How to Implement Fiber Optic Topology in NS2

To implement the fiber optic topology in Network Simulator 2 (ns2), we have to simulate a network which uses high-speed wired links with low latency, commonly imitating fiber optic communication mechanisms. These topologies are categorized by high data transmission rates, low delays and long-distance communication. Due to ns2 lacks particular in-built fiber optic module, we can simulate by setting up the wired links with high bandwidth and low propagation delays.

We offer support for Fiber Optic Topology in NS2 implementation, and you can connect with us at ns2project.com for guidance. Our team is here to provide you with excellent topic assistance, ensuring your projects are completed on time by our skilled developers.

Below, we provide the details on how to implement a fiber optic network topology in NS2:

Steps to Implement Fiber Optic Topology in NS2

  1. Set Up NS2

Make certain that NS2 is installed. If it isn’t installed, you can install it by using the below command on Ubuntu/Linux:

sudo apt-get update

sudo apt-get install ns2

  1. Simulate Fiber Optic Links in NS2

In fiber optic networks:

  • Replicate the speed of fiber optic communication by using high bandwidth links.
  • Use low latency links to simulate the low propagation delays in fiber optic cables.

Example TCL Script for Fiber Optic Topology

In this sample, we will simulate fiber optic topology where four nodes are linked using high-speed fiber optic links. This instance will generate a simple topology where nodes are connected using duplex links that replicate fiber optics with high bandwidth (such as 10Gbps) and low delay (like 2ms).

# Define the simulator

set ns [new Simulator]

# Open trace files for output

set tracefile [open fiber_optic_out.tr w]

set namfile [open fiber_optic_out.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

# Create a wired topology

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

# Position the nodes (for visualization purposes in NAM)

$n0 set X_ 100.0

$n0 set Y_ 300.0

$n1 set X_ 200.0

$n1 set Y_ 300.0

$n2 set X_ 300.0

$n2 set Y_ 300.0

$n3 set X_ 400.0

$n3 set Y_ 300.0

# Create fiber optic links between nodes with high bandwidth and low delay

# Simulating fiber optic with 10Gbps bandwidth and 2ms delay

$ns duplex-link $n0 $n1 10Gb 2ms DropTail

$ns duplex-link $n1 $n2 10Gb 2ms DropTail

$ns duplex-link $n2 $n3 10Gb 2ms DropTail

# Set up traffic (CBR over UDP) from node n0 to node n3

set udp0 [new Agent/UDP]

set null0 [new Agent/Null]

$ns attach-agent $n0 $udp0

$ns attach-agent $n3 $null0

$ns connect $udp0 $null0

# Create CBR (Constant Bit Rate) traffic

set cbr0 [new Application/Traffic/CBR]

$cbr0 set packetSize_ 1500

$cbr0 set interval_ 0.01

$cbr0 attach-agent $udp0

# Start traffic at time 1.0 second

$ns at 1.0 “$cbr0 start”

# Schedule simulation end

$ns at 10.0 “finish”

# Finish procedure to close the simulation and generate output

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam fiber_optic_out.nam &

exit 0

}

# Run the simulation

$ns run

Explanation of the Script:

  1. Node Creation and Positioning:
    • Four nodes (n0, n1, n2, and n3) are designed and located for visual clarity in NAM (Network Animator).
  2. Fiber Optic Links:
    • The links amongst nodes are generated as fiber optic by using high-bandwidth 10Gbps links and low-latency 2ms delays. These parameters simulate the high-speed, low-latency features of fiber optic communication.
  3. Traffic Setup:
    • Use UDP to produce the traffic from n0 to n3. Send packets amongst the nodes at regular pauses by using CBR (Constant Bit Rate) application. The packet size is set to 1500 bytes to imitate large data transmissions often found in fiber optic networks.
  4. Trace and NAM Visualization:
    • The simulation produces trace files (fiber_optic_out.tr) and a NAM file (fiber_optic_out.nam) that can be visualized using NAM.
  1. Run the Simulation

Store the script as fiber_optic_topology.tcl and execute it in NS2:

ns fiber_optic_topology.tcl

Use NAM to see the network by using:

nam fiber_optic_out.nam

Customization:

  1. Expanding the Topology:
    • You can include more nodes and links to develop a larger fiber optic network. Just state more nodes and link them using duplex links with high bandwidth and low delay.
  2. Traffic Patterns:
    • Design extra traffic flows amongst various nodes to replicate several streams of data across the fiber optic network. For instance, you could set up traffic amongst n1 and n3 or between n0 and n2.
  3. Link Parameters:
    • Replicate different variant of fiber optic networks (like higher bandwidth for more modern fiber standards or longer delay for geographically allocated nodes) by modifying the bandwidth and delay.
  4. Packet Sizes and Rates:
    • Vary the packet size and data rate in the CBR traffic generator to reflect various application demands includes streaming video, large file transfers, or low-latency communication.

This process has covered the whole concept which is essential to know before implementing the fiber optic topology like how to set up ns2 environment and how to accomplish the links that should be connected for long-distance communication and so on. We will offer the additional record regarding this topology based on your needs.