How to Calculate Network Application Response Time in omnet++

To calculate the Network Application Response Time in OMNeT++ has includes to evaluate the time taken for an application-level request to obtain a response from a remote service or server and these parameters is critical for measuring the performance of applications running over the network, as it directly affects the user experience. The given below is the procedures on how to execute the network application response time in OMNeT++:

Steps to Calculate Network Application Response Time in OMNeT++

1. Define Application Response Time:
   • Application Response Time is the time elapsed among when a request is sent from a client application and when the response is received by the client.
   • It contains the time taken for the request to travel to the server, the processing time at the server, and the time taken for the response to travel back to the client.
2. Track Request Sent Time:
   • When a request is sent from the client, record the time.

simtime_t requestSentTime = simTime();

1. Track Response Received Time:
   • When the equivalent response is received, record the time.

simtime_t responseReceivedTime = simTime();

1. Calculate Response Time:
   • The response time is the difference among the response received time and the request sent time.

simtime_t responseTime = responseReceivedTime – requestSentTime;

1. Store and Analyse Response Times:
   • Store the response time for each request/response pair. This can be completed in a vector or by directly gathering the total response time if we are only interested in the average.

std::vector<simtime_t> responseTimes;

responseTimes.push_back(responseTime);

1. Calculate and Record Metrics:
   • At the end of the simulation, we need to estimate the average response time, maximum response time, and other statistics.

simtime_t totalResponseTime = 0;

for (auto &time : responseTimes) {

totalResponseTime += time;

}

simtime_t averageResponseTime = totalResponseTime / responseTimes.size();

1. • Record the average response time using OMNeT++’s recordScalar function.

recordScalar(“Average Application Response Time (s)”, averageResponseTime.dbl());

EV << “Average Application Response Time: ” << averageResponseTime << ” s” << endl;

Example Implementation in OMNeT++

In the below is the sample to implement the calculation of network application response time in an OMNeT++ module:

class AppClient : public cSimpleModule {

private:

std::vector<simtime_t> responseTimes;  // Store all response times

protected:

virtual void initialize() override {

// Initialization logic, if any

}

virtual void handleMessage(cMessage *msg) override {

if (msg->isSelfMessage()) {

// Handle the case where this message is a self-message (e.g., for timers)

} else {

// Assuming msg is a packet containing the response

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

// Get the request sent time from the packet or stored context

simtime_t requestSentTime = pkt->par(“requestSentTime”);

// Calculate the response time

simtime_t responseReceivedTime = simTime();

simtime_t responseTime = responseReceivedTime – requestSentTime;

responseTimes.push_back(responseTime);

EV << “Response Time: ” << responseTime << ” s” << endl;

// Process the response packet further if necessary

delete pkt;  // Clean up the packet

}

}

virtual void finish() override {

// Calculate the average response time

if (responseTimes.empty()) {

EV << “No responses received. Cannot calculate average response time.” << endl;

return;

}

simtime_t totalResponseTime = 0;

for (auto &time : responseTimes) {

totalResponseTime += time;

}

simtime_t averageResponseTime = totalResponseTime / responseTimes.size();

// Record the average response time

recordScalar(“Average Application Response Time (s)”, averageResponseTime.dbl());

EV << “Average Application Response Time: ” << averageResponseTime << ” s” << endl;

}

};

Explanation:

1. Request Sent Time:
   • When the request is sent, time is recorded and stored in the packet as a parameter or observed within the client module.
2. Response Received Time:
   • When the response arrives, the time is recorded, and the difference from the request sent time provides the response time.
3. Recording and Analysing Response Times:
   • All response times are stored and measured at the end of the simulation. The average response time is estimated and recorded.
4. Flexibility:
   • This method is flexible and can be modified to compute further statistics, like the maximum response time, minimum response time, or response time distribution.

Through this approach, we deliberately learn the calculation process for application response time for network using the OMNeT++ tool. Additional specific details about the network response time will also be provided. To determine the Network Application Response Time using the OMNeT++ tool for your research, please share your parameter details with us, and we will provide you with the best guidance possible.