How to Start Open Shortest Path First Projects Using NS3

To start an Open Shortest Path First (OSPF) project using NS3 encompasses to replicate or execute the OSPF that is a link-state routing protocol generally utilized within IP networks. While NS3 doesn’t directly support an OSPF execution then we will either require enhancing a custom OSPF protocol or to combine an external OSPF execution such as from Quagga or FRRouting.

We will guide you on how to start the OSPF Projects using NS3 tool:

Steps to Start OSPF Projects in NS3

  1. Understand OSPF and NS3
  • What is OSPF?
    • OSPF is a link-state routing protocol, which determines the shortest path to utilize the Dijkstra algorithm.
    • Key Features:
      • Hierarchical design including areas.
      • Fast convergence.
      • Make use of Link-State Advertisements (LSAs) for topology data.
  • NS-3 Capabilities:
    • NS3 environments utilizes static and dynamic routing such as RIP however OSPF wants to be manually executed or incorporated through an external tool.
  1. Set Up NS3
  • Install NS3:
    • Go to nsnam.org to download and install NS3.
  • Verify Installation:

./waf –run scratch/test-example

  • Required Modules:
    • internet: It supports for IPv4 routing and IP stack.
    • point-to-point: For wired network simulation.
    • traffic-control: For QoS tests (optional).
  1. Plan Your OSPF Project
  • Project Objectives:
    • To replicate the OSPF routing behavior.
    • Examine performance parameters such as convergence time, routing overhead, and path optimization.
  • Possible Scenarios:
    • In a single area, we mimic OSPF.
    • Experiment OSPF convergence in link failure.
    • For hierarchical routing, we replicate multi-area OSPF.
  • Metrics to Measure:
    • We estimate the indicators such as routing convergence time, packet delivery ratio, and routing overhead.
  1. Option 1: Implement OSPF in NS3
  • Extend the Ipv4RoutingProtocol Class:
    • OSPF includes to make and sustaining the link-state databases (LSDBs) and computing shortest paths.
    • Key Methods to Implement:
      • RouteInput(): Manage the incoming packets.
      • RouteOutput(): We discover the next hop for outgoing packets.
      • LinkStateAdvertisement(): We swap the LSAs among routers.
    • Algorithm:
      • Determine shortest paths utilising Dijkstra algorithm depends on the LSDB.
  • Example: Setting Up Nodes and Links

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

using namespace ns3;

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

NodeContainer nodes;

nodes.Create(4);

PointToPointHelper p2p;

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

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

NetDeviceContainer devices1 = p2p.Install(nodes.Get(0), nodes.Get(1));

NetDeviceContainer devices2 = p2p.Install(nodes.Get(1), nodes.Get(2));

NetDeviceContainer devices3 = p2p.Install(nodes.Get(2), nodes.Get(3));

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper ipv4;

ipv4.SetBase(“10.1.1.0”, “255.255.255.0”);

ipv4.Assign(devices1);

ipv4.SetBase(“10.1.2.0”, “255.255.255.0”);

ipv4.Assign(devices2);

ipv4.SetBase(“10.1.3.0”, “255.255.255.0”);

ipv4.Assign(devices3);

// Custom OSPF logic here (e.g., adding routes dynamically)

Simulator::Run();

Simulator::Destroy();

return 0;

}

  1. Option 2: Integrate External OSPF Tools
  • Use Quagga/FRRouting:
    • Utilize Direct Code Execution (DCE) to combine a full-featured OSPF execution to NS3.
    • Steps:
      1. Initially, we install the ns-3-dce module.
      2. Set up Quagga or FRRouting, allowing OSPF.
      3. Replicate the nodes within NS3 whereas executing Quagga/FRR for OSPF routing.
      • Example: DCE including Quagga Documentation
  • Advantages:
    • Completely functional OSPF executions without recreating the wheel.
    • Simpler to set up and examine.
  1. Test and Debug
  • Enable Logging:

export NS_LOG=Ipv4RoutingProtocol=level_all

./waf –run scratch/ospf-project

  • Routing Table Inspection:
    • Configure OSPF logic to examine the routing tables:

Ptr<Ipv4> ipv4 = nodes.Get(0)->GetObject<Ipv4>();

ipv4->GetRoutingProtocol()->Print(std::cout);

  • Packet Flow Analysis:
    • Inspect control and data packets to utilize PCAP tracing:

p2p.EnablePcapAll(“ospf”);

  1. Evaluate OSPF Performance
  • Metrics to Measure:
    • After a topology change, we estimate the convergence time.
    • Compute routing overhead (control traffic).
    • Then, we estimate the end-to-end delay and throughput.
  • Use FlowMonitor:
    • We need to accumulate and examine the performance parameters:

FlowMonitorHelper flowMonitor;

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

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

  1. Advanced Features
  • Multi-Area OSPF:
    • We can replicate and measure the hierarchical OSPF including several areas.
  • QoS Integration:
    • Test with OSPF traffic engineering extensions.
  • Failure Recovery:
    • Experiment the capability of OSPF to manage the link or node failures.

We had successfully conducted the simulation procedure to start and analyse the Open Shortest Path First Projects within NS3 environment. If you have any query on above process we will also clear it.

For your Open Shortest Path First projects utilizing the NS3 tool, trust the skilled team at phdprojects.org to support you throughout every stage. Take advantage of our tailored assistance to achieve the best results and meet deadlines. Our developers are ready to enhance your project performance and provide guidance on Quagga or FR Routing, so feel free to reach out for more information.