How to Calculate Network Response Time in omnet++

To calculate network response time in OMNeT++ has needs to evaluate the time it takes for a request to be sent from a source node that managed by the destination node, and for a response to be received back at the source node and these performance metric is vital for familiarize the performance of communication systems, like web servers, where quick responses are necessary. The below are the procedures on how to calculate the network response time in OMNeT++:

Steps to Calculate Network Response Time in OMNeT++:

1. Set Up the Network Model:
   • Describe network topology using NED files in OMNeT++ and it contains to generate nodes like clients and servers and connecting them with proper links.
   • Make sure that the network model reflects the scenario where response time is acute, like in client-server architecture.
2. Implement Traffic Generation:
   • Use or generate modules that emulate the sending of requests from a client node to a server node and the subsequent response from the server back to the client.
   • We need to use UdpApp, TcpApp, or custom application modules to create the request/response traffic.
3. Track Request and Response Times:
   • At the client node, record the time when a request is sent.
   • When the response is received at the client, record the time again and compute the response time.
4. Calculate Response Time:
   • The response time for a request is computed using the formula: Response Time=Time Response Received−Time Request Sent\text{Response Time} = \text{Time Response Received} – \text{Time Request Sent}Response Time=Time Response Received−Time Request Sent

Example Implementation:

The given below is the sample of how to calculate response time in OMNeT++:

#include <omnetpp.h>

using namespace omnetpp;

class ClientModule : public cSimpleModule {

private:

simsignal_t responseTimeSignal;  // Signal for recording response time

simtime_t requestSentTime;       // Time when the request was sent

protected:

virtual void initialize() override {

// Register signal for response time

responseTimeSignal = registerSignal(“responseTime”);

// Schedule the first request to be sent

scheduleAt(simTime() + par(“sendInterval”).doubleValue(), new cMessage(“sendRequest”));

}

virtual void handleMessage(cMessage *msg) override {

if (strcmp(msg->getName(), “sendRequest”) == 0) {

// Send a request to the server

cMessage *request = new cMessage(“request”);

requestSentTime = simTime();

send(request, “out”);

// Schedule the next request

scheduleAt(simTime() + par(“sendInterval”).doubleValue(), new cMessage(“sendRequest”));

} else if (strcmp(msg->getName(), “response”) == 0) {

// Response received from the server

simtime_t responseReceivedTime = simTime();

simtime_t responseTime = responseReceivedTime – requestSentTime;

// Emit the response time signal

emit(responseTimeSignal, responseTime);

delete msg;  // Delete the response message after processing

}

}

};

class ServerModule : public cSimpleModule {

protected:

virtual void handleMessage(cMessage *msg) override {

// Simulate processing of the request

simtime_t processingDelay = par(“processingDelay”).doubleValue();

scheduleAt(simTime() + processingDelay, msg);

}

virtual void finish() override {

// Respond back to the client

cMessage *response = new cMessage(“response”);

send(response, “out”);

}

};

Define_Module(ClientModule);

Define_Module(ServerModule);

Explanation:

• ClientModule:
  • initialize() Function: Registers the signal for recording response time and schedules the first request.
  • handleMessage() Function:
    • When a “sendRequest” message is received (indicating it’s time to send a new request), a request is sent to the server, and the send time is recorded.
    • When a response is received from the server, the response time is computed as the difference among the current time and the time the request was sent. This response time is then released for analysis.
• ServerModule:
  • handleMessage() Function: To emulate processing the request by delaying the response for a particular amount of time (processingDelay).
  • finish() Function: Sends the response back to the client after processing.

5. Run the Simulation:

• Compile OMNeT++ project and execute the simulation. After the simulation finalizes, the response times will be recorded as signals, which need to measure using OMNeT++’s built-in tools or export for external analysis.

6. Analyse and Interpret Results:

• The recorded response times provide insights into the network’s performance and how quickly it can manage the requests and deliver responses.
• Measuring the average response time, as well as its distribution that can support classify the performance bottlenecks or ineffectiveness in the network.

Additional Considerations:

• Processing Delays: The server’s processing delay can be an important factor in response time. Adjust this parameter to emulate diverse server loads.
• Network Delays: Make sure that the network links are configured with realistic delays to exactly model the scenario.
• Traffic Patterns: The pattern and frequency of requests can impact response times. Experiment with diverse traffic loads to monitor the effect.

From the following steps, we gathered the information about how to setup the network model and how to calculate the response time using the OMNeT++ tool that delivers the valuable insights among the communication system. Additional specific details were provided about the response time.

We provide simulation performance results on Network Response Time using the OMNeT++ tool. If you want a customized research experience, please reach out to us. Our expert team and advanced tools are ready to assist you with your research. To evaluate the performance of communication systems, share your parameter details for further assistance.