How to Start SDN Projects Using NS3

To start a Software-Defined Networking (SDN) project using NS3 has includes configuring a network along with programmable switches and a central SDN controller actively handling traffic flows. NS3’s support is restricted for SDN, however by incorporating NS3 along with SDN simulation tools such as OpenFlow and Mininet, otherwise by utilizing certain components, we can make SDN simulations.

Below is a simplified approach to setting up an SDN project in NS3.

Steps to Start SDN Projects in NS3

  1. Install NS3 and OpenFlow Module
  1. Download and Install NS3 if we haven’t already installed:

git clone https://gitlab.com/nsnam/ns-3-dev.git ns-3

cd ns-3

./waf configure –enable-examples –enable-tests

./waf build

  1. Install OpenFlow Module in NS-3: NS3 contains an OpenFlow module, while it is outdated slightly equated to present executions of SDN. For simple SDN functions, we can even utilize it.
    • OpenFlow is normally incorporated along with NS3 like an extension, and we want to insert the openflow-switch module.
  2. Verify Installation: Execute an OpenFlow instance confirming that the OpenFlow switch module is properly functioning:

./waf –run=openflow-switch

  1. Understand SDN Components in NS3

We will function with following components in an SDN simulation:

  • SDN Controller: It handles the network by installing flow rules within switches.
  • OpenFlow Switches: According to the rules set by the SDN controller, send packets.
  • Host Nodes: Devices or nodes, which transmit or receive traffic.
  • Flow Rules: Direct traffic flows based on the rules set by the controller.
  1. Set Up a Basic SDN Network Topology

A simple SDN topology has host nodes that associated to OpenFlow-enabled switches, handled by a central controller.

Example: Basic SDN Network with an OpenFlow Controller

This instance configures a basic SDN network along with two hosts, one OpenFlow switch, and a simple controller.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/openflow-module.h”

using namespace ns3;

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

CommandLine cmd;

cmd.Parse(argc, argv);

// Create nodes

NodeContainer hosts;

hosts.Create(2); // Two hosts

NodeContainer switches;

switches.Create(1); // One OpenFlow switch

// Set up point-to-point connections

PointToPointHelper pointToPoint;

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

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

// Connect hosts to the switch

NetDeviceContainer hostDevices, switchDevices;

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

NetDeviceContainer link = pointToPoint.Install(hosts.Get(i), switches.Get(0));

hostDevices.Add(link.Get(0));

switchDevices.Add(link.Get(1));

}

// Install OpenFlow on the switch

Ptr<ns3::ofi::OpenFlowSwitchNetDevice> openflowSwitch = CreateObject<ns3::ofi::OpenFlowSwitchNetDevice>();

openflowSwitch->SetNode(switches.Get(0));

switches.Get(0)->AddDevice(openflowSwitch);

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

openflowSwitch->AddSwitchPort(switchDevices.Get(i));

}

// Create an OpenFlow controller

Ptr<ns3::ofi::LearningController> controller = CreateObject<ns3::ofi::LearningController>();

openflowSwitch->SetController(controller);

// Install IP stack

InternetStackHelper internet;

internet.Install(hosts);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer hostInterfaces = address.Assign(hostDevices);

// Set up applications (e.g., TCP or UDP communication between hosts)

uint16_t port = 9;

OnOffHelper clientHelper(“ns3::UdpSocketFactory”, InetSocketAddress(hostInterfaces.GetAddress(1), port));

clientHelper.SetAttribute(“DataRate”, StringValue(“500Kbps”));

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

ApplicationContainer clientApp = clientHelper.Install(hosts.Get(0));

clientApp.Start(Seconds(1.0));

clientApp.Stop(Seconds(10.0));

PacketSinkHelper sinkHelper(“ns3::UdpSocketFactory”, InetSocketAddress(Ipv4Address::GetAny(), port));

ApplicationContainer serverApp = sinkHelper.Install(hosts.Get(1));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

Simulator::Run();

Simulator::Destroy();

return 0;

}

  1. Integrate External SDN Controllers

We replicate a more advanced SDN configuration; to incorporate an external SDN controller such as POX or RYU:

  1. Install a Virtual SDN Controller: Configure a virtual environment including a POX or RYU controller. These controllers interact through the OpenFlow protocol.
  2. Link NS3 to the Controller: Launch a link among NS3 and to utilize the openflow-switch module or external, integration the external controller.

Also, we can deliberate to utilize the Mininet for the SDN configuration and for more complex SDN capabilities, then associating it with NS3 for realistic traffic modeling.

  1. Configure SDN Flow Rules

By the controller, we can set up actively flow rules according to the network state. LearningController performs like a basic controller, however with an external controller we can be executed the custom rules in NS3.

Example of Custom Flow Rules

Depends on traffic type, source-destination pairs, or load balancing strategies, we can describe the rules within an external controller and execute them to the switches.

  1. Set Up Network Traffic

Make traffic among hosts that permitting to monitor how the SDN controller manages the flows utilize applications such as OnOffApplication or BulkSendApplication.

Example:

OnOffHelper onOff(“ns3::TcpSocketFactory”, InetSocketAddress(hostInterfaces.GetAddress(1), port));

onOff.SetAttribute(“DataRate”, StringValue(“500Kbps”));

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

ApplicationContainer onOffApp = onOff.Install(hosts.Get(0));

onOffApp.Start(Seconds(1.0));

onOffApp.Stop(Seconds(10.0));

  1. Collect and Analyze Network Performance Metrics

For SDN projects, general performance parameters contain:

  • Throughput: Estimate the data rate through diverse flows.
  • Latency: We can observe delay among hosts.
  • Flow Completion Time: Monitor the time taken to start and finish flows.
  • Packet Loss: We can see packet delivery identifying the network congestion or path issues.

Gather performance parameters to utilize FlowMonitor:

FlowMonitorHelper flowmon;

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

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

  1. Visualize Network Flows and Results
  • NetAnim: Envision SDN flows that contain switch and controller communications utilizing NetAnim.
  • Trace Files: Examine trace files knowing the flow establishment and then we observe the traffic flow.
  • Packet Capture: Seize packets to confirm flow rules and network performance.
  1. Experiment with Advanced SDN Scenarios

In NS3, after we become skilled at basic SDN concepts then test more complex situations:

  • Dynamic Flow Management: Execute the custom flow management strategies within the controller managing network congestion.
  • Load Balancing: Deliver traffic over several paths avoiding the congestion.
  • Network Security: We can replicate and experiment the replies to attacks like DDoS and then discover security solutions within the SDN controller.

We elucidated the stepwise methodology with relevant instance snippets for SDN Projects, initiated and analysed through NS3 simulation tool. We can offer further insights and specifics as needed.

For further assistance with SDN projects utilizing NS3 in your region, you may depend on our specialists. Kindly reach out to phdprojects.org, and we will help you attain optimal results. We manage SDN simulation tools, including OpenFlow and Mininet, so please provide us with your project details for additional support.