How to Start Bus Star Hybrid Topology Projects Using NS3

To start a Bus-Star Hybrid Topology in NS3, it integrates the bus and star topologies in which nodes are connected via star sub-networks associated using a bus network. This structure is generally used in enterprise networks in which each department (star) associates to a backbone (bus). Below is a step-by-step procedure to get started:

Steps to Start Bus-Star Hybrid Topology Project in NS3

Step 1: Set Up NS3

  1. Install NS3:
    • Go to NS3 website to download NS3.
    • Build NS3:

./waf configure

./waf build

  1. Verify Installation: Confirm NS3 to utilize a simple example:

./waf –run scratch/my_first

Step 2: Understand Bus-Star Hybrid Topology

  • Characteristics:
    • This topology integrates the bus topology (linear backbone) including star topology (local networks).
    • It minimizes wiring whereas sustaining the structured connectivity.
    • For instance, every single star network contains a hub connected to the backbone.

Step 3: Plan the Topology

  1. Define the structure:
    • We can describe the volume of star networks like 3 stars.
    • Number of nodes for each star such as 4 nodes each.
    • Backbone to associate the hubs of each star.
  2. Set simulation goals:
    • We need to estimate the throughput, delay, and fault tolerance.
    • Replicate an inter-star interaction through the backbone.

Step 4: Set Up the Bus-Star Hybrid Topology

  1. Create Nodes: Describe nodes for the stars and backbone.

NodeContainer hubs, stars, backbone;

uint32_t numStars = 3;

uint32_t nodesPerStar = 4;

// Create hubs for each star

hubs.Create(numStars);

// Create nodes for each star

stars.Create(numStars * nodesPerStar);

// Create nodes for the backbone

backbone.Add(hubs);

  1. Set Up Star Networks: In each star, associate nodes to its hub.

PointToPointHelper p2pStar;

p2pStar.SetDeviceAttribute(“DataRate”, StringValue(“1Gbps”));

p2pStar.SetChannelAttribute(“Delay”, StringValue(“2ms”));

NetDeviceContainer starDevices;

for (uint32_t i = 0; i < numStars; ++i) {

for (uint32_t j = 0; j < nodesPerStar; ++j) {

uint32_t nodeIndex = i * nodesPerStar + j;

NetDeviceContainer link = p2pStar.Install(hubs.Get(i), stars.Get(nodeIndex));

starDevices.Add(link);

}

}

  1. Set Up the Backbone (Bus): Associate hubs to utilize a point-to-point or shared channel.

PointToPointHelper p2pBus;

p2pBus.SetDeviceAttribute(“DataRate”, StringValue(“10Gbps”));

p2pBus.SetChannelAttribute(“Delay”, StringValue(“1ms”));

NetDeviceContainer busDevices;

for (uint32_t i = 0; i < numStars – 1; ++i) {

NetDeviceContainer link = p2pBus.Install(hubs.Get(i), hubs.Get(i + 1));

busDevices.Add(link);

}

  1. Install Internet Stack: We can insert the Internet stack to every node and then allocate an IP addresses.

InternetStackHelper stack;

stack.Install(hubs);

stack.Install(stars);

Ipv4AddressHelper address;

// Assign IP addresses to star devices

address.SetBase(“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer starInterfaces = address.Assign(starDevices);

// Assign IP addresses to bus devices

address.SetBase(“10.2.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer busInterfaces = address.Assign(busDevices);

Step 5: Simulate Traffic

  1. Set Up Applications: Describe the traffic among nodes within diverse stars.
    • UDP Echo Example:

UdpEchoServerHelper echoServer(9); // Port 9

ApplicationContainer serverApp = echoServer.Install(stars.Get(0)); // Server on Node 0 of Star 1

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(starInterfaces.GetAddress(0), 9); // Server’s IP

echoClient.SetAttribute(“MaxPackets”, UintegerValue(10));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));

echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));

ApplicationContainer clientApp = echoClient.Install(stars.Get(nodesPerStar)); // Client on Node 0 of Star 2

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

  1. Use Flow Monitor: Estimate the metrics like throughput, delay, and packet loss to utilize Flow Monitor.

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

monitor->SerializeToXmlFile(“bus_star_hybrid_flowmon.xml”, true, true);

Step 6: Run and Analyze

  1. Run the Simulation:

Simulator::Run();

Simulator::Destroy();

  1. Enable Packet Capture: We can store .pcap files for traffic investigation.

p2pBus.EnablePcapAll(“bus_star_hybrid_topology”);

  1. Analyze Results: Measure the performance outcomes with the help of Flow Monitor and packet traces.

Example: Minimal NS3 Script for Bus-Star Hybrid Topology

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

#include “ns3/flow-monitor-module.h”

using namespace ns3;

int main(int argc, char *argv[]) {

uint32_t numStars = 3;

uint32_t nodesPerStar = 4;

// Create hubs and nodes

NodeContainer hubs, stars;

hubs.Create(numStars);

stars.Create(numStars * nodesPerStar);

// Configure point-to-point links for stars

PointToPointHelper p2pStar;

p2pStar.SetDeviceAttribute(“DataRate”, StringValue(“1Gbps”));

p2pStar.SetChannelAttribute(“Delay”, StringValue(“2ms”));

NetDeviceContainer starDevices;

for (uint32_t i = 0; i < numStars; ++i) {

for (uint32_t j = 0; j < nodesPerStar; ++j) {

uint32_t nodeIndex = i * nodesPerStar + j;

NetDeviceContainer link = p2pStar.Install(hubs.Get(i), stars.Get(nodeIndex));

starDevices.Add(link);

}

}

// Configure point-to-point links for the backbone (bus)

PointToPointHelper p2pBus;

p2pBus.SetDeviceAttribute(“DataRate”, StringValue(“10Gbps”));

p2pBus.SetChannelAttribute(“Delay”, StringValue(“1ms”));

NetDeviceContainer busDevices;

for (uint32_t i = 0; i < numStars – 1; ++i) {

NetDeviceContainer link = p2pBus.Install(hubs.Get(i), hubs.Get(i + 1));

busDevices.Add(link);

}

// Install Internet stack

InternetStackHelper stack;

stack.Install(hubs);

stack.Install(stars);

Ipv4AddressHelper address;

// Assign IP addresses

address.SetBase(“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer starInterfaces = address.Assign(starDevices);

address.SetBase(“10.2.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer busInterfaces = address.Assign(busDevices);

// Set up UDP echo server and client

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApp = echoServer.Install(stars.Get(0));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(starInterfaces.GetAddress(0), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(10));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(1.0)));

echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));

ApplicationContainer clientApp = echoClient.Install(stars.Get(nodesPerStar));

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

// Enable Flow Monitor

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

monitor->SerializeToXmlFile(“bus_star_hybrid_flowmon.xml”, true, true);

// Enable packet capture

p2pBus.EnablePcapAll(“bus_star_hybrid_topology”);

// Run simulation

Simulator::Run();

Simulator::Destroy();

These projects focus on how to set up and simulate the Bus-Star Hybrid Topology projects and how to analyse the results using NS3 tools through above presented structured approach. If you have any idea to expand it further, we will also guide you.

phdprojects.org provides a comprehensive guide on how to initiate and simulate Bus-Star Hybrid Topology Projects using the NS3 tool. Our team of developers is ready to assist you in enhancing your project’s performance. Just share your project details with us, and we will offer you the best support possible.