Internet DRAFT - draft-constantine-bmwg-traffic-management
draft-constantine-bmwg-traffic-management
Network Working Group B. Constantine
Internet Draft JDSU
Intended status: Informational T. Copley
Expires: December 2014 Level-3
June 25, 2014 R. Krishnan
Brocade Communications
Traffic Management Benchmarking
draft-constantine-bmwg-traffic-management-04.txt
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Abstract
This framework describes a practical methodology for benchmarking the
traffic management capabilities of networking devices (i.e. policing,
shaping, etc.). The goal is 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.
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Table of Contents
1. Introduction...................................................4
1.1. Traffic Management Overview...............................4
1.2. DUT Lab Configuration and Testing Overview................5
2. Conventions used in this document..............................7
3. Scope and Goals................................................8
4. Traffic Benchmarking Metrics...................................9
4.1. Metrics for Stateless Traffic Tests.......................9
4.2. Metrics for Stateful Traffic Tests.......................11
5. Tester Capabilities...........................................11
5.1. Stateless Test Traffic Generation........................11
5.2. Stateful Test Pattern Generation.........................12
5.2.1. TCP Test Pattern Definitions........................13
6. Traffic Benchmarking Methodology..............................15
6.1. Policing Tests...........................................15
6.1.1 Policer Individual Tests................................15
6.1.2 Policer Capacity Tests..............................16
6.1.2.1 Maximum Policers on Single Physical Port..........16
6.1.2.2 Single Policer on All Physical Ports..............17
6.1.2.3 Maximum Policers on All Physical Ports............17
6.2. Queue/Scheduler Tests....................................17
6.2.1 Queue/Scheduler Individual Tests........................17
6.2.1.1 Testing Queue/Scheduler with Stateless Traffic....17
6.2.1.2 Testing Queue/Scheduler with Stateful Traffic.....18
6.2.2 Queue / Scheduler Capacity Tests......................19
6.2.2.1 Multiple Queues / Single Port Active..............19
6.2.2.1.1 Strict Priority on Egress Port..................19
6.2.2.1.2 Strict Priority + Weighted Fair Queue (WFQ).....19
6.2.2.2 Single Queue per Port / All Ports Active..........19
6.2.2.3 Multiple Queues per Port, All Ports Active........20
6.3. Shaper tests.............................................20
6.3.1 Shaper Individual Tests...............................20
6.3.1.1 Testing Shaper with Stateless Traffic.............20
6.3.1.2 Testing Shaper with Stateful Traffic..............21
6.3.2 Shaper Capacity Tests.................................22
6.3.2.1 Single Queue Shaped, All Physical Ports Active....22
6.3.2.2 All Queues Shaped, Single Port Active.............22
6.3.2.3 All Queues Shaped, All Ports Active...............22
6.4. Concurrent Capacity Load Tests...........................24
7. Security Considerations.......................................24
8. IANA Considerations...........................................24
9. Conclusions...................................................24
10. References...................................................24
10.1. Normative References....................................25
10.2. Informative References..................................25
11. Acknowledgments..............................................25
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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. This draft 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 benchmarking, Layer 4 test
patterns are proposed by this draft 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 (i.e. VLAN, DSCP, etc.) 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 contracted limits, the traffic is either dropped or
remarked and sent onto to the next network device
- 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: a traffic control technique that actively buffers
and meters the output rate in an attempt to adapt bursty traffic
to the configured limits
- Active Queue Management (AQM): monitors the status of internal
queues and actively drops (or re-marks) packets, which causes hosts
using congestion-aware protocols to back-off and in turn can
alleviate queue congestion. Note that AQM is outside of the scope
of this testing framework.
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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 provide context to this test framework.
|----------| |----------------| |--------------| |----------|
| | | | | | | |
|Interface | |Ingress Actions | |Egress Actions| |Interface |
|Input | |(classification,| |(scheduling, | |Output |
|Queues | | marking, | | shaping, | |Queues |
| |-->| policing or |-->| active queue |-->| |
| | | shaping) | | management | | |
| | | | | re-marking) | | |
|----------| |----------------| |--------------| |----------|
Figure 1: Generic Traffic Management capabilities of a Network Device
Ingress actions such as classification are defined in RFC 4689 and
include IP addresses, port numbers, DSCP, etc. In terms of marking,
RFC 2697 and RFC 2698 define a single rate and dual rate, three color
marker, respectively.
The MEF specifies policing and shaping in terms of Ingress and Egress
Subscriber/Provider Conditioning Functions in MEF12.1; Ingress and
Bandwidth Profile attributes in MEF 10.2 and MEF 26.
1.2 DUT Lab Configuration and Testing Overview
The following is the description of the lab set-up for the traffic
management tests:
+--------------+ +-------+ +----------+ +-----------+
| Transmitting | | | | | | Receiving |
| Test Host | | | | | | Test Host |
| |-----| DUT |---->| Network |--->| |
| | | | | Delay | | |
| | | | | Emulator | | |
| |<----| |<----| |<---| |
| | | | | | | |
+--------------+ +-------+ +----------+ +-----------+
As shown in the test diagram, the framework supports uni-directional
and bi-directional traffic management tests.
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This testing framework describes the tests and metrics for each of
the following traffic management functions:
- Policing
- Queuing / Scheduling
- Shaping
The tests are divided into individual tests 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 full load.
This involves concurrent testing of multiple interfaces with the
specific traffic management function enabled, and doing so to the
capacity limit of each interface.
As an example: a device is specified to be capable of shaping on all
of it's egress ports. The individual test would first be conducted to
benchmark the advertised 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 a requirement for the TCP
stateful tests, which require network delay to allow TCP to fully
open the TCP window. Also note that the Network Delay Emulator (NDE)
should be passive in nature such as 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 that 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
DUT would be removed and the NDE performance benchmarked
independently.
Note the NDE should be used in "full pipe" delay mode. 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, 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 BDPs for the TCP stateful tests.
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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 RFC 2119 [RFC2119].
The following acronyms are used:
BB: Bottleneck Bandwidth
BDP: Bandwidth Delay Product
BSA: Burst Size Achieved
CBS: Committed Burst Size
CIR: Committed Information Rate
DUT: Device Under Test
EBS: Excess Burst Size
EIR: Excess Information Rate
NDE: Network Delay Emulator
SP: Strict Priority Queuing
QL: Queue Length
QoS: Quality of Service
RED: Random Early Discard
RTT: Round Trip Time
SBB: Shaper Burst Bytes
SBI: Shaper Burst Interval
SR: Shaper Rate
SSB: Send Socket Buffer
Tc: CBS Time Interval
Te: EBS Time Interval
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Ti Transmission Interval
TTP: TCP Test Pattern
TTPET: TCP Test Pattern Execution Time
WRED: Weighted Random Early Discard
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.)
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 that
a network device can sustain without dropping or impairing packets,
or 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 criterion, which is
not within the charter of 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, this framework describes 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 scope of this framework to specify the procedure for
testing multiple traffic management functions concurrently. The
multitudes of possible combinations is almost unbounded and the
ability to identify functional "break points" would be most times
impossible.
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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. Traffic
management specifications largely do not exist and this is a prime
driver for this framework; to provide an objective means to compare
vendor traffic management functions.
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.)
And finally, this framework will provide references to open source
tools that can be used to provide stateless and/or stateful
traffic generation emulation.
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 segment layer metrics used for the stateful traffic
testing.
4.1. Metrics for Stateless Traffic Tests
For the stateless traffic tests, the metrics are defined at the layer
3 packet level versus layer 2 packet level for consistency.
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Stateless traffic measurements require that sequence number and
time-stamp 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, RFC 4689 provides
recommendations for sequence tracking along with definitions of
in-sequence and out-of-order packets.
The following are the metrics to be used 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
Burst Size Achieved metric is a measure of the actual burst size
received at the egress port of the DUT with no lost packets. As an
example, the configured CBS of a DUT is 64KB and after the burst test,
only a 63 KB can be achieved without packet loss. Then 63KB 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.
- 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. RFC 4737 and RFC 2680 describe the need to
to establish the time threshold to wait before a packet is declared
as lost. packet as lost, and this threshold MUST be reported with
the results.
- Out of Sequence (OOS): in additions to the LP metric, the test
packets must be monitored for sequence and the out-of-sequence (OOS)
packets. RFC 4689 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 RFC 4737 and RFC 2680.
- Packet Delay (PD): the Packet Delay metric is the difference between
the timestamp of the received egress port packets and the packets
transmitted into the ingress port and specified in RFC 2285.
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- Packet Delay Variation (PDV): the Packet Delay Variation metric is
the variation between the timestamp of the received egress port
packets and specified in RFC 5481.
- Shaper Rate (SR): the Shaper Rate is only applicable to the
traffic shaping tests. The SR represents the average egress output
rate (bps) over the test interval.
- Shaper Burst Bytes (SBB): the Shaper Burst Bytes is
only applicable to the traffic shaping tests. A traffic shaper will
emit packets in different size "trains" (bytes back-to-back). This
metric characterizes the method by which the shaper emits traffic.
Some shapers transmit larger bursts per interval, while other shapers
may transmit a single frame at the CIR rate (two extreme examples).
- Shaper Burst Interval(SBI): the interval is only applicable to the
traffic shaping tests and again is the time between a shaper emitted
bursts.
4.2. Metrics for Stateful Traffic Tests
The stateful metrics will be based on RFC 6349 TCP metrics and will
include:
- TCP Test Pattern Execution Time (TTPET): RFC 6349 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, database applications,
etc. 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.
An example would be an interactive HTTP TTP session which 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: average of 6.5
seconds, minimum of 5.0 seconds, and maximum of 7.9 seconds.
- TCP Efficiency: after the execution of the TCP Test Pattern, TCP
Efficiency represents the percentage of Bytes that were not
retransmitted.
Transmitted Bytes - Retransmitted Bytes
TCP Efficiency % = --------------------------------------- X 100
Transmitted Bytes
Transmitted Bytes are the total number of TCP Bytes to be transmitted
including the original and the retransmitted Bytes. These retransmitted
bytes should be recorded from the sender's TCP/IP stack perspective,
to avoid any misinterpretation that a reordered packet is a retransmitted
packet (as may be the case with packet decode interpretation).
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- 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 RFC 6349. Referencing RFC 6349, 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.
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 RFC 6349,
retransmitted packets should not be used in RTT measurements.
Also, the test results should record the average RTT in millisecond
across the entire test duration and 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 set must be capable of generating traffic at up to the
link speed of the DUT. The test set must be calibrated to verify
that it will not drop any packets. The test set's inherent PD and PDV
must also be calibrated and subtracted from the PD and PDV metrics.
The test set must support the encapsulation to be tested such as
VLAN, Q-in-Q, MPLS, etc. Also, the test set must allow control of
the classification techniques defined in RFC 4689 (i.e. IP address,
DSCP, TOS, etc classification).
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. GigE, 10 GigE, etc.). Careful calibration of any test
environment using iperf is important. At higher link speeds, it is
recommended to use hardware based packet test equipment.
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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 traffic management function, since burst
parameters of SLAs are specified in bytes. For testing efficiency,
it is recommended to include a burst hunt feature, which automates
the manual process of determining the maximum burst size which 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.
Optionally for a policer function and 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 RFC 6349. 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
(NDE function from the lab set-up diagram) must be used in order to provide a
meaningful BDP. As referenced in section 2, the target traffic rate and
configured RTT must be verified independently using just the NDE for all
stateful tests (to ensure the NDE can delay without loss).
The TCP test host must be capable to generate and receive 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.
The TCP test host must allow adjusting both Send and Receive Socket
Buffer sizes. The Socket Buffers must be large enough to fill the BDP
for bulk transfer 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 (i.e. OS version, i.e. LINUX OS kernel using TCP New Reno,
TCP options supported, etc.).
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While RFC 6349 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, business applications, etc. This interactive traffic is
bi-directional and can be chatty.
The test device must not only support bulk TCP transfer application
traffic but also 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
open source tool "Flowgrind" (referenced in Appendix A) is
client-server based and emulates interactive applications at the TCP
layer. 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 links 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 which is another reason why stateful TCP test traffic must
be used.
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 100ms |
Browser <------------------------ Server
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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 millisecond). This asynchronous, "request/
response" behavior is intrinsic to most TCP based applications such
as Email (SMTP), File Transfers (FTP and SMB), Database (SQL), Web
Applications (SOAP), REST, etc. The impact to the network elements is
due to the multitudes of Clients and the variety of bursty traffic,
which stresses 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.
There are two (2) techniques recommended by this framework to develop
standard TCP test patterns for traffic management benchmarking.
The first technique involves modeling, which have been described in
"3GPP2 C.R1002-0 v1.0" and describe the behavior of HTTP, FTP, and
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 Flowgrind tool (Appendix A)
supports many of the distributions and is a good choice as long as
the processing limits of the server platform are taken into
consideration.
The second technique is to conduct packet captures of the
applications to test and then to statefully play the application back
at the TCP layer. The TCP playback includes the request byte size,
response byte size, and inter-message gaps at both the client and the
server. The advantage of this method is that very realistic test
patterns can be defined based on real world application traffic.
This framework does not specify a fixed set of TCP test patterns, but
does provide recommended test cases in Appendix B. Some of these examples
reflect those specified in "draft-ietf-bmwg-ca-bench-meth-04" which
suggests traffic mixes for a variety of representative application
profiles. Other examples are simply well known application traffic
types.
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6. Traffic Benchmarking Methodology
The traffic benchmarking methodology uses the test set-up from
section 2 and metrics defined in section 4. Each test should be run
for a minimum test time of 5 minutes.
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 that are defined in each
subsection.
6.1. Policing Tests
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-back packet testing concepts from RFC 2544 (but adapted
to burst size algorithms and terminology). Also MEF-14,19,37 provide
some basis for 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 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
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.
The policer test shall test a policer as defined by RFC 4115 or
MEF 10.2, depending upon the equipment's specification. As an example
for RFC 4115, consider a CBS and EBS of 64KB and CIR and EIR of
100 Mbps on a 1GigE physical link (in color-blind mode). A stateless
traffic burst of 64KB would be sent into the policer at the GigE rate.
This equates to approximately a 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 millisecond in this example.
The metrics defined in section 4.1 shall be measured at the egress
port and recorded.
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 police at the specified CBS/EBS values.
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For this portion of the test, the CBS/EBS value should be incremented
by 1000 bytes higher than the configured CBS and that the egress port
measurements must show that the excess packets are dropped.
Additional tests beyond the simple color-blind example might include:
color-aware mode, configurations where EIR is greater than CIR, etc.
6.1.2 Policer Capacity Tests
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.
As an 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).
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 methodology described
in Section 6.1.1 for a single policer should be applied to each of
the physical port policers.
6.1.2.1 Maximum Policers on Single Physical Port
The first policer capacity test will benchmark a single physical port,
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, double tagged vlan,
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
Some bandwidth on the physical port is dedicated for other traffic (non
customer traffic); this includes network control protocol traffic. There
is a separate policer for the other traffic. Typical deployments have 3
categories of policers; there may be some deployments with more or less
than 3 categories of ingress policers.
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6.1.2.2 Single Policer on All Physical Ports
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 the physical ports in the networking device are
active.
6.1.2.3 Maximum Policers on All Physical Ports
Finally the third policer capacity test involves a combination of the
first and second capacity test, namely maximum policers active per
physical port and all physical ports are active .
6.2. Queue and Scheduler Tests
Queues and traffic Scheduling are closely related in that a queue's
priority dictates the manner in which the traffic scheduler's
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, the 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), Weighted Fair Queueing (WFQ) along with other
variations. This test framework recommends to test at a minimum
of three techniques although it is the discretion of the tester
to benchmark other device scheduling algorithms.
6.2.1.1 Testing Queue/Scheduler with Stateless Traffic
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 (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. This
gap is referred to as the transmission interval (Ti). Ti can
be defined for the traffic bursts and is based off of the QL and
Bottleneck Bandwidth (BB) of the egress interface.
Ti = QL * 8 / BB
Note that this equation is similar to the Ti required for transmission
into a policer (QL = CBS, BB = CIR). Also note that the burst hunt
algorithm defined in section 5.1.1 can also be used to automate the
measurement of the queue value.
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The stateless traffic burst shall be transmitted at the link speed
and spaced within the Ti time interval. The metrics defined in section
4.1 shall be measured at the egress port and recorded; the primary
result is to verify the BSA and 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 2 levels of priority including SP and FIFO
queueing. Under a flow load greater 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.
6.2.1.2 Testing Queue/Scheduler with Stateful Traffic
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 set-up configuration in
section 2.
The BDP of the TCP test traffic must be calibrated to the QL of the
device queue. Referencing RFC 6349, the BDP is equal to:
BB * RTT / 8 (in bytes)
The NDE must be configured to an RTT value which 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 = 32KB
RTT(min) = QL * 8 / BB and would equal 2.56 millisecond (and the
BDP = 32KB)
In this example, one (1) TCP connection with window size / SSB of
32KB would be required to test the QL of 32KB. This Bulk Transfer
Test can be accomplished using iperf as described in Appendix A.
Two types of TCP tests must be performed: Bulk Transfer test and 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 emulates application layer bursting
which may occur any time during the TCP connection.
Other tests types should include: Simple Web Site, Complex Web Site,
Business Applications, Email, SMB/CIFS File Copy (which are also
documented in Appendix B).
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.
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6.2.2 Queue / Scheduler Capacity Tests
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. This test 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.
6.2.2.1 Multiple Queues / Single Port Active
For the first scheduler / queue capacity test, multiple queues per
port will be tested on a single physical port. In this case,
all the queues (typically 8) are active on a single physical port.
Traffic from multiple ingress physical ports are directed to the
same egress physical port which 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
For this test, Strict Priority (SP) scheduling on the egress
physical port should be tested and the benchmarking methodology
specified in section 6.2.1 should be applied here. For a given
priority, each ingress physical port should get a fair share of
the egress physical port bandwidth.
6.2.2.1.2 Strict Priority + Weighted Fair Queue (WFQ) on Egress Port
For this test, Strict Priority (SP) and Weighted Fair Queue (WFQ)
should be enabled simultaneously in the scheduler but on a single
egress port. The benchmarking methodology specified in Section 6.2.1
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.
6.2.2.2 Single Queue per Port / All Ports Active
Traffic from multiple ingress physical ports are directed to the
same egress physical port, which will cause oversubscription on the
egress physical port. Also, the same amount of traffic is directed
to each egress physical port.
The benchmarking methodology specified in Section 6.2.1 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.
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6.2.2.3 Multiple Queues per Port, All Ports Active
Traffic from multiple ingress physical ports are directed to all
queues of each egress physical port, which will cause
oversubscription on the egress physical ports. Also, the same
amount of traffic is directed to each egress physical port.
The benchmarking methodology specified in Section 6.2.1 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.
6.3. Shaper tests
A traffic shaper is memory based like a queue, but with the added
intelligence of an active shaping element. The same concepts from
section 6.2 (Queue testing) can be applied to testing 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, 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 Shaper Rate and
Bc/Be parameters. Shapers generally transmit into policers, so
the idea is for the emitted traffic to conform to the policer's
limits.
The stateless and stateful traffic test sections describe the
techniques to transmit bursts into the DUT's ingress port
and the metrics to benchmark at the shaper egress port.
6.3.1.1 Testing Shaper with Stateless Traffic
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
Ti (Time interval) must be large enough so that the Shaper Rate is
not exceeded. An example will clarify single and multiple burst
test cases.
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In the 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 Shaper Rate = 50 Mbps, and both Bc/Be 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. The egress port metrics from section 4.1
will be recorded with particular emphasis on the LP, PDV, SBB, and
SBI metrics.
If a multiple burst test is to be conducted, then the burst bytes
divided by the time interval between the 512,000 byte bursts must
not exceed the Shaper Rate. The time interval (Ti) must adhere to
a similar formula as described in section 6.2.1.1 for queues, namely:
Ti = Ingress Queue x 8 / Shaper Rate
So for the example from the previous paragraph, Ti between bursts must
be greater than 82 millisecond (512,000 bytes x 8 / 50,000,000 bps).
This yields an average rate of 50 Mbps so that an Input Queue
would not overflow.
6.3.1.2 Testing Shaper with Stateful Traffic
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 set-up
configuration in section 2.
The BDP of the TCP test traffic must be calculated as described in
section 6.2.2. To properly stress network buffers and the traffic
shaping function, the cumulative TCP window should exceed the BDP
which will stress the shaper. BDP factors of 1.1 to 1.5 are
recommended, but the values are the discretion of the tester and
should be documented.
The cumulative TCP Window Sizes* (RWND at the receiving end & CWND
at the transmitting end) equates to:
TCP window size* for each connection x number of connections
* as described in section 3 of RFC6349, the SSB MUST be large
enough to fill the BDP
Example, if the BDP is equal to 256 Kbytes and a connection size of
64Kbytes is used for each connection, then it would require four (4)
connections to fill the BDP and 5-6 connections (over subscribe the
BDP) to stress test the traffic shaping function.
Two types of TCP tests must be performed: Bulk Transfer test and 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 emulates application layer bursting
which may any time during the TCP connection.
Other tests types should include: Simple Web Site, Complex Web Site,
Business Applications, Email, SMB/CIFS File Copy (which are also
documented in Appendix B).
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.
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6.3.2 Shaper Capacity Tests
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. This test will benchmark the maximum
number of shapers as specified by the device manufacturer.
For all of the capacity tests, the benchmarking methodology described
in Section 6.3.1 for a single shaper should be applied to each of the
physical port and/or queue shapers.
6.3.2.1 Single Queue Shaped, All Physical Ports Active
The first shaper capacity test involves per port shaping, all physical
ports active. Traffic from multiple ingress physical ports are directed
to the same egress physical port and this will cause oversubscription
on the egress physical port. Also, the same amount of traffic is
directed to each egress physical port.
The benchmarking methodology described in Section 6.3.1 should be
applied to each of the physical ports. Each ingress physical port
should get a fair share of the egress physical port bandwidth.
6.3.2.2 All Queues Shaped, Single Port Active
The second shaper capacity test is conducted with all queues actively
shaping on a single physical port. The benchmarking methodology
described in per port shaping test (previous section) 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 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.
6.3.2.3 All Queues Shaped, All Ports Active
And for the third shaper capacity test (which is a combination of the
tests in the previous two sections),all queues will be actively
shaping and all physical ports active.
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6.4 Concurrent Capacity Load Tests
As mentioned in the scope 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 which may be useful
to test under capacity as well:
- Policers on ingress and queuing on egress
- Policers on ingress and shapers on egress (not intended for a
flow to be policed then shaped, these would be two different
flows tested at the same time)
- etc.
Appendix A: Open Source Tools for Traffic Management Testing
This framework specifies that stateless and stateful behaviors should
both be tested. Two (2) open source tools that can be used are iperf
and Flowgrind to accomplish many of the tests proposed in this
framework.
Iperf can generate UDP 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 uni-directional and bi-directional 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 are provided by the iperf receiver.
The TCP mode can be used for stateful traffic testing to test bulk
transfer traffic. The TCP Window size (which is actually the SSB),
the number of connections, the packet size, TCP port and the test
duration can be controlled. A report of bytes transmitted and
throughput achieved are provided by the iperf sender.
Flowgrind is a distributed network performance measurement tool.
Using the flowgrind controller, tests can be setup between hosts
running flowgrind. For the purposes of this traffic management
testing framework, the key benefit of Flowgrind is that it can
emulate non-bulk transfer applications such as HTTP, Email, etc.
This is due to fact that Flowgrind supports the concept of request
and response behavior while iperf does not.
Traffic generation options include the request size, response size,
inter-request gap, and response time gap. Additionally, various
distribution types are supported including constant, normal,
exponential, pareto, etc. These traffic generation parameters
facilitate the emulation of some of the TCP test patterns
which are discussed in Appendix B.
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Since these tools are software based, the host hardware must be
qualified as capable of generating the target traffic loads
without packet loss and within the packet delay variation threshold.
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 RFC 6349 are used to create this TCP traffic pattern.
- Micro Burst: generate precise burst patterns within a single or multiple
TCP connections(s). 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 from "3GPP2 C.R1002-0 v1.0"
is referenced (Table 4.1.3.2-1) 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)
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 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
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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.
- Inter-active Patterns: While Web site patterns are inter-active
to a degree, they mainly emulate the downloading of various
complexity web sites. Inter-active patterns are more chatty in nature
since there is alot of user interaction with the servers. Examples
include business applications such as Peoplesoft, Oracle and consumer
applications such as Facebook, IM, etc. For the inter-active patterns,
the packet capture technique was used to characterize some business
applications and also the email application.
In summary, an inter-active 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 inter-active applications
Again using packet capture as a means to characterize, the following
table reflects the guidelines for Simple Business Application, Complex
Business Application, eCommerce, and Email Send / Receive:
Simple Complex
Parameter Biz. App. Biz. App 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 from "SPECweb2009" (need proper reference)
** The client and server processing time is distributed across the
transmission / receipt of all of messages. Client processing time
consists mainly of the delay between user interactions (not machine
processing).
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And 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 th file transfer.
Again using packet capture as a means to characterize the following
table reflects the guidelines for SMB/CIFS file copy:
SMB
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 64KB 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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7. Security Considerations
8. IANA Considerations
9. Conclusions
10. References
10.1. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[2] Crocker, D. and Overell, P.(Editors), "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, Internet Mail Consortium and
Demon Internet Ltd., November 1997.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2234] Crocker, D. and Overell, P.(Editors), "Augmented BNF for
Syntax Specifications: ABNF", RFC 2234, Internet Mail
Consortium and Demon Internet Ltd., November 1997.
10.2. Informative References
11. Acknowledgments
Authors' Addresses
Barry Constantine
JDSU, Test and Measurement Division
Germantown, MD 20876-7100, USA
Phone: +1 240 404 2227
Email: barry.constantine@jdsu.com
Timothy Copley
Level 3 Communications
14605 S 50th Street
Phoenix, AZ 85044
Email: Timothy.copley@level3.com
Ram Krishnan
Brocade Communications
San Jose, 95134, USA
Phone: +001-408-406-7890
Email: ramk@brocade.com
Constantine June 25, 2014 [Page 26]
