How to Start Transport Layer Projects Using NS2

To start a Transport Layer project in NS2 (Network Simulator 2) that addressing primary protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol). These protocols support to handle the end-to-end interaction, congestion control, reliability, and flow control. Following is a basic approach to start and simulate the Transport Layer Projects in NS2:

Steps to Start Transport Layer Projects in NS2

  1. Understand Transport Layer in NS2
  • Protocols at Transport Layer:
    • TCP Variants: Reno, NewReno, Vegas, Tahoe, and so on.
    • UDP: It is a lightweight protocol devoid of reliability or congestion control.
  • Project Goals:
    • Examine the performance of TCP/UDP in diverse network conditions.
    • Equate the TCP variants.
    • Create and experiment the custom transport protocols.
  1. Set Up NS2
  • Install NS2:
    • We can download and set up NS2.35 on the system.
  • Verify Installation:
    • Confirm the installation by executing a simple example Tcl script:

ns example.tcl

  1. Choose a Focus for Your Project
  • TCP-Based Projects:
    • Congestion control analysis.
    • Equate the performance of TCP variants like Reno vs. Vegas.
    • TCP performance in high traffic or lossy networks.
  • UDP-Based Projects:
    • Examine the metrics such as latency and jitter in UDP.
    • Focus on UDP within real-time usages like video streaming.
  • Custom Protocol Development:
    • Execute a new transport protocol or fine-tune existing ones for enhancement.
  1. Write a Simulation Script

Make a Tcl script in NS2 for replicating a network including TCP or UDP agents.

Example Script: TCP vs. UDP Performance

# Initialize the simulator

set ns [new Simulator]

# Define trace and NAM output files

set tracefile [open transport_layer.tr w]

$ns trace-all $tracefile

set namfile [open transport_layer.nam w]

$ns namtrace-all $namfile

# Create nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

# Create duplex links

$ns duplex-link $n0 $n1 10Mb 10ms DropTail

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

$ns duplex-link $n2 $n3 10Mb 10ms DropTail

# Configure TCP agent

set tcp [new Agent/TCP]

$ns attach-agent $n0 $tcp

set sink [new Agent/TCPSink]

$ns attach-agent $n3 $sink

$ns connect $tcp $sink

# Configure UDP agent

set udp [new Agent/UDP]

$ns attach-agent $n1 $udp

set null [new Agent/Null]

$ns attach-agent $n2 $null

$ns connect $udp $null

# Add FTP application over TCP

set ftp [new Application/FTP]

$ftp attach-agent $tcp

$ns at 1.0 “$ftp start”

$ns at 5.0 “$ftp stop”

# Add CBR traffic over UDP

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ 512

$cbr set interval_ 0.05

$ns at 2.0 “$cbr start”

$ns at 6.0 “$cbr stop”

# Finish the simulation

$ns at 10.0 “finish”

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam transport_layer.nam &

exit 0

}

# Run the simulation

$ns run

  1. Run the Simulation
  • We can execute the simulation tcl script as transport_layer.tcl.
  • Then run the simulation using NS2:

ns transport_layer.tcl

  • Outputs:
    • Trace File (transport_layer.tr): It helps to record all simulation events.
    • NAM File (transport_layer.nam): To envision the network using NAM (Network Animator).
  1. Analyze Results
  • Trace File Analysis:
    • We need to obtain the performance parameters to leverage AWK, Python, or MATLAB tools for analysis in trace file:
      • Throughput: Compute the total data which are transmitted for each unit time.
      • Latency: Measure the average time undergone by packets.
      • Packet Loss: Estimate packets that are dropped within the network.
      • Jitter: Difference in packet delay for UDP traffic.
  • NAM Visualization:
    • Monitor the packet flows, congestion, and node communication to utilize NAM files for visualization.
  1. Experiment with Different Scenarios
  • Congestion Control:
    • Launch traffic congestion control and then estimate the response of TCP.
  • Packet Loss:
    • Replicate the lossy connections for estimating the TCP retransmissions or performance of UDP.
  • Traffic Types:
    • Alter traffic models like bursty vs. continuous to experiment the behaviour of protocol.
  1. Enhance the Project
  • TCP Variants:
    • Experiment and equate the diverse TCP executions using its variants:

set tcp [new Agent/TCP/Reno]

set tcp [new Agent/TCP/Vegas]

  • Custom Protocol Development:
    • Fine-tune execution of TCP within C++ for sample tcp.cc, tcp.h.
    • Add new protocol in the NS2 simulation.
  • QoS Analysis:
    • Give precedence to particular traffic types for replicating the Quality of Service (QoS) metrics.
  1. Document the Results
  • Metrics:
    • We can contain performance parameters such as throughput, latency, jitter, and packet loss for analysis.
  • Graphs:
    • Envision the performance parameters with the support of Gnuplot, MATLAB, or Python tools.
  • Report:
    • Record the simulation configuration, scenarios, and conclusions.
  1. Advanced Project Ideas
  • Congestion Control Algorithms:
    • Create or experiment the new congestion control protocols.
  • Multipath TCP:
    • We will mimic TCP through numerous network routes for enhancing the reliability.
  • UDP in Real-Time Applications:
    • Examine the performance of UDP in real-world applications like video or voice streaming.
  • Energy Efficiency:
    • Focus on transport protocols within power-constrained networks like IoT or WSN for energy effectiveness.

Here, we clearly discussed about the Transport Layer Projects using common simulation approaches with coding snippets, which were effectively simulated and enhanced using NS2 simulation tool. Also we elaborate further information regarding this project as per your needs.