How to Begin Implement Network Reliability in NS3

To implement and examine the Network Reliability within ns3, it signifies the network‘s capability for effectively distributed the data packets in diverse conditions like node failures, link losses, or network congestion.

Steps to Begin Implement Network Reliability in NS3

1. Understand Network Reliability

Network reliability can be estimated by leveraging the performance parameters like:

• Packet Delivery Ratio (PDR): Estimate the percentage of packets that are received to total packets transmitted.
• Throughput: Compute the data effectively sent for each unit time.
• Delay: Measure the duration to pass through the network for a packet.
• Packet Loss Ratio: Assess the fraction of packets which are dropped to transmitted packets.

2. Set Up Your Environment

Make sure that we have installed ns3 and working properly. Get more knowledge about ns3 scripting.

3. Create the Network Topology

Example: Point-to-Point Topology

NodeContainer nodes;

nodes.Create(2);

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

pointToPoint.SetChannelAttribute(“Delay”, StringValue(“2ms”));

NetDeviceContainer devices;

devices = pointToPoint.Install(nodes);

Example: Wireless Topology

YansWifiChannelHelper channel = YansWifiChannelHelper::Default();

YansWifiPhyHelper phy = YansWifiPhyHelper::Default();

phy.SetChannel(channel.Create());

WifiHelper wifi;

wifi.SetStandard(WIFI_PHY_STANDARD_80211n);

WifiMacHelper mac;

mac.SetType(“ns3::AdhocWifiMac”);

NodeContainer wifiNodes;

wifiNodes.Create(5);

NetDeviceContainer wifiDevices;

wifiDevices = wifi.Install(phy, mac, wifiNodes);

4. Set Up the Internet Stack

We should install the Internet stack enabled for IP-based interaction:

InternetStackHelper stack;

stack.Install(nodes);

Ipv4AddressHelper address;

address.SetBase(“10.1.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces = address.Assign(devices);

5. Install Applications to Generate Traffic

Example: UDP Traffic

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(1));

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

UdpEchoClientHelper echoClient(interfaces.GetAddress(1), 9);

echoClient.SetAttribute(“MaxPackets”, UintegerValue(100));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(0.01))); // 10ms interval

echoClient.SetAttribute(“PacketSize”, UintegerValue(1024));

ApplicationContainer clientApps = echoClient.Install(nodes.Get(0));

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

6. Simulate Failures

Simulate Node Failures

Set nodes to move on offline for analyzing the reliability:

Ptr<Node> failingNode = nodes.Get(1);

Simulator::Schedule(Seconds(5.0), &Node::SetAttribute, failingNode, “Enable”, BooleanValue(false));

Simulate Link Failures

Simulate the failure link on certain time:

Ptr<PointToPointNetDevice> device = DynamicCast<PointToPointNetDevice>(devices.Get(1));

Simulator::Schedule(Seconds(5.0), &PointToPointNetDevice::SetReceiveErrorModel, device, Ptr<ErrorModel>());

Simulate Packet Drops

Integrate an error model for establishing packet drops:

Ptr<RateErrorModel> errorModel = CreateObject<RateErrorModel>();

errorModel->SetAttribute(“ErrorRate”, DoubleValue(0.1)); // 10% error rate

devices.Get(1)->SetAttribute(“ReceiveErrorModel”, PointerValue(errorModel));

7. Measure Reliability Metrics

Packet Delivery Ratio (PDR)

Monitor the PDR which are transmitted and inherited packets to estimate the metrics:

uint32_t packetsSent = 0;

uint32_t packetsReceived = 0;

void PacketSentCallback(Ptr<const Packet> packet) {

packetsSent++;

}

void PacketReceivedCallback(Ptr<const Packet> packet) {

packetsReceived++;

}

devices.Get(0)->TraceConnectWithoutContext(“MacTx”, MakeCallback(&PacketSentCallback));

devices.Get(1)->TraceConnectWithoutContext(“MacRx”, MakeCallback(&PacketReceivedCallback));

At the end of the simulation, determine the PDR:

Simulator::Schedule(Seconds(10.0), [] {

double pdr = (static_cast<double>(packetsReceived) / packetsSent) * 100;

std::cout << “Packet Delivery Ratio: ” << pdr << “%” << std::endl;

});

Throughput

Observe throughput with the support of custom callback:

void MonitorThroughput(Ptr<PacketSink> sink) {

double throughput = sink->GetTotalRx() * 8.0 / 1e6; // Mbps

std::cout << “Throughput: ” << throughput << ” Mbps at time ” << Simulator::Now().GetSeconds() << “s\n”;

Simulator::Schedule(Seconds(1.0), &MonitorThroughput, sink);

}

Delay

Record packet timestamps for measuring delay:

std::map<uint64_t, Time> sentTimes;

void PacketSent(Ptr<const Packet> packet) {

sentTimes[packet->GetUid()] = Simulator::Now();

}

void PacketReceived(Ptr<const Packet> packet) {

uint64_t uid = packet->GetUid();

if (sentTimes.find(uid) != sentTimes.end()) {

Time delay = Simulator::Now() – sentTimes[uid];

std::cout << “Packet ID: ” << uid << “, Delay: ” << delay.GetSeconds() << “s” << std::endl;

}

}

8. Use FlowMonitor for Automated Analysis

Make use of FlowMonitor for automated analysis to monitor the performance parameters in terms of throughput, delay, and packet loss.

Configure FlowMonitor

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

Simulator::Stop(Seconds(10.0));

Simulator::Run();

monitor->CheckForLostPackets();

Ptr<Ipv4FlowClassifier> classifier = DynamicCast<Ipv4FlowClassifier>(flowmon.GetClassifier());

std::map<FlowId, FlowMonitor::FlowStats> stats = monitor->GetFlowStats();

for (auto& flow : stats) {

Ipv4FlowClassifier::FiveTuple t = classifier->FindFlow(flow.first);

std::cout << “Flow ID: ” << flow.first << ” (” << t.sourceAddress << ” -> ” << t.destinationAddress << “)\n”;

std::cout << ”  Packet Loss Ratio: ”

<< (flow.second.txPackets – flow.second.rxPackets) * 100.0 / flow.second.txPackets << “%\n”;

std::cout << ”  Average Delay: ” << flow.second.delaySum.GetSeconds() / flow.second.rxPackets << “s\n”;

}

9. Visualize Results

• Monitor the failures and its effect using NetAnim:

AnimationInterface anim(“network_reliability.xml”);

• Transfer performance parameters into a file leveraging external tools such as MATLAB or Excel for detailed analysis.

10. Experiment and Optimize

• Experiment diverse topologies and protocols such as OLSR, AODV.
• Modify link and node metrics like bandwidth, error rates.
• Measure the impact of redundancy for instance numerous paths, backup nodes.

11. Run the Simulation

Now, we execute the simulation and examine the outcomes:

Simulator::Run();

Simulator::Destroy();

We had shared substantial insights and basic implementation strategy which helps you to execute and examine the Network Reliability using NS3 environment. Further explanations can be provided upon request.