How to Start Fiber Optic Topology Projects Using NS2

To start a Fiber Optic Topology using NS2 (Network Simulator 2), we will need to design a high-speed optical network in which nodes interact through the fiber-optic links. Fiber optic topologies are typically utilised for replicating the high-capacity data transmission within backbone or long-distance networks. NS2 doesn’t direct support fiber-optic links, but we want to replicate them by means of designing fiber optic cables like high-bandwidth, low-latency links among the nodes.

Below is a comprehensive method to get started with your Fiber Optic Topology project in NS2:

Steps to Start Fiber Optic Topology in NS2

  1. Understand Fiber Optic Topology
  • Structure:
    • Fiber optic networks normally contain high-capacity, long-distance interaction connections among the nodes such as routers, switches.
    • Fiber-optic links contains a very high bandwidth which is normally includes numerous Gbps and low latency, and the signal degrades across long distances which needs deliberation of signal amplification or regeneration.
  • Applications:
    • Long-distance interaction networks.
    • High-speed data centers.
    • Backbone networks for internet service providers (ISPs).
  1. Set Up NS2
  1. Install NS2: If we don’t install NS2 then we can follow these command:

sudo apt-get install ns2

  1. Verify Installation: Execute a simple test, making sure that NS2 is properly configured:

ns example.tcl

  1. Define Fiber Optic Links in NS2
  • High-Bandwidth Links: Fiber optic connections can be replicated by way of setting too high bandwidth values for the links.
  • Low Latency: We can set too low latency indicating its high-speed nature for the fiber optic links.
  • No Interference: Replicate the optimal connections by eliminating the interference factors which is normally determined in wireless or copper cable networks.
  1. TCL Script for Fiber Optic Topology

Here’s an instance of a Fiber Optic Topology in NS2:

TCL Script Example

# Initialize NS2 Simulator

set ns [new Simulator]

set tracefile [open fiber_optic_topology.tr w]

$ns trace-all $tracefile

# Define the number of nodes and fiber optic links

set num_nodes 4

# Create nodes (routers/switches)

for {set i 0} {$i < $num_nodes} {incr i} {

set node($i) [$ns node]

}

# Create high-bandwidth, low-latency fiber optic links

# Fiber optic links typically have high bandwidth (e.g., 10Gbps) and low latency (e.g., 1ms)

for {set i 0} {$i < [expr $num_nodes – 1]} {incr i} {

set next [expr $i + 1]

$ns duplex-link $node($i) $node($next) 10Gb 1ms DropTail

}

# Attach agents for traffic simulation

# Example: Traffic from Node 0 to Node 3

set tcp0 [new Agent/TCP]

$ns attach-agent $node(0) $tcp0

set sink0 [new Agent/TCPSink]

$ns attach-agent $node(3) $sink0

$ns connect $tcp0 $sink0

# Add a traffic generator (FTP)

set ftp [new Application/FTP]

$ftp attach-agent $tcp0

# Start traffic

$ns at 1.0 “$ftp start”

# End simulation

$ns at 5.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

$ns run

  1. Key Features to Simulate
  1. High-Speed Communication:
    • Fiber optic links provide high bandwidth such as 10Gbps or 100Gbps and very low latency.
    • Mimic bidirectional interaction including too high bandwidth and low latency with the support of duplex-link.
  2. Traffic Flow:
    • Replicate data transmission across the fiber optic links to utilise agents such as Agent/TCP, Agent/UDP.
  3. Performance Metrics:
    • Throughput: Estimate the rate of data transfer through the fiber optic links.
    • Latency: Examine delays among the nodes that are associated by fiber.
    • Packet Loss: Measure the reliability and capacity of network.
  1. Analyze the Trace File
  • When simulation is executed then we can examine the trace file as fiber_optic_topology.tr.
  • Obtain certain performance parameters such as throughput or packet loss:
    • Throughput:

grep “tcp” fiber_optic_topology.tr > throughput.log

    • Dropped Packets:

grep “drop” fiber_optic_topology.tr > dropped_packets.log

  1. Visualize Results

For envisioning the data, we need to leverage Gnuplot or another graphing tool:

  1. Throughput Graph:

set title “Fiber Optic Topology Throughput”

plot “throughput.log” using 1:2 with lines title “Throughput”

  1. Latency Graph:
    • Envision measurements of latency through the fiber optic links.
  1. Extend the Simulation
  2. Simulate Larger Networks
  • We will need to integrate additional nodes and fiber optic links for making a larger fiber optic network:

$ns duplex-link $node(3) $node(4) 10Gb 1ms DropTail

  1. Introduce Faults or Failure Scenarios
  • Experiment the link failures or congestion effect:

$ns at 2.5 “$ns reset-links $node(2) $node(3)”

  1. Different Routing Protocols
  • Replicate various routing protocols like OSPF, BGP to handle the large-scale fiber optic networks.
  1. Simulate QoS or Traffic Shaping
  • Incorporate Quality of Service (QoS) aspects to give precedence for specific kinds of traffic like voice or video over fiber.
  1. Modify NS2 Core for Advanced Features
  1. Custom Fiber Optic Parameters:
    • We can alter NS2 core to launch certain fiber optic cables features in terms of signal degradation, noise, or bandwidth throttling over distance.
  2. Traffic Management:
    • Execute the traffic management mechanisms for replicating congestion control, priority traffic, and flow control.

Tools and Resources

  • Wireshark: Examine the captured packets and network flow with the support of Wireshark.
  • Gnuplot: It is designed for envisioning performance parameters such as throughput, latency, and packet loss to obtain clear knowledge of network performance.
  • NS2 Documentation: NS2’s official documentation will support to set up more advanced simulation.

Enhancements

  • Simulate Long-Distance Fiber Optic Links: It contains longer-distance connections for replicating signal attenuation and the signal regeneration requirements.
  • Add Error Modeling: Mimic errors to experiment the network robustness on the fiber-optic link.
  • Compare Fiber Optic with Other Networks: We can equate the performance of fiber optic links with other links of interaction media like copper cables or wireless networks.

From this approach, we can thoroughly understand how to simulate, analyse and visualize the Fiber Optic Topology projects and we also know about the extension of this simulation using NS2 environment. If you have any doubts about this process, we will help you.