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How to Implement Network Delay Assessment in OMNeT++

To implement the network delay assessment in OMNeT++, we have to simulate a network that includes estimating and evaluating the time taken for packets to moves from the source to the destination. Network delay is vital metric for assessing the performance of multiple network protocols and configurations. Use the demonstration to complete this implementation in OMNeT++:

Step-by-Step Implementation:

  1. Set Up OMNeT++ and INET Framework:
  • Install OMNeT++: Make certain that you have installed the OMNeT++.
  • Install INET Framework: Download and install the INET framework that offers models for network protocols and elements essential for the simulation.
  1. Define the Network Topology:

Generating the basic network topology in which we will compute the delay. For instance, we’ll use a straightforward topology with two hosts linked through a router.

Example NED File (DelayAssessmentNetwork.ned):

package mynetwork;

import inet.node.inet.Router;

import inet.node.inet.StandardHost;

network DelayAssessmentNetwork

{

submodules:

hostA: StandardHost {

@display(“p=100,200”);

}

router: Router {

@display(“p=300,200”);

}

hostB: StandardHost {

@display(“p=500,200”);

}

connections allowunconnected:

hostA.pppg++ <–> ethernetLine <–> router.pppg++;

router.pppg++ <–> ethernetLine <–> hostB.pppg++;

}

This basic network has two hosts (hostA and hostB) connected over a router.

  1. Configure Traffic Generation:

We have to create traffic amongst nodes to compute the delay. We’ll use a UDP application to send packets from hostA to hostB.

Example Traffic Configuration in omnetpp.ini:

network = DelayAssessmentNetwork

**.hostA.numApps = 1

**.hostA.app[0].typename = “UdpBasicApp”

**.hostA.app[0].destAddresses = “hostB”

**.hostA.app[0].destPort = 1234

**.hostA.app[0].messageLength = 1024B

**.hostA.app[0].sendInterval = 1s

**.hostB.numApps = 1

**.hostB.app[0].typename = “UdpSink”

**.hostB.app[0].localPort = 1234

In this configuration:

  • hostA sends UDP packets to hostB at regular breaks.
  • hostB receives these packets and can log the arrival time for delay assessment.
  1. Implement Delay Measurement:

To estimate the delay, we will log the time when each packet is sent and compare it with the time the packet is received at the destination.

Example Delay Measurement Implementation:

// In UdpBasicApp (sending side)

void UdpBasicApp::sendPacket() {

auto packet = createPacket(“DataPacket”);

packet->addTag<CreationTimeTag>()->setCreationTime(simTime());  // Tag the packet with the current time

send(packet, “socketOut”);

}

// In UdpSink (receiving side)

void UdpSink::handleMessage(cMessage *msg) {

auto packet = check_and_cast<Packet *>(msg);

simtime_t creationTime = packet->getTag<CreationTimeTag>()->getCreationTime();

simtime_t delay = simTime() – creationTime;  // Calculate delay

recordScalar(“End-to-End Delay”, delay.dbl());  // Record delay

delete packet;

}

This code adds a CreationTimeTag to each packet when it’s sent, and then calculates the delay when the packet is received.

  1. Simulate and Record Delay Metrics:

Log the delay metrics in the course of simulation by using OMNeT++’s recording features.

Example Configuration for Recording Delay Metrics:

network = DelayAssessmentNetwork

**.hostB.app[0].endToEndDelay.recordScalar = true

This configuration will record the end-to-end delay for each packet received by hostB.

  1. Run the Simulation and Analyze Results:
  • Run the simulation: Begin the simulation and monitor how packets are transmitted from hostA to hostB.
  • Analyze the results: After the simulation, analyze the recorded delay values to evaluate the network’s performance.

Plot the delay over time or compute average delay metrics by using OMNeT++’s built-in analysis tools.

  1. Advanced Delay Assessment Scenarios:

You can extend the basic delay evaluation to more difficult scenarios like:

  • Variable Network Conditions: Introduce changing network conditions, such as changing bandwidth, congestion, or link failures, to see how they impact delay.
  • Multiple Traffic Flows: Simulate several traffic flows with various priorities and analyze how delay is influenced.
  • QoS Mechanisms: ExecuteQoS mechanisms that prioritize specific kinds of traffic and see how they reduce delay for high-priority flows.

Example: Adding Network Congestion

**.router.queue.packetCapacity = 10  # Introduce a small queue to simulate congestion

**.router.queueingDelay.recordScalar = true

By restraining the router’s queue capacity, you can simulate congestion and study its affects on delay.

  1. Document and Report Findings:

After completing the simulations, document the scenarios examined, the results acquired, and any enhancements made. This will help in understanding the factors affecting network delay and how to mitigate them.

Using this step-by-step guide with examples, we can know how to implement network delay assessment in OMNeT++ using the INET framework. If you need any information regarding this process, we will provide them. OMNetManual.com offers network simulation performance for your research work, providing you with the best outcomes by comparing your parameter details. You can access the implementation and simulation results for Network Delay Assessment in the OMNeT++ tool from us. If you need immediate support, please contact our team.

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