How to Start TCP Protocols Projects Using NS2

To start a TCP Protocol project using Network Simulator 2 (NS2) that needs to replicate the behavior of Transmission Control Protocol (TCP) within a network. NS2 environment have numerous TCP aspects like TCP Tahoe, TCP Reno, TCP NewReno, and TCP Vegas that permitting comprehensive analysis and comparison. Following is a detailed approach to get started:

Steps to Start TCP Protocols Projects in NS2

  1. Understand TCP and NS2 Capabilities
  • TCP Overview:
    • TCP is a reliable transport layer protocol, which supports end-to-end interaction.
    • It requires algorithms such as congestion control, flow control, and error retrieval.
  • NS2 Features:
    • It has several TCP flavors like Tahoe, Reno, NewReno, Vegas, SackTCP, and so on.
    • Permits congestion control mechanisms and throughput for in-depth analysis.
  1. Set Up Your Environment
  • Install NS2:

sudo apt-get install ns2

  • Confirm installation by executing an example simulation script:

ns example.tcl

  1. Define the Project Scope
  • Objectives:
    • Replicate the TCP flows under diverse network conditions.
    • Equate TCP variants like Reno vs NewReno.
    • Examine the performance parameters like throughput, packet loss, and latency.
  • Examples:
    • Replicate TCP congestion control within a blockage link situation.
    • Measure the performance of TCP under high-latency networks.
    • Execute and experiment the changes for TCP mechanisms.
  1. Design the Network Topology
  • Topology Elements:
    • Sender nodes: It makes TCP traffic.
    • Receiver nodes: It helps to obtain the TCP traffic.
    • Routers: Mimic intermediate network modules.
    • Links: It supports to describe the bandwidth, delay, and queue types.
  • Example Topology:
    • We can consider a simple network has 2 sender nodes, 2 receiver nodes, and a blockage router.
  1. Write the TCL Script
  • Describe the nodes, links, TCP agents, and traffic sources applying tcl script.

Example TCL Script for TCP Reno Simulation:

# Initialize the simulator

set ns [new Simulator]

# Open trace and NAM files

set tracefile [open tcp_trace.tr w]

$ns trace-all $tracefile

set namfile [open tcp_simulation.nam w]

$ns namtrace-all $namfile

# Create nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

# Connect nodes

$ns duplex-link $n0 $n2 1Mb 10ms DropTail

$ns duplex-link $n1 $n2 1Mb 10ms DropTail

$ns duplex-link $n2 $n3 500Kb 20ms DropTail

# Configure TCP agents

set tcp1 [new Agent/TCP]

$tcp1 set class_ 1

$tcp1 set window_ 32

$tcp1 set tcpTick_ 0.01

$tcp1 set flavor_ “Reno”

$ns attach-agent $n0 $tcp1

set tcp2 [new Agent/TCP]

$tcp2 set class_ 1

$tcp2 set window_ 32

$tcp2 set tcpTick_ 0.01

$tcp2 set flavor_ “Reno”

$ns attach-agent $n1 $tcp2

# Configure TCP sinks

set sink1 [new Agent/TCPSink]

$ns attach-agent $n3 $sink1

$ns connect $tcp1 $sink1

set sink2 [new Agent/TCPSink]

$ns attach-agent $n3 $sink2

$ns connect $tcp2 $sink2

# Add traffic sources

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 1.0 “$ftp1 start”

$ns at 10.0 “$ftp1 stop”

set ftp2 [new Appliation/FTP]

$ftp2 attach-agent $tcp2

$ns at 2.0 “$ftp2 start”

$ns at 10.0 “$ftp2 stop”

# Terminate simulation

$ns at 15.0 “finish”

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam tcp_simulation.nam &

exit 0

}

$ns run

  1. Simulate Network Dynamics
  • Congestion: Launch a blockage connection for analysing the TCP congestion control.
  • Packet Loss: Replicate packet drops with the support of random loss models:

set loss_module [new ErrorModel]

$loss_module set rate_ 0.01

$loss_module ranvar [new RandomVariable/Uniform]

$loss_module drop-target [new Agent/Null]

$ns loss-model $loss_module $link

  1. Run the Simulation
  • We can run the tcl simulation script using NS2:

ns tcp_simulation.tcl

  • Utilize NAM to envision the network:

nam tcp_simulation.nam

  1. Analyze Performance
  • From the trace file as tcp_trace.tr, we will need to obtain performance parameters:
    • Throughput: Compute the volume of data that are sent for each second.
    • Packet Loss: Estimate the volume of packets which are lost in the course of transmission.
    • Latency: Assess the duration, attaining the destination nodes for packets.

Example AWK Script for Throughput:

BEGIN {bytes=0; time=0;}

{

if ($1 == “r” && $4 == “TCP”) {

bytes += $6;

time = $2;

}

}

END {

print “Throughput (kbps):”, (bytes * 8 / time) / 1000;

}

  1. Extend the Project
  • Compare TCP Variants:
    • Exchange Reno including NewReno, Tahoe, or Vegas to apply tcp1 and tcp2 set up.

$tcp1 set flavor_ “Vegas”

  • Modify Congestion Control:
    • Execute the new congestion control mechanisms by means of prolonging TCP within NS2’s C++ codebase.
  • Simulate Realistic Traffic:
    • Make use of traffic generators such as CBR (Constant Bit Rate) or HTTP-based traffic for simulation.
  1. Document the Project
  • It has detailed reports and documentation of this project such as:
    • Define project goals and problem statement.
    • Make a network topology and sets up.
    • Visualize the simulation outcomes using graphs, tables.
    • Also, provides explanations and references.

These projects concentrate on how to simulate and examine the TCP Protocols Projects with the support of NS2 environment. We are equipped to expand it with additional information on this topic.