HP HP-UX IPQos White Paper

HP-UX IPQoS Performance and Sizing White Paper

November 2005

Abstract.............................................................................................................................................. 2

Introduction......................................................................................................................................... 2

Tool Used for Measuring Performance.................................................................................................... 3

Test Configuration................................................................................................................................ 3

Interpretation of Results......................................................................................................................... 4

Raw Data ........................................................................................................................................... 5

Future Tests ......................................................................................................................................... 7

Abstract

This document outlines the performance impact of HP-UX IPQoS on an HP-UX system. It is divided into
five sections. The first section is an introduction to IPQoS; the second section is about the tool used for
the tests; the third section gives an overview of test configuration; the fourth section gives an
interpretation of the test results; the fifth section contains raw test result data in tabular form; and the
last section gives some suggestions for further study.

Introduction

During the past few years, the Internet has evolved from a simple network carrying primarily data
traffic, into a complex network handling a variety of traffic, ranging from real time audio and video to
web traffic. However, in terms of throughput, delay and packet loss, the “best effort” nature of the
current Internet is not sufficient to cope with the requirements of this type of traffic.

HP-UX IPQoS can be used to bring an HP-UX node into conformance with the IETF Differentiated
Services (DiffServ) model. The key features of HP-UX IPQoS are:

• Conforms to the IETF Differentiated Services (DiffServ) Model.

• Provides differentiated classes of service on outbound traffic by performing traffic

conditioning actions. Important traffic classes can take bandwidth away from less important
classes, up to user-specified limits.

- Classification occurs when traffic classes are defined in filters.

- Marking occurs when marking attributes are set in policies.

- Metering occurs when bandwidth is reserved for defined traffic classes

in policies.

• Allows DSCP and VLAN marking on outbound traffic from the HP-UX server.

- Can assign different DSCP network routing priorities (valid range 0-63).

- Can assigned different VLAN priorities (valid range 0-7).

• Supports traffic classification on broad range of packet attributes.

• Provides provisioned QoS management.

• Supports both IPv4 and IPv6.

HP-UX IPQoS performs the above items by reading the header of an IP packet (plus transport
TCP/UDP header) and comparing it to a set of user configured rules. The specific action is taken
based on the rules. Because HP-UX IPQoS only reads the IP header, the size of an IP packet does not
affect the speed at which HP-UX IPQoS processes the packet.

However, the faster an interface connection is, the more packets per second it can handle. A link
capable of 56 Kbps and 1.544Mbps can carry up to 350 and 9650 packets per second,
respectively. Faster connections such as 10-baseT (Ethernet) and 100-baseT (Fast Ethernet) can carry
up to 62,500 and 625,000 packets respectively.

Because HP-UX IPQoS works the same on all packets, regardless of size, the more packets an
interface can handle the more checking HP-UX IPQoS has to do. Therefore, the impact of HP-UX
IPQoS on a slower interface is minimal because there are not as many packets for it to check. The
performance impact of HP-UX IPQoS on a faster interface is greater, because more packets are
passing through, and HP-UX IPQoS must process them all.

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Tool Used for Measuring Performance

The tool used for measuring the performance of HP-UX IPQoS is netperf. Developed by HP, this tool is
distributed in source form at www.netperf.org
The netperf tool has two executables: netperf and netserver. netserver can run as a child process to
inetd. In that case, netserver should be added to the /etc/inetd.conf
standalone daemon.

Two systems are required to test HP-UX IPQoS. One system runs netserver (the remote system) and the
other system runs netperf (the local system). By default, netperf is installed in the /opt/netperf
directory (it is possible to install it in a different directory, but changes must be made to the netperf
makefiles). The remote system must have an entry for netserver in the /etc/inetd.conf
system must have an entry for netperf in the /etc/services
port number 12865. After the /etc/inetd.conf
the remote system using kill –HUP <PID#>.

netperf provides many scripts for running different tests. See the netperf manpages for a detailed
description of these scripts.

The most common use of netperf is measuring bulk data transfer performance. This is also referred to
as "stream" or "unidirectional stream" performance. Essentially, these tests will measure how fast one
system can send data to another and/or how fast that other system can receive it.

. This site is informally maintained by Hewlett-Packard.

file. netserver can also run as a

file and the local

files identifying that netperf is using TCP

file is edited, make sure to update the inetd daemon on

Test Configuration

The tests were done on two systems; one running HP-UX 11i v1 and the other running HP-UX 11i v2
(update 2). The two systems, connected back to back with a crossover cable, were used for the
netperf tests. HP-UX IPQoS A.01.00 was only installed on the HP-UX 11i v2 system (rp3440, 4 CPU).
The other system was running HP-UX 11i v1 (rp4440, 6 CPU) without HP-UX IPQoS installed. While
testing, care should be taken to make sure that other network traffic does not interfere with the traffic
generated by the tests. This can be achieved by performing all the tests in a private LAN.

Tests were done on both 100BaseT and 1000BaseT interfaces with the different HP-UX IPQoS
configurations occurring on the local system. As specified, the remote system was running
HP-UX 11i v1 without HP-UX IPQoS installed.

On the local system (HPUX 11i v2), the tests were done twice; once with HP-UX IPQoS installed
(pushed) but with no filters or policies (rules) configured. In this case HP-UX IPQoS only plays the role
of “pass-through”. The second time, HP-UX IPQoS was configured with a simple filter and policy.
Note: tests did not specify any bandwidth reservation since the purpose of the tests was to see the
performance impact of HP-UX IPQoS on the HP-UX operating system. The simple filter and policy used
for the tests was:

HP-UX IPQoS is ENABLED and FILTERING.
Name: current
Adapter: lan1 (00:0e:7f:4e:bf:88) Type: Ethernet Speed: 100 Mbps
Policy: p1
DSCP: 20
Filter: f1
Transport protocol: 6 (tcp)
Priority: 0

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