Ns Network Simulator for Beginners

✍ Scribed by Eitan Altman, Tania Jimenez

• Publisher: Morgan & Claypool
• Year: 2012
• Tongue: English
• Leaves: 184
• Series: Synthesis Lectures on Communication Networks
• Edition: 1
• Category: Library

✦ Synopsis

NS-2 is an open-source discrete event network simulator which is widely used by both the research community as well as by the people involved in the standardization protocols of IETF. The goal of this book is twofold: on one hand to learn how to use the NS-2 simulator, and on the other hand, to become acquainted with and to understand the operation of some of the simulated objects using NS-2 simulations. The book is intended to help students, engineers or researchers who need not have much background in programming or who want to learn through simple examples how to analyse some simulated objects using NS-2. Simulations may differ from each other in many aspects: the applications, topologies, parameters of network objects (links, nodes) and protocols used, etc. The first chapter is a general introduction to the book, where the importance of NS-2 as a tool for a good comprehension of networks and protocols is stated. In the next chapters we present special topics as TCP, RED, etc., using NS-2 as a tool for better understanding the protocols. We provide in the appendices a review of Random Variables and Confidence Intervals, as well as a first sketch for using the new NS-3 simulator. Table of Contents: Introduction / NS-2 Simulator Preliminaries / How to work with trace files / Description and simulation of TCP/IP / Routing and network dynamics / RED: Random Early Discard / Differentiated Services / Mobile Networks and Wireless Local Area Networks / Classical queueing models / Tcl and C++ linkage

✦ Table of Contents

Preface......Page 13
NS-2 as a tool for designing Internet protocols......Page 15
NS-2, NS-3 and other simulators......Page 16
Further background on NS-2 simulator......Page 19
Tcl and Otcl programming......Page 20
Initialization and termination......Page 27
Definition of a network of links and nodes......Page 28
FTP over TCP......Page 31
CBR over UDP......Page 32
Scheduling events in NS-2......Page 33
Visualisation using nam......Page 36
Structure of trace files......Page 38
Seeds and generators......Page 40
Creating Random Variables in NS-2......Page 41
Processing data files with awk......Page 45
Processing data files with perl......Page 47
Plotting with gnuplot......Page 49
Plotting with xgraph......Page 50
Extracting information within a tcl script......Page 51
Acknowledgements......Page 53
Initiating a connection......Page 55
Tracing and analysis of Example ex1.tcl......Page 56
TCP over noisy links and queue monitoring......Page 57
Creating many connections with random features......Page 62
Short TCP connections......Page 65
Advanced monitoring tools......Page 73
Exercises......Page 77
Unicast routing......Page 79
Multicast protocols......Page 82
Routing based on a RV point......Page 83
Simulating multicast routing......Page 84
Routing with a centralized RV point......Page 87
Observations on the simulation of pimdm.tcl......Page 89
Exercises......Page 90
Description of RED......Page 91
Setting RED parameters in NS-2......Page 92
Drop tail buffer......Page 93
RED buffer with automatic parameter configuration......Page 98
Monitoring flows......Page 102
Exercises......Page 108
Description of assured forwarding Diffserv......Page 109
Configuration of MRED in NS-2......Page 110
TCL querying......Page 111
Description......Page 112
TCL querying......Page 113
The simulated scenario......Page 114
Simulation results......Page 122
Discussions and conclusions......Page 123
Exercises......Page 124
Mobile Networks and Wireless Local Area Networks......Page 125
Ad-hoc On Demand Distance Vector - AODV......Page 126
Dynamic Source Routing - DSR......Page 127
Temporally Ordered Routing Algorithm - TORA......Page 128
Writing the tcl script......Page 129
Trace format......Page 131
Analysis of simulation results......Page 135
TCP over DSR......Page 136
TCP over AODV......Page 137
TCP over TORA......Page 138
Background......Page 139
The simulated scenario......Page 140
Simulation results......Page 143
Exercises......Page 146
Simulating an M/M/1, M/D/1 and D/M/1 queues......Page 147
Finite queue......Page 150
Exercises......Page 151
Tcl and C++ linkage......Page 153
Appendix I: Random variables: background......Page 159
Appendix II: Confidence intervals......Page 163
Definition of a network topology in NS-3......Page 165
Transport Protocols and Applications in NS-3......Page 166
Creating Random Variables in NS-3......Page 167
Short overview of TCP in NS-3......Page 168
Simulating classical queueing models in NS-3......Page 172
Bibliography......Page 177
Authors' Biographies......Page 183