How to Start Logical Topology Projects Using NS3

To Simulate the Logical Topology characteristics the virtual connections among nodes on top of a physical topology. The Logical topology projects permits to we simulate the analysis for abstract architecture of a network independent of its physical infrastructure.

Steps to Start Logical Topology Projects Using NS3

Step 1: Set Up NS-3

  1. Install NS-3:
    • Download NS-3.
    • Observe the installation Process.
  2. Verify Installation: Processing the basic script to verify the installation:

./waf –run scratch/my_first

Step 2: Understand Logical Topology

  • Logical Topology:
    • A network setting which abstracts to the physical connections.
    • General use cases:
      • Software-defined networking (SDN).
      • Content delivery networks (CDNs).
      • Logical layer of peer-to-peer networks.

Step 3: Plan the Topology

  1. Define the physical network:
    • Sample: Mesh topology has contained five nodes.
  2. Define the logical network:
    • The Logical connections are independent of the physical layer.
  3. Set simulation goals:
    • Replicate the virtualized network traffic.
    • Calculate the throughput, delay, and jitter.

Step 4: Set Up the Physical Topology

  1. Create Physical Nodes: State the nodes for the physical network.

NodeContainer physicalNodes;

uint32_t numPhysicalNodes = 5;

physicalNodes.Create(numPhysicalNodes);

  1. Set Up Point-to-Point Links: Utilized their PointToPointHelper we describe the physical connections.

PointToPointHelper p2p;

p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));

  1. Connect Physical Nodes: Build a mesh or custom topology for the physical network.

NetDeviceContainer physicalDevices;

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

for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {

NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));

physicalDevices.Add(link);

}

}

  1. Install Internet Stack: Enhance the Internet stack to all physical nodes.

InternetStackHelper stack;

stack.Install(physicalNodes);

  1. Assign IP Addresses: Allocate the unique IP addresses to every physical link.

Ipv4AddressHelper address;

uint32_t subnetIndex = 1;

for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {

std::ostringstream subnet;

subnet << “10.1.” << subnetIndex++ << “.0”;

address.SetBase(subnet.str().c_str(), “255.255.255.0”);

address.Assign(physicalDevices.Get(i));

}

Step 5: Set Up the Logical Topology

  1. Define Logical Links: Specify the logical links among nodes.

std::vector<std::pair<uint32_t, uint32_t>> logicalLinks = {

{0, 3}, {1, 4}, {2, 3}, {0, 4}

};

  1. Create Virtual Connections: Utilized their UDP sockets we create virtual communication over the physical network.

for (auto &link : logicalLinks) {

Ptr<Node> src = physicalNodes.Get(link.first);

Ptr<Node> dest = physicalNodes.Get(link.second);

// Source application

OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));

onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));

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

ApplicationContainer srcApp = onOff.Install(src);

srcApp.Start(Seconds(1.0));

srcApp.Stop(Seconds(10.0));

 

// Sink application

PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));

ApplicationContainer sinkApp = sink.Install(dest);

sinkApp.Start(Seconds(1.0));

sinkApp.Stop(Seconds(10.0));

}

Step 6: Run and Analyze

  1. Run the Simulation:

Simulator::Run();

Simulator::Destroy();

  1. Enable Packet Capture: Save .pcap files for traffic analysis.

p2p.EnablePcapAll(“logical_topology”);

  1. Trace Logs: Ensure the logging for debugging:

export NS_LOG=”UdpClientApplication=level_all|prefix_func”

./waf –run scratch/logical_topology

Example: Minimal NS-3 Script for Logical 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”

using namespace ns3;

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

uint32_t numPhysicalNodes = 5;

// Create physical nodes

NodeContainer physicalNodes;

physicalNodes.Create(numPhysicalNodes);

// Set up Point-to-Point links

PointToPointHelper p2p;

p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));

// Connect physical nodes in a mesh

NetDeviceContainer physicalDevices;

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

for (uint32_t j = i + 1; j < numPhysicalNodes; ++j) {

NetDeviceContainer link = p2p.Install(physicalNodes.Get(i), physicalNodes.Get(j));

physicalDevices.Add(link);

}

}

// Install Internet stack

InternetStackHelper stack;

stack.Install(physicalNodes);

// Assign IP addresses

Ipv4AddressHelper address;

uint32_t subnetIndex = 1;

for (uint32_t i = 0; i < physicalDevices.GetN(); ++i) {

std::ostringstream subnet;

subnet << “10.1.” << subnetIndex++ << “.0”;

address.SetBase(subnet.str().c_str(), “255.255.255.0”);

address.Assign(physicalDevices.Get(i));

}

// Define logical links

std::vector<std::pair<uint32_t, uint32_t>> logicalLinks = {

{0, 3}, {1, 4}, {2, 3}, {0, 4}

};

// Create logical topology applications

for (auto &link : logicalLinks) {

Ptr<Node> src = physicalNodes.Get(link.first);

Ptr<Node> dest = physicalNodes.Get(link.second);

// Source application

OnOffHelper onOff(“ns3::UdpSocketFactory”, InetSocketAddress(dest->GetObject<Ipv4>()->GetAddress(1, 0).GetLocal(), 9));

onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));

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

ApplicationContainer srcApp = onOff.Install(src);

srcApp.Start(Seconds(1.0));

srcApp.Stop(Seconds(10.0));

// Sink application

PacketSinkHelper sink(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), 9));

ApplicationContainer sinkApp = sink.Install(dest);

sinkApp.Start(Seconds(1.0));

sinkApp.Stop(Seconds(10.0));

}

// Enable packet capture

p2p.EnablePcapAll(“logical_topology”);

// Run the simulation

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 7: Compile and Run

  1. Save the script as logical_topology.cc.
  2. We compile and run it:

./waf –run logical_topology

Step 8: Enhance the Simulation

  • Experiment with Dynamic Logical Links:
    • Enhance or Eliminate the connection during replication.
  • Analyze Performance:
    • Calculate the throughput, delay, jitter, and packet loss.
  • Simulate Real-World Scenarios:
    • Utilized their logical topologies we replicate the SDN or virtualized networks.
  • Visualize:
    • Utilized their NetAnim we display the physical and logical topologies.

Next Steps

  • Scale Up:
    • Logical links and increase the number of nodes.
  • Test Different Traffic Models:
    • Replicate the TCP, FTP, or HTTP traffic over the logical topology.
  • Incorporate Failures:
    • Replicate the node or connection failures we estimate the fault tolerance.

As we saw in this process, it will help you to set up the simulation network, to fine-tune the simulator and to establish the Logical Topology in the NS3 by essential topology that presents some samples. If needed, we can help you with another approach.

At phdprojects.org, we are dedicated to supporting you with Logical Topology Projects Utilizing NS3, providing tailored assistance whenever necessary. Our knowledge encompasses guidance on Logical Topology designed to align with your unique research needs. Reach out to phdprojects.org for research support and a clear overview. We offer detailed, step-by-step instructions for your research, ensuring you can rely on us for cutting-edge and pertinent topics.