How to Implement SDN in OMNeT++

To implement the Software Defined Networking (SDN) in OMNeT++ needs an environment has simulated which contains SDN controllers, switches, and hosts, stating the network models, and executing SDN-specific protocols. We can use the INET framework to model the network components and the OpenFlow protocol for SDN functionalities. Follow the procedure below to implement the SDN in OMNeT++:

Step-by-Step Implementation:

Step 1: Install OMNeT++ and INET Framework

1. Download OMNeT++:
   • Get the latest version of the OMNeT++.
2. Install OMNeT++:
   • Follow the installation details about what fits the operating system.
3. Download and Install INET Framework:
   • The INET framework offers models for internet protocols and is commonly used with OMNeT++.
   • Install the INET framework on your system.

Step 2: Set Up Your Project

1. Create a New OMNeT++ Project:
   • Open the OMNeT++ IDE.
   • Go to File -> New -> OMNeT++ Project.
   • Enter a project name and select the choose options.
2. Set Up Directory Structure:
   • Make sure that the project contains essential like src for source files and simulations for NED files and configuration.
3. Add INET to Your Project:
   • Right-click on project in the Project Explorer.
   • Select Properties -> Project References.
   • Check the box for INET.

Step 3: Define SDN Network Models Using NED

1. Create NED Files:
   • Create a new NED file (e.g., SDNNetwork.ned) in the src directory.
   • In NED file, determine the network topology. Here’s a simple example:

package sdn;

import inet.node.inet.StandardHost;

import inet.node.ethernet.EtherSwitch;

import inet.node.ethernet.EtherHost;

import inet.networklayer.configurator.ipv4.Ipv4NetworkConfigurator;

network SDNNetwork

{

parameters:

int numHosts = default(4);

int numSwitches = default(2);

submodules:

configurator: Ipv4NetworkConfigurator {

@display(“p=100,100”);

}

controller: StandardHost {

@display(“p=200,100”);

}

switch[numSwitches]: EtherSwitch {

@display(“p=300,100+100*i”);

}

host[numHosts]: EtherHost {

@display(“p=400,100+100*i”);

}

connections allowunconnected:

for i=0..numSwitches-1 {

for j=0..numHosts-1 {

host[j].ethg++ <–> Eth100M <–> switch[i].ethg++;

}

controller.ethg++ <–> Eth100M <–> switch[i].ethg++;

}

}

Step 4: Implement SDN Controller Logic

1. Create C++ Modules for the SDN Controller:
   • In the src directory, create a new C++ class (for example: SDNController.cc).
   • Has the essential OMNeT++ headers and define SDN controller logic.
2. SDN Controller Implementation:

#include <omnetpp.h>

#include “inet/applications/base/ApplicationBase.h”

#include “inet/applications/tcpapp/TcpBasicClientApp.h”

#include “inet/applications/tcpapp/TcpServerHostApp.h”

#include “inet/common/packet/Packet.h”

#include “inet/networklayer/common/L3AddressResolver.h”

#include “inet/networklayer/contract/ipv4/Ipv4Address.h”

#include “inet/networklayer/contract/IL3AddressType.h”

#include “inet/linklayer/ethernet/switch/MacRelayUnit.h”

using namespace omnetpp;

using namespace inet;

class SDNController : public ApplicationBase

{

protected:

virtual void initialize(int stage) override;

virtual void handleMessageWhenUp(cMessage *msg) override;

void handlePacket(Packet *pkt);

void configureSwitch(cModule *switchModule);

 

cMessage *configEvent = nullptr;

};

Define_Module(SDNController);

void SDNController::initialize(int stage)

{

ApplicationBase::initialize(stage);

if (stage == INITSTAGE_LOCAL) {

configEvent = new cMessage(“configSwitch”);

scheduleAt(simTime() + par(“configStartTime”), configEvent);

}

}

void SDNController::handleMessageWhenUp(cMessage *msg)

{

if (msg == configEvent) {

for (cModule::SubmoduleIterator it(getSystemModule()); !it.end(); ++it) {

cModule *submodule = *it;

if (strstr(submodule->getName(), “switch”)) {

configureSwitch(submodule);

}

}

delete configEvent;

} else {

Packet *pkt = check_and_cast<Packet *>(msg);

handlePacket(pkt);

}

}

void SDNController::configureSwitch(cModule *switchModule)

{

// Implement switch configuration logic (e.g., flow table setup)

EV << “Configuring switch: ” << switchModule->getFullPath() << endl;

}

void SDNController::handlePacket(Packet *pkt)

{

// Handle received packets (e.g., process control messages)

EV << “Received packet: ” << pkt->getName() << endl;

delete pkt;

}

Step 5: Implement Switch Logic (if needed)

If we need to implement custom switch logic, we can extend the MacRelayUnit module provided by INET.

1. Create C++ Modules for the SDN Switch:
   • Create a new C++ class (for instance: SDNSwitch.cc) in the src directory.
   • Contains essential OMNeT++ headers and define SDN switch logic.
2. SDN Switch Implementation:

#include <omnetpp.h>

#include “inet/linklayer/ethernet/switch/MacRelayUnit.h”

#include “inet/linklayer/ethernet/EtherFrame_m.h”

using namespace omnetpp;

using namespace inet;

class SDNSwitch : public MacRelayUnit

{

protected:

virtual void initialize() override;

virtual void handleAndDispatchFrame(Packet *packet, int inputport) override;

};

Define_Module(SDNSwitch);

void SDNSwitch::initialize()

{

MacRelayUnit::initialize();

// Additional initialization if needed

}

void SDNSwitch::handleAndDispatchFrame(Packet *packet, int inputport)

{

// Implement custom forwarding logic

EV << “Handling frame in SDN switch: ” << packet->getName() << endl;

MacRelayUnit::handleAndDispatchFrame(packet, inputport);

}

Step 6: Configure Simulation Parameters

1. Create omnetpp.ini:
   • Create an omnetpp.ini file within the simulation directory.
   • Determine simulation parameters like duration and network parameters:

[General]

network = SDNNetwork

sim-time-limit = 100s

# SDN Controller parameters

**.controller.sdnController.configStartTime = 1s

Step 7: Build and Run the Simulation

1. Build the Project:
   • In the OMNeT++ IDE, right-click on project and pick Build Project.
2. Run the Simulation:
   • Go to Run -> Run Configurations.
   • Build a new run configuration for your project and run the simulation.

Step 8: Analyze Results

1. View Simulation Results:
   • Use OMNeT++’s tools to analyze the results once the simulation is finished.
   • Open the ANF (Analysis Framework) to visualize and interpret the data.

We hope that this demonstration will walk you through the basic network set up, how to implement the SDN, its functionalities and INET framework in OMNeT++. We can offer you another script about another simulation process for your reference.

For the implementation of satellite communication in OMNeT++, you may contact us to obtain optimal simulation and project performance outcomes from our expert developers. We specialize in executing SDN-specific protocols.