Network Simulator 2

Introduction

Open source network simulator NS uses two languages: C++ and OTcl

C++ is fast to run but slower to change Kernel

OTcl runs much slower but can be changed very quickly

Simulation Model

Support Linux and Windows

OTcl

Tcl introductionCross-platform, extensible, scripting language Interpreter languageEasy to use

OTcl = Object Tcl

Simulation Step

1. Creating network model Node, link, etc…

2. Creating traffic model Traffic generator agent TCP/UDP agent

3. Simulation starting

4. Packet trace and gather statistics

5. Result analysis

Homework 1/4

Studying to use ns2 to simulate TCP Network Network model:

Generating network model according to following graphic：

0

2

1 5

6

7

8

3 4

Homework 2/4

Network model : For all link:

Duplex Bandwidth set to 10Mbps

Traffic model: Setup a FTP over TCP connection from node 8 to

node 0 Setup a CBR over UDP connection from node 3 to

node 6 Set the starting time by yourself

Homework 3/4

Simulation: Changing the CBR data rate to 1, 4, 8Mbps Packet size 500 Run simulation Simulation time 100s

Packet trace and gather statistics End to end delay Throughput Deliver rate Graphic

Homework 4/4

Result analysis Explain the relationship between

Data rate Time End to end delay Throughput Deliver rate

Explain the reason why packet loss

Deadline : 11/25

Conference

http://www.isi.edu/nsnam/ns/ http://140.116.72.80/~smallko/ns2/ns2.htm http://nile.wpi.edu/NS/ http://www.isi.edu/nsnam/ns/tutorial/ http://www.isi.edu/nsnam/ns/ns-document

ation.html