How to Start Fibre Channel Arbitrated Topology Using OMNeT++

To stimulate a Fibre Channel Arbitrated Topology project using OMNeT++, we will replicate the Fibre Channel (FC) network, typically used in Storage Area Networks (SANs), that contains the arbitration among devices are linked in the loop topology for sample FC-AL – Fibre Channel Arbitrated Loop. While OMNeT++ does not have the out-of-the-box design for Fibre Channel, we can design and replicate this behavior through developing the own network topology, arbitration mechanism, and the communication the protocol.

Here’s a step-by-step guide to start a Fibre Channel Arbitrated Topology project in OMNeT++:

Steps to Start Fibre Channel Arbitrated Topology Projects Using OMNeT++

  1. Install OMNeT++

Enable we have OMNeT++ installed. We can install the OMNeT++ from the official website. Next installation, open the IDE.

  1. Understanding Fibre Channel Arbitrated Loop (FC-AL)

Previously diving into the project, recognize the main components for Fibre Channel Arbitrated Loop (FC-AL):

  • Arbitration: The devices are network take chances the transferring data. Arbitration chooses that device gets to transmit the data at any given duration.
  • Loop Topology: Devices for instance like HBAs, switches, or storage are linked in a loop.
  • Frame-based Communication: Devices are tranfer the data in the form of settings to other devices in the loop.

The arbitration processes are vital and assure which no two devices transfers the data at the similar duration. Devices in the loop essential “request the right to send” and only one device is permit to transfer at a time.

  1. Create a New OMNeT++ Project
  1. Start OMNeT++ IDE.
  2. Select File > New > OMNeT++ Project.
  3. Go to Simple Network as a template.
  4. Enter a name for your project for sample FibreChannelProject.
  5. Click Finish to build the general files.
  1. Define the FC-AL Topology Using NED Files

In OMNeT++, we will define the network topology using NED files. In a Fibre Channel Arbitrated Loop, devices are linked in a loop. For sample, we can component four Fibre Channel devices are linked in the loop such as device 1 → device 2 → device 3 → device 4 → device 1.

Example: FibreChannelAL.ned

network FibreChannelAL

{

submodule device1: FibreChannelDevice;

submodule device2: FibreChannelDevice;

submodule device3: FibreChannelDevice;

submodule device4: FibreChannelDevice;

connections:

device1.out –> device2.in;

device2.out –> device3.in;

device3.out –> device4.in;

device4.out –> device1.in;

}

simple module FibreChannelDevice

{

parameters:

@display(“i=device/server”);

gates:

input in;

output out;

}

Explanation of the NED File:

  • FibreChannelAL: Describes the overall network in which the devices are linked in a loop.
  • FibreChannelDevice: Characterize the every Fibre Channel device, such as Host Bus Adapter (HBA), storage device, or switch.
  • The connections section connections every device in a loop, in which every device can pass communicate to the device.
  1. Modeling the Fibre Channel Arbitration Mechanism

A main feature of FC-AL is the arbitration mechanism. This can be designed in OMNeT++ through replicating the behavior for every device trying to improvement the “right to send” over the loop. We require the design in which every device are periodically checks if its turn the forwarding.

For simplicity, let’s assign which devices in the loop are arbitrated in a round-robin fashion. Here’s how we could apply it.

Example: FibreChannelDevice.cc

#include <omnetpp.h>

class FibreChannelDevice : public cSimpleModule

{

private:

bool isTurnToTransmit = false;

cMessage *arbitrationMsg = nullptr;

protected:

virtual void initialize() override;

virtual void handleMessage(cMessage *msg) override;

void startArbitration();

void transmitData();

void receiveData(cMessage *msg);

public:

~FibreChannelDevice();

};

Define_Module(FibreChannelDevice);

void FibreChannelDevice::initialize()

{

arbitrationMsg = new cMessage(“arbitration”);

if (isTurnToTransmit) {

transmitData();

} else {

scheduleAt(simTime() + 1.0, arbitrationMsg);  // Trigger periodic arbitration

}

}

void FibreChannelDevice::handleMessage(cMessage *msg)

{

if (msg == arbitrationMsg) {

startArbitration();

}

else {

// Handle incoming data frame

receiveData(msg);

}

}

void FibreChannelDevice::startArbitration()

{

if (isTurnToTransmit) {

transmitData();

} else {

// Device waits for its turn (simple round-robin arbitration)

scheduleAt(simTime() + 1.0, arbitrationMsg);  // Wait for the next round of arbitration

}

}

void FibreChannelDevice::transmitData()

{

// Create a data frame

cMessage *msg = new cMessage(“data”);

send(msg, “out”);  // Send the data to the next device

// Mark that this device has transmitted and doesn’t have the right to send again

isTurnToTransmit = false;

// Notify the next device to arbitrate (this can be expanded with actual frame transmission simulation)

scheduleAt(simTime() + 1.0, arbitrationMsg);  // Schedule arbitration for the next round

}

void FibreChannelDevice::receiveData(cMessage *msg)

{

// Handle received data (for simplicity, just delete the message)

delete msg;

}

FibreChannelDevice::~FibreChannelDevice()

{

cancelAndDelete(arbitrationMsg);

}

Explanation of C++ Code:

  • Arbitration: The startArbitration() works replicate the round-robin arbitration process, in which every device check it’s become to forwarding.
  • Transmit Data: it is the device’s turn and forwarding the data frame such as modeled as a message to the another device in the loop using the transmitData() function.
  • Receive Data: After a device accepts a communication, it processes it like as for simplicity; we just eliminate it in the sample.
  1. Configure the Simulation Parameters

The parameter metrices are replicate, like as the duration of arbitration, the amount of devices, and duration for the replication, can be setting in the omnetpp.ini file.

Example: omnetpp.ini

[General]

network = FibreChannelAL

sim-time-limit = 100s

**.device1.isTurnToTransmit = true

**.device2.isTurnToTransmit = false

**.device3.isTurnToTransmit = false

**.device4.isTurnToTransmit = false

Explanation:

  • network: Describe the network topology file for instance FibreChannelAL.ned.
  • sim-time-limit: Sets the increase the duration for the replication for sample 100 seconds.
  • isTurnToTransmit: Setting that device starts the arbitration and has correct to forwarding the data.
  1. Compile the Project
  1. Right-click on the project folder and choose Build Project in OMNeT++ IDE.
  2. OMNeT++ will compile the code, and executable will be created.
  1. Run the Simulation

Once the project is compiled:

  1. Right-click on the project folder and choose Run As > OMNeT++ Simulation.
  2. It starts the replication, and we will view the devices are accepting to sending the data in a round-robin fashion.
  1. Analyze the Results

OMNeT++ permits to envision and examine the outcomes:

  • Simulation GUI: Follow on how the devices communicate, send data, and arbitrate in real time.
  • Result Analysis: OMNeT++ delivers the outcomes examine the tools like scavetool for performance analysis for sample throughput, latency, etc.

You can alter the logic, enhance the arbitration mechanism, and design the further complex behaviours like as error handling, collision avoidance, or even setting routing for a additional realistic replication.

  1. Extend the Simulation

We build the replication for many correct or difficult, they are:

  • Add advanced arbitration logic: For instance, apply the priority-based arbitration or replicate the further different environment by many loops.
  • Introduce delays and bandwidth limitations: we can design the realistic delays in the communication, bandwidth constraints, or packet losses.
  • Support different Fibre Channel topologies: For example, generate a point-to-point connections or switched topologies as an alternative for just an arbitrated loop.

By following these steps, you’ll have a good foundation to model a Fibre Channel Arbitrated Topology in OMNeT++ and can further extend it to meet your specific needs.

In above manual clearly shows about how the Fibre Channel Arbitrated Topology projects will be simulated and analyse the results in OMNeT++ tool. A dedicated manual will be shared to handle further queries about this project.