HP-UX TCP/IP Performance White Paper, March 2008

1 Introduction

This white paper is intended as a guide to tuning networking performance at the network and transport

layers. This includes IPv4, IPv6, TCP, UDP, and related protocols. Some topics will touch on other areas

including sockets interfaces, network interface drivers and application protocols; however that is not the

focus of this paper. Other information is available for these subsystems as referenced below.

1.1 Intended Audience

This whitepaper is intended for the following:

• Administrators responsible for supporting or tuning the internal workings of the HP-UX networking

stack

• Network programmers, for example those who directly write to the TCP or UDP protocols using

socket system calls

• HP-UX network and system administrators who want to supplement their knowledge of HP-UX

configuration options

NOTE: This white paper is specific to performance tuning, and is not a general guide to HP-UX network

administration.

1.2 Organization of the document

This document is organized as follows:

Chapter 1: Introduction.

Chapter 2: Provides information on out of the box TCP/IP performance features.

Chapter 3: Provides information on advanced out of the box scalability and performance

features.

Chapter 4: Provides recommendations on tuning HP-UX servers.

Chapter 5: Provides information on tuning applications using programmatic interfaces.

Chapter 6: Provides information on how to monitor and troubleshoot network performance on

HP- UX.

Appendix A: Provides detailed description of netstat statistics and related tuning.

Appendix B: Provides detailed description of TCP/IP ndd tunables.

1.3 Related Documents

The following documentation supplements information in this document:

• HP-UX 11i v3 performance further increases your productivity for improved IT business value

http://h71028.www7.hp.com/ERC/downloads/4AA1-0961ENW.pdf

• Performance and Recommended Use of AB287A 10 Gigabit Ethernet Cards

http://docs.hp.com/en/10gigEwhitepaper.pdf/10Gige_arches_whitepaper_version5.pdf

• HP Auto Port Aggregation Performance and Scalability White Paper

http://docs.hp.com/en/7662/new-apa-white-paper.pdf

• Network Server Accelerator White Paper

http://www.docs.hp.com/en/NSAWP-90902/NSAWP-90902.pdf

• RFCs related to TCP/IP Performance:

http://www.ietf.org/rfc.html

§ RFC 1323: TCP Extensions for High Performance

§ RFC 2001: TCP Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery

Algorithms