How to Start Dual Ring Topology projects using OMNeT++

To stimulate a Dual Ring Topology project in OMNeT++, we require building a network in which devices are organized in the two interconnected loops. This kind of topology is often used in environment in which the fault tolerance and redundancy are needed, such as in Fibre Channel or Metro Ethernet networks. In a Dual Ring topology, every node has two paths to communicate by other nodes, it delivers the protection for one path fails.

In OMNeT++, we will design this topology using NED files for the network explanation and C++ files for behavior of the nodes. Here is a step-by-step guide to help you get started:

Steps to Start Dual Ring Topology projects using OMNeT++

  1. Install OMNeT++

First, enable which OMNeT++ is installed on the machine. If you have not installed it yet, you can download it from the official OMNeT++ website. Monitor the installation procedures for platform.

  1. Create a New OMNeT++ Project
  1. Go to the OMNeT++ IDE.
  2. Start the File > New > OMNeT++ Project.
  3. Choose the Simple Network as the template.
  4. Name the project for sample DualRingTopology.
  5. Click Finish.

This will be built a general the OMNeT++ project with a *.ned file and *.ini setting a file.

  1. Define the Dual Ring Topology in NED Files

A Dual Ring Topology contains the nodes organized in two interconnected rings. We design this in OMNeT++, we will explain a network in which every node is linked the two neighbours in two various directions.

Example: DualRingTopology.ned

network DualRingTopology

{

submodule node1: NetworkNode;

submodule node2: NetworkNode;

submodule node3: NetworkNode;

submodule node4: NetworkNode;

submodule node5: NetworkNode;

connections:

node1.out1 –> node2.in1;

node2.out1 –> node3.in1;

node3.out1 –> node4.in1;

node4.out1 –> node5.in1;

node5.out1 –> node1.in1;

node1.out2 <– node5.in2;

node2.out2 <– node1.in2;

node3.out2 <– node2.in2;

node4.out2 <– node3.in2;

node5.out2 <– node4.in2;

}

simple module NetworkNode

{

parameters:

@display(“i=device/server”);

gates:

input in1;

input in2;

output out1;

output out2;

}

Explanation of the NED File:

  • DualRingTopology: This describes the overall network topology through five nodes organized the dual ring.
  • NetworkNode: Signify the every device in the network. Every node has two received and two sending the gates for instance for the two rings.
  • Connections: The nodes are linked in two directions for sample one for each ring. For sample, node1.out1 is connected to node2.in1, and node1.out2 is connected to node5.in2.

This architecture assures which every node has two paths to communicate by its neighbours: one through the first ring and another through the second ring.

  1. Implement Node Behavior in C++

Currently, we want describe on how every node behaves, like as how it sends and receives communication. We can explain this in the C++ source code of the module.

Example: NetworkNode.cc

#include <omnetpp.h>

class NetworkNode : public cSimpleModule

{

private:

cMessage *message; // to simulate data transmission

protected:

virtual void initialize() override;

virtual void handleMessage(cMessage *msg) override;

void transmitData();

void receiveData(cMessage *msg);

public:

~NetworkNode();

};

Define_Module(NetworkNode);

void NetworkNode::initialize()

{

message = new cMessage(“dataMessage”);

 

// Start by transmitting a message on the first ring

if (getIndex() == 0) {

transmitData();

}

}

void NetworkNode::handleMessage(cMessage *msg)

{

if (msg == message) {

// Transmit the message to the next node in the ring

transmitData();

} else {

// Handle incoming message (for simplicity, we just print it)

receiveData(msg);

}

}

void NetworkNode::transmitData()

{

// Create a new message

cMessage *msg = new cMessage(“data”);

int nextNode = (getIndex() + 1) % 5; // Circular transmission (next node in the ring)

// Send the message on the first output

send(msg, “out1”, nextNode);

// For the second ring, send the message in the reverse direction

send(msg, “out2”, (getIndex() + 4) % 5); // Send to the previous node (reverse direction)

// Schedule the next message transmission

scheduleAt(simTime() + 1.0, message);

}

void NetworkNode::receiveData(cMessage *msg)

{

// Print out the received data for now

EV << “Node ” << getIndex() << ” received data: ” << msg->getName() << “\n”;

delete msg;

}

NetworkNode::~NetworkNode()

{

cancelAndDelete(message);

}

Explanation of the C++ Code:

  • transmitData(): This operates the forwarding the communication to the another node in the first and second rings. The nodes are linked in the loop, so the index for the next node is calculated using the modulo operator ((getIndex() + 1) % 5 for the first ring and (getIndex() + 4) % 5 for the reverse ring).
  • handleMessage(): This works are maintain the communication after they are received. In this simple design, the node just designs the communication’s name.
  • initialize(): At the launch for the replication, node 0 initialize the forwarding the data.
  1. Configure Simulation Parameters

We require to setting the parameter metrices for the replication like as network topology, duration for the replication, and node behavior. This is done in the omnetpp.ini setting a file.

Example: omnetpp.ini

[General]

network = DualRingTopology

sim-time-limit = 100s

**.node*.messageInterval = 1s

**.node*.out1.delay = 0.5s

**.node*.out2.delay = 0.5s

Explanation:

  • network: Stipulates the name for the network module like as DualRingTopology.ned.
  • sim-time-limit: Configure the high replication time such as 100 seconds in this case.
  • node.messageInterval*: Describe the interval among the communication for every node for sample 1 second in this example.
  • node.out1.delay and node.out2.delay**:We can enhance the delays among transmissions for many paths such as rings we replicate the various transmission latencies.
  1. Compile the Project

After your NED and C++ files are ready, compile the project:

  1. In the OMNeT++ IDE, right-click on the project and choose the Build Project.
  2. OMNeT++ will compile the code, created will be executable.
  1. Run the Simulation

Currently that the project is compiled:

  1. Right-click on the project and choose the Run As > OMNeT++ Simulation.
  2. The process will replicate, and we will able to follow on how the data is transmitted around the dual rings.
  1. Analyze Results

After running the simulation, you can analyze the results:

  • Simulation GUI: The OMNeT++ offers a graphical user interface which permits the view of the network and follow on how the data flows by the nodes in the rings.
  • Result Analysis: Use the scavetool or other examine tools we extract statistics like as delivery the communication times, delays for the transmission, and throughput.
  1. Extend the Simulation

We can encompass the replication in different ways:

  • Fault Tolerance: Apply the fault tolerance through replicating the failure for one of the rings and view on how the systems enhance the second ring.
  • Multiple Traffic Flows: Design the several congestion flows among the nodes, perhaps launching the congestion or prioritization.
  • Error Handling: Launch the random packet losses, delays, or corruptions we replicate the further realistic surroundings.

By following these steps, you’ll have created a Dual Ring Topology project in OMNeT++ that simulates data transmission with redundancy, offering fault tolerance in the network. You can build on this foundation to explore more advanced concepts, such as dynamic topology changes, congestion control, and fault recovery.

With this configuration, we can exhaustively make you understand the implementation steps of offered example regarding Dual Ring Topology using OMNeT++ simulator tools. For further queries regarding this manual, we will resolve it over another manual.