ports are both
      full-duplex Gigabit Ethernet.  The Ingress Queue is configured to
      be 512,000 bytes, the SR = 50 Mbps, and both Bc and Be are
      configured to be 32,000 bytes.  For a single-burst test, the
      transmitting test device would burst 512,000 bytes maximum into
      the ingress port and then stop transmitting.

      If a multiple-burst test is to be conducted, then the burst bytes
      divided by the transmission interval between the 512,000-byte
      bursts must not exceed the SR.  The transmission interval (Ti)
      must adhere to a formula similar to the formula described in
      Section 6.2.1.1 for queues, namely:

         Ti = Ingress Queue * 8 / SR

      For the example from the previous paragraph, the Ti between bursts
      must be greater than 82 milliseconds (512,000 bytes * 8 /
      50,000,000 bps).  This yields an average rate of 50 Mbps so that
      an Ingress Queue would not overflow.

   Test Metrics:
      The metrics defined in Section 4.1 (LP, OOS, PDV, SR, SBB, and
      SBI) SHALL be measured at the egress port and recorded.

   Procedure:
      1. Configure the DUT shaper ingress QL and shaper egress rate
         parameters (SR, Bc, Be).

      2. Configure the tester to generate a stateless traffic burst
         equal to QL and an interval equal to Ti (QL in bits/BB).






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      3. Generate bursts of QL traffic into the DUT, and measure the
         metrics defined in Section 4.1 (LP, OOS, PDV, SR, SBB, and SBI)
         at the egress port and across the entire Td (default 30-second
         duration).

   Reporting Format:
      The Shaper Stateless Traffic individual report MUST contain all
      results for each QL/SR test run.  A recommended format is as
      follows:

      ***********************************************************

      Test Configuration Summary: Tr, Td

      DUT Configuration Summary: Ingress Burst Rate, QL, SR

      The results table should contain entries for each test run,
      as follows (Test #1 to Test #Tr):

      -  LP, OOS, PDV, SR, SBB, and SBI

      ***********************************************************

6.3.1.2.  Testing Shaper with Stateful Traffic

   Objective:
      Test a shaper by transmitting stateful traffic bursts into the
      shaper ingress port and verifying that the egress traffic is
      shaped according to the shaper traffic profile.

   Test Summary:
      To provide a more realistic benchmark and to test queues in
      Layer 4 devices such as firewalls, stateful traffic testing is
      also recommended for the shaper tests.  Stateful traffic tests
      will also utilize the Network Delay Emulator (NDE) from the
      network setup configuration in Section 1.2.

      The BDP of the TCP test traffic must be calculated as described in
      Section 6.2.1.2.  To properly stress network buffers and the
      traffic-shaping function, the TCP window size (which is the
      minimum of the TCP RWND and sender socket) should be greater than
      the BDP, which will stress the shaper.  BDP factors of 1.1 to 1.5
      are recommended, but the values are left to the discretion of the
      tester and should be documented.







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      The cumulative TCP window sizes* (RWND at the receiving end and
      CWND at the transmitting end) equates to the TCP window size* for
      each connection, multiplied by the number of connections.

      *  As described in Section 3 of [RFC6349], the SSB MUST be large
         enough to fill the BDP.

      For example, if the BDP is equal to 256 KB and a connection size
      of 64 KB is used for each connection, then it would require four
      (4) connections to fill the BDP and 5-6 connections (oversubscribe
      the BDP) to stress-test the traffic-shaping function.

      Two types of TCP tests MUST be performed: the Bulk Transfer Test
      and the Micro Burst Test Pattern, as documented in Appendix B.
      The Bulk Transfer Test only bursts during the TCP Slow Start (or
      Congestion Avoidance) state, while the Micro Burst Test Pattern
      emulates application-layer bursting, which may occur any time
      during the TCP connection.

      Other types of tests SHOULD include the following: simple web
      sites, complex web sites, business applications, email, and
      SMB/CIFS file copy (all of which are also documented in
      Appendix B).

   Test Metrics:
      The test results will be recorded per the stateful metrics defined
      in Section 4.2 -- primarily the TCP Test Pattern Execution Time
      (TTPET), TCP Efficiency, and Buffer Delay.

   Procedure:
      1. Configure the DUT shaper ingress QL and shaper egress rate
         parameters (SR, Bc, Be).

      2. Configure the test generator* with a profile of an emulated
         application traffic mixture.

         -  The application mixture MUST be defined in terms of
            percentage of the total bandwidth to be tested.

         -  The rate of transmission for each application within the
            mixture MUST also be configurable.

         *  To ensure repeatable results, the test generator MUST be
            capable of generating precise TCP test patterns for each
            application specified.






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      3. Generate application traffic between the ingress (client side)
         and egress (server side) ports of the DUT, and measure the
         metrics (TTPET, TCP Efficiency, and Buffer Delay) per
         application stream and at the ingress and egress ports (across
         the entire Td, default 30-second duration).

   Reporting Format:
      The Shaper Stateful Traffic individual report MUST contain all
      results for each traffic scheduler and QL/SR test run.  A
      recommended format is as follows:

      ******************************************************************

      Test Configuration Summary: Tr, Td

      DUT Configuration Summary: Ingress Burst Rate, QL, SR

      Application Mixture and Intensities: These are the percentages
      configured for each application type.

      The results table should contain entries for each test run, with
      minimum, maximum, and average per application session, as follows
      (Test #1 to Test #Tr):

      -  Throughput (bps) and TTPET for each application session

      -  Bytes In and Bytes Out for each application session

      -  TCP Efficiency and Buffer Delay for each application session

      ******************************************************************

6.3.2.  Shaper Capacity Tests

   Objective:
      The intent of these scalability tests is to verify shaper
      performance in a scaled environment with shapers active on
      multiple queues on multiple egress physical ports.  These tests
      will benchmark the maximum number of shapers as specified by the
      device manufacturer.

   The following sections provide the specific test scenarios,
   procedures, and reporting formats for each shaper capacity test.








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6.3.2.1.  Single Queue Shaped, All Physical Ports Active

   Test Summary:
      The first shaper capacity test involves per-port shaping with all
      physical ports active.  Traffic from multiple ingress physical
      ports is directed to the same egress physical port.  This will
      cause oversubscription on the egress physical port.  Also, the
      same amount of traffic is directed to each egress physical port.

      The benchmarking methodologies specified in Sections 6.3.1.1
      (stateless) and 6.3.1.2 (stateful) (procedure, metrics, and
      reporting format) should be applied here.  Since this is a
      capacity test, the configuration and report results format (see
      Section 6.3.1) MUST also include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port

      -  The shaped egress port shaper parameters (QL, SR, Bc, Be)

      Report Results:

      -  For each active egress port, the achieved throughput rate and
         shaper metrics for each ingress port traffic stream

      Example:

      -  Egress Port 1: throughput and metrics for ingress streams 1-n

      -  Egress Port n: throughput and metrics for ingress streams 1-n

6.3.2.2.  All Queues Shaped, Single Port Active

   Test Summary:
      The second shaper capacity test is conducted with all queues
      actively shaping on a single physical port.  The benchmarking
      methodology described in the per-port shaping test
      (Section 6.3.2.1) serves as the foundation for this.
      Additionally, each of the SP queues on the egress physical port is
      configured with a shaper.  For the highest-priority queue, the



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      maximum amount of bandwidth available is limited by the bandwidth
      of the shaper.  For the lower-priority queues, the maximum amount
      of bandwidth available is limited by the bandwidth of the shaper
      and traffic in higher-priority queues.

      The benchmarking methodologies specified in Sections 6.3.1.1
      (stateless) and 6.3.1.2 (stateful) (procedure, metrics, and
      reporting format) should be applied here.  Since this is a
      capacity test, the configuration and report results format (see
      Section 6.3.1) MUST also include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port

      -  For the active egress port, each of the following shaper queue
         parameters: QL, SR, Bc, Be

      Report Results:

      -  For each queue of the active egress port, the achieved
         throughput rate and shaper metrics for each ingress port
         traffic stream

      Example:

      -  Egress Port High-Priority Queue: throughput and metrics for
         ingress streams 1-n

      -  Egress Port Lower-Priority Queue: throughput and metrics for
         ingress streams 1-n













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6.3.2.3.  All Queues Shaped, All Ports Active

   Test Summary:
      For the third shaper capacity test (which is a combination of the
      tests listed in Sections 6.3.2.1 and 6.3.2.2), all queues will be
      actively shaping and all physical ports active.

      The benchmarking methodologies specified in Sections 6.3.1.1
      (stateless) and 6.3.1.2 (stateful) (procedure, metrics, and
      reporting format) should be applied here.  Since this is a
      capacity test, the configuration and report results format (see
      Section 6.3.1) MUST also include:

      Configuration:

      -  The number of physical ingress ports active during the test

      -  The classification marking (DSCP, VLAN, etc.) for each physical
         ingress port

      -  The traffic rate for stateful traffic and the traffic
         rate/mixture for stateful traffic for each physical
         ingress port

      -  For each of the active egress ports: shaper port parameters and
         per-queue parameters (QL, SR, Bc, Be)

      Report Results:

      -  For each queue of each active egress port, the achieved
         throughput rate and shaper metrics for each ingress port
         traffic stream

      Example:

      -  Egress Port 1, High-Priority Queue: throughput and metrics for
         ingress streams 1-n

      -  Egress Port 1, Lower-Priority Queue: throughput and metrics for
         ingress streams 1-n

      ...

      -  Egress Port n, High-Priority Queue: throughput and metrics for
         ingress streams 1-n

      -  Egress Port n, Lower-Priority Queue: throughput and metrics for
         ingress streams 1-n



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6.4.  Concurrent Capacity Load Tests

   As mentioned in Section 3 of this document, it is impossible to
   specify the various permutations of concurrent traffic management
   functions that should be tested in a device for capacity testing.
   However, some profiles are listed below that may be useful for
   testing multiple configurations of traffic management functions:

   -  Policers on ingress and queuing on egress

   -  Policers on ingress and shapers on egress (not intended for a flow
      to be policed and then shaped; these would be two different flows
      tested at the same time)

   The test procedures and reporting formats from Sections 6.1, 6.2,
   and 6.3 may be modified to accommodate the capacity test profile.

7.  Security Considerations

   Documents of this type do not directly affect the security of the
   Internet or of corporate networks as long as benchmarking is not
   performed on devices or systems connected to production networks.

   Further, benchmarking is performed on a "black box" basis, relying
   solely on measurements observable external to the DUT/SUT.

   Special capabilities SHOULD NOT exist in the DUT/SUT specifically for
   benchmarking purposes.  Any implications for network security arising
   from the DUT/SUT SHOULD be identical in the lab and in production
   networks.





















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8.  References

8.1.  Normative References

   [3GPP2-C_R1002-A]
              3rd Generation Partnership Project 2, "cdma2000 Evaluation
              Methodology", Version 1.0, Revision A, May 2009,
              <http://www.3gpp2.org/public_html/specs/
              C.R1002-A_v1.0_Evaluation_Methodology.pdf>.

   [RFC1242]  Bradner, S., "Benchmarking Terminology for Network
              Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242,
              July 1991, <http://www.rfc-editor.org/info/rfc1242>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2544]  Bradner, S. and J. McQuaid, "Benchmarking Methodology for
              Network Interconnect Devices", RFC 2544,
              DOI 10.17487/RFC2544, March 1999,
              <http://www.rfc-editor.org/info/rfc2544>.

   [RFC2680]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Packet Loss Metric for IPPM", RFC 2680,
              DOI 10.17487/RFC2680, September 1999,
              <http://www.rfc-editor.org/info/rfc2680>.

   [RFC3148]  Mathis, M. and M. Allman, "A Framework for Defining
              Empirical Bulk Transfer Capacity Metrics", RFC 3148,
              DOI 10.17487/RFC3148, July 2001,
              <http://www.rfc-editor.org/info/rfc3148>.

   [RFC4115]  Aboul-Magd, O. and S. Rabie, "A Differentiated Service
              Two-Rate, Three-Color Marker with Efficient Handling of
              in-Profile Traffic", RFC 4115, DOI 10.17487/RFC4115,
              July 2005, <http://www.rfc-editor.org/info/rfc4115>.

   [RFC4689]  Poretsky, S., Perser, J., Erramilli, S., and S. Khurana,
              "Terminology for Benchmarking Network-layer Traffic
              Control Mechanisms", RFC 4689, DOI 10.17487/RFC4689,
              October 2006, <http://www.rfc-editor.org/info/rfc4689>.

   [RFC4737]  Morton, A., Ciavattone, L., Ramachandran, G., Shalunov,
              S., and J. Perser, "Packet Reordering Metrics", RFC 4737,
              DOI 10.17487/RFC4737, November 2006,
              <http://www.rfc-editor.org/info/rfc4737>.



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   [RFC5481]  Morton, A. and B. Claise, "Packet Delay Variation
              Applicability Statement", RFC 5481, DOI 10.17487/RFC5481,
              March 2009, <http://www.rfc-editor.org/info/rfc5481>.

   [RFC6349]  Constantine, B., Forget, G., Geib, R., and R. Schrage,
              "Framework for TCP Throughput Testing", RFC 6349,
              DOI 10.17487/RFC6349, August 2011,
              <http://www.rfc-editor.org/info/rfc6349>.

   [RFC6703]  Morton, A., Ramachandran, G., and G. Maguluri, "Reporting
              IP Network Performance Metrics: Different Points of View",
              RFC 6703, DOI 10.17487/RFC6703, August 2012,
              <http://www.rfc-editor.org/info/rfc6703>.

   [SPECweb2009]
              Standard Performance Evaluation Corporation (SPEC),
              "SPECweb2009 Release 1.20 Benchmark Design Document",
              April 2010, <https://www.spec.org/web2009/docs/design/
              SPECweb2009_Design.html>.

8.2.  Informative References

   [CA-Benchmark]
              Hamilton, M. and S. Banks, "Benchmarking Methodology for
              Content-Aware Network Devices", Work in Progress,
              draft-ietf-bmwg-ca-bench-meth-04, February 2013.

   [CoDel]    Nichols, K., Jacobson, V., McGregor, A., and J. Iyengar,
              "Controlled Delay Active Queue Management", Work in
              Progress, draft-ietf-aqm-codel-01, April 2015.

   [MEF-10.3] Metro Ethernet Forum, "Ethernet Services Attributes
              Phase 3", MEF 10.3, October 2013,
              <https://www.mef.net/Assets/Technical_Specifications/
              PDF/MEF_10.3.pdf>.

   [MEF-12.2] Metro Ethernet Forum, "Carrier Ethernet Network
              Architecture Framework -- Part 2: Ethernet Services
              Layer", MEF 12.2, May 2014,
              <https://www.mef.net/Assets/Technical_Specifications/
              PDF/MEF_12.2.pdf>.

   [MEF-14]   Metro Ethernet Forum, "Abstract Test Suite for Traffic
              Management Phase 1", MEF 14, November 2005,
              <https://www.mef.net/Assets/
              Technical_Specifications/PDF/MEF_14.pdf>.





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   [MEF-19]   Metro Ethernet Forum, "Abstract Test Suite for UNI
              Type 1", MEF 19, April 2007, <https://www.mef.net/Assets/
              Technical_Specifications/PDF/MEF_19.pdf>.

   [MEF-26.1] Metro Ethernet Forum, "External Network Network Interface
              (ENNI) - Phase 2", MEF 26.1, January 2012,
              <http://www.mef.net/Assets/Technical_Specifications/
              PDF/MEF_26.1.pdf>.

   [MEF-37]   Metro Ethernet Forum, "Abstract Test Suite for ENNI",
              MEF 37, January 2012, <https://www.mef.net/Assets/
              Technical_Specifications/PDF/MEF_37.pdf>.

   [PIE]      Pan, R., Natarajan, P., Baker, F., White, G., VerSteeg,
              B., Prabhu, M., Piglione, C., and V. Subramanian, "PIE: A
              Lightweight Control Scheme To Address the Bufferbloat
              Problem", Work in Progress, draft-ietf-aqm-pie-02,
              August 2015.

   [RFC2697]  Heinanen, J. and R. Guerin, "A Single Rate Three Color
              Marker", RFC 2697, DOI 10.17487/RFC2697, September 1999,
              <http://www.rfc-editor.org/info/rfc2697>.

   [RFC2698]  Heinanen, J. and R. Guerin, "A Two Rate Three Color
              Marker", RFC 2698, DOI 10.17487/RFC2698, September 1999,
              <http://www.rfc-editor.org/info/rfc2698>.

   [RFC7567]  Baker, F., Ed., and G. Fairhurst, Ed., "IETF
              Recommendations Regarding Active Queue Management",
              BCP 197, RFC 7567, DOI 10.17487/RFC7567, July 2015,
              <http://www.rfc-editor.org/info/rfc7567>.




















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Appendix A.  Open Source Tools for Traffic Management Testing

   This framework specifies that stateless and stateful behaviors SHOULD
   both be tested.  Some open source tools that can be used to
   accomplish many of the tests proposed in this framework are iperf,
   netperf (with netperf-wrapper), the "uperf" tool, Tmix,
   TCP-incast-generator, and D-ITG (Distributed Internet Traffic
   Generator).

   iperf can generate UDP-based or TCP-based traffic; a client and
   server must both run the iperf software in the same traffic mode.
   The server is set up to listen, and then the test traffic is
   controlled from the client.  Both unidirectional and bidirectional
   concurrent testing are supported.

   The UDP mode can be used for the stateless traffic testing.  The
   target bandwidth, packet size, UDP port, and test duration can be
   controlled.  A report of bytes transmitted, packets lost, and delay
   variation is provided by the iperf receiver.

   iperf (TCP mode), TCP-incast-generator, and D-ITG can be used for
   stateful traffic testing to test bulk transfer traffic.  The TCP
   window size (which is actually the SSB), number of connections,
   packet size, TCP port, and test duration can be controlled.  A report
   of bytes transmitted and throughput achieved is provided by the iperf
   sender, while TCP-incast-generator and D-ITG provide even more
   statistics.

   netperf is a software application that provides network bandwidth
   testing between two hosts on a network.  It supports UNIX domain
   sockets, TCP, SCTP, and UDP via BSD Sockets.  netperf provides a
   number of predefined tests, e.g., to measure bulk (unidirectional)
   data transfer or request/response performance
   (http://en.wikipedia.org/wiki/Netperf).  netperf-wrapper is a Python
   script that runs multiple simultaneous netperf instances and
   aggregates the results.

   uperf uses a description (or model) of an application mixture.  It
   generates the load according to the model descriptor.  uperf is more
   flexible than netperf in its ability to generate request/response
   application behavior within a single TCP connection.  The application
   model descriptor can be based on empirical data, but at the time of
   this writing, the import of packet captures is not directly
   supported.







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   Tmix is another application traffic emulation tool.  It uses packet
   captures directly to create the traffic profile.  The packet trace is
   "reverse compiled" into a source-level characterization, called a
   "connection vector", of each TCP connection present in the trace.
   While most widely used in ns2 simulation environments, Tmix also runs
   on Linux hosts.

   The traffic generation capabilities of these open source tools
   facilitate the emulation of the TCP test patterns discussed in
   Appendix B.

Appendix B.  Stateful TCP Test Patterns

   This framework recommends at a minimum the following TCP test
   patterns, since they are representative of real-world application
   traffic (Section 5.2.1 describes some methods to derive other
   application-based TCP test patterns).

   -  Bulk Transfer: Generate concurrent TCP connections whose aggregate
      number of in-flight data bytes would fill the BDP.  Guidelines
      from [RFC6349] are used to create this TCP traffic pattern.

   -  Micro Burst: Generate precise burst patterns within a single TCP
      connection or multiple TCP connections.  The idea is for TCP to
      establish equilibrium and then burst application bytes at defined
      sizes.  The test tool must allow the burst size and burst time
      interval to be configurable.

   -  Web Site Patterns: The HTTP traffic model shown in Table 4.1.3-1
      of [3GPP2-C_R1002-A] demonstrates a way to develop these TCP test
      patterns.  In summary, the HTTP traffic model consists of the
      following parameters:

      -  Main object size (Sm)

      -  Embedded object size (Se)

      -  Number of embedded objects per page (Nd)

      -  Client processing time (Tcp)

      -  Server processing time (Tsp)









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   Web site test patterns are illustrated with the following examples:

   -  Simple web site: Mimic the request/response and object download
      behavior of a basic web site (small company).

   -  Complex web site: Mimic the request/response and object download
      behavior of a complex web site (eCommerce site).

   Referencing the HTTP traffic model parameters, the following table
   was derived (by analysis and experimentation) for simple web site and
   complex web site TCP test patterns:

                             Simple         Complex
    Parameter                Web Site       Web Site
    -----------------------------------------------------
    Main object              Ave. = 10KB    Ave. = 300KB
     size (Sm)               Min. = 100B    Min. = 50KB
                             Max. = 500KB   Max. = 2MB

    Embedded object          Ave. = 7KB     Ave. = 10KB
     size (Se)               Min. = 50B     Min. = 100B
                             Max. = 350KB   Max. = 1MB

    Number of embedded       Ave. = 5       Ave. = 25
     objects per page (Nd)   Min. = 2       Min. = 10
                             Max. = 10      Max. = 50

    Client processing        Ave. = 3s      Ave. = 10s
     time (Tcp)*             Min. = 1s      Min. = 3s
                             Max. = 10s     Max. = 30s

    Server processing        Ave. = 5s      Ave. = 8s
     time (Tsp)*             Min. = 1s      Min. = 2s
                             Max. = 15s     Max. = 30s

   *  The client and server processing time is distributed across the
      transmission/receipt of all of the main and embedded objects.

   To be clear, the parameters in this table are reasonable guidelines
   for the TCP test pattern traffic generation.  The test tool can use
   fixed parameters for simpler tests and mathematical distributions for
   more complex tests.  However, the test pattern must be repeatable to
   ensure that the benchmark results can be reliably compared.








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   -  Interactive Patterns: While web site patterns are interactive to a
      degree, they mainly emulate the downloading of web sites of
      varying complexity.  Interactive patterns are more chatty in
      nature, since there is a lot of user interaction with the servers.
      Examples include business applications such as PeopleSoft and
      Oracle, and consumer applications such as Facebook and IM.  For
      the interactive patterns, the packet capture technique was used to
      characterize some business applications and also the email
      application.

   In summary, an interactive application can be described by the
   following parameters:

   -  Client message size (Scm)

   -  Number of client messages (Nc)

   -  Server response size (Srs)

   -  Number of server messages (Ns)

   -  Client processing time (Tcp)

   -  Server processing time (Tsp)

   -  File size upload (Su)*

   -  File size download (Sd)*

   *  The file size parameters account for attachments uploaded or
      downloaded and may not be present in all interactive applications.




















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   Again using packet capture as a means to characterize, the following
   table reflects the guidelines for simple business applications,
   complex business applications, eCommerce, and email Send/Receive:

                     Simple       Complex
                     Business     Business
   Parameter         Application  Application  eCommerce*   Email
   --------------------------------------------------------------------
   Client message    Ave. = 450B  Ave. = 2KB   Ave. = 1KB   Ave. = 200B
    size (Scm)       Min. = 100B  Min. = 500B  Min. = 100B  Min. = 100B
                     Max. = 1.5KB Max. = 100KB Max. = 50KB  Max. = 1KB

   Number of client  Ave. = 10    Ave. = 100   Ave. = 20    Ave. = 10
    messages (Nc)    Min. = 5     Min. = 50    Min. = 10    Min. = 5
                     Max. = 25    Max. = 250   Max. = 100   Max. = 25

   Client processing Ave. = 10s   Ave. = 30s   Ave. = 15s   Ave. = 5s
    time (Tcp)**     Min. = 3s    Min. = 3s    Min. = 5s    Min. = 3s
                     Max. = 30s   Max. = 60s   Max. = 120s  Max. = 45s

   Server response   Ave. = 2KB   Ave. = 5KB   Ave. = 8KB   Ave. = 200B
    size (Srs)       Min. = 500B  Min. = 1KB   Min. = 100B  Min. = 150B
                     Max. = 100KB Max. = 1MB   Max. = 50KB  Max. = 750B

   Number of server  Ave. = 50    Ave. = 200   Ave. = 100   Ave. = 15
    messages (Ns)    Min. = 10    Min. = 25    Min. = 15    Min. = 5
                     Max. = 200   Max. = 1000  Max. = 500   Max. = 40

   Server processing Ave. = 0.5s  Ave. = 1s    Ave. = 2s    Ave. = 4s
    time (Tsp)**     Min. = 0.1s  Min. = 0.5s  Min. = 1s    Min. = 0.5s
                     Max. = 5s    Max. = 20s   Max. = 10s   Max. = 15s

   File size         Ave. = 50KB  Ave. = 100KB Ave. = N/A   Ave. = 100KB
    upload (Su)      Min. = 2KB   Min. = 10KB  Min. = N/A   Min. = 20KB
                     Max. = 200KB Max. = 2MB   Max. = N/A   Max. = 10MB

   File size         Ave. = 50KB  Ave. = 100KB Ave. = N/A   Ave. = 100KB
    download (Sd)    Min. = 2KB   Min. = 10KB  Min. = N/A   Min. = 20KB
                     Max. = 200KB Max. = 2MB   Max. = N/A   Max. = 10MB

   *  eCommerce used a combination of packet capture techniques and
      reference traffic flows as described in [SPECweb2009].

   ** The client and server processing time is distributed across the
      transmission/receipt of all of the messages.  The client
      processing time consists mainly of the delay between user
      interactions (not machine processing).




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   Again, the parameters in this table are the guidelines for the TCP
   test pattern traffic generation.  The test tool can use fixed
   parameters for simpler tests and mathematical distributions for more
   complex tests.  However, the test pattern must be repeatable to
   ensure that the benchmark results can be reliably compared.

   -  SMB/CIFS file copy: Mimic a network file copy, both read and
      write.  As opposed to FTP, which is a bulk transfer and is only
      flow-controlled via TCP, SMB/CIFS divides a file into application
      blocks and utilizes application-level handshaking in addition to
      TCP flow control.

   In summary, an SMB/CIFS file copy can be described by the following
   parameters:

   -  Client message size (Scm)

   -  Number of client messages (Nc)

   -  Server response size (Srs)

   -  Number of server messages (Ns)

   -  Client processing time (Tcp)

   -  Server processing time (Tsp)

   -  Block size (Sb)

   The client and server messages are SMB control messages.  The block
   size is the data portion of the file transfer.




















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   Again using packet capture as a means to characterize, the following
   table reflects the guidelines for SMB/CIFS file copy:

                          SMB/CIFS
      Parameter           File Copy
      --------------------------------
      Client message      Ave. = 450B
       size (Scm)         Min. = 100B
                          Max. = 1.5KB

      Number of client    Ave. = 10
       messages (Nc)      Min. = 5
                          Max. = 25

      Client processing   Ave. = 1ms
       time (Tcp)         Min. = 0.5ms
                          Max. = 2

      Server response     Ave. = 2KB
       size (Srs)         Min. = 500B
                          Max. = 100KB

      Number of server    Ave. = 10
       messages (Ns)      Min. = 10
                          Max. = 200

      Server processing   Ave. = 1ms
       time (Tsp)         Min. = 0.5ms
                          Max. = 2ms

      Block               Ave. = N/A
       size (Sb)*         Min. = 16KB
                          Max. = 128KB

      *  Depending upon the tested file size, the block size will be
         transferred "n" number of times to complete the example.  An
         example would be a 10 MB file test and 64 KB block size.  In
         this case, 160 blocks would be transferred after the control
         channel is opened between the client and server.












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Acknowledgments

   We would like to thank Al Morton for his continuous review and
   invaluable input to this document.  We would also like to thank Scott
   Bradner for providing guidance early in this document's conception,
   in the area of the benchmarking scope of traffic management
   functions.  Additionally, we would like to thank Tim Copley for his
   original input, as well as David Taht, Gory Erg, and Toke
   Hoiland-Jorgensen for their review and input for the AQM group.
   Also, for the formal reviews of this document, we would like to thank
   Gilles Forget, Vijay Gurbani, Reinhard Schrage, and Bhuvaneswaran
   Vengainathan.

Authors' Addresses

   Barry Constantine
   JDSU, Test and Measurement Division
   Germantown, MD  20876-7100
   United States

   Phone: +1-240-404-2227
   Email: barry.constantine@jdsu.com


   Ram (Ramki) Krishnan
   Dell Inc.
   Santa Clara, CA  95054
   United States

   Phone: +1-408-406-7890
   Email: ramkri123@gmail.com




















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