How to Begin Implement Network Connectivity Robustness in NS3

To begin implementing and analyzing the Network Connectivity Robustness in NS3, we can adhere to these comprehensive steps. Connectivity robustness supports to estimate the network capacity to sustain the connections in diverse conditions like node failures, mobility, or interference. Here is a sequential approach on how to execute the Network Connectivity Robustness in NS3.

Steps to Begin Implement Network Connectivity Robustness in NS3

1. Understand Connectivity Robustness

Network connectivity robustness in NS3 based on:

• Topology resilience: The network capacity to manage the node or link failures.
• Routing protocols: To determine the alternative paths effectively.
• Interference handling: The capability of network to moderate the packet loss by reason of noise or congestion.

Below are performance parameters for estimating the robustness:

• Number of connected components: During failures we have to remain low.
• Packet delivery ratio (PDR): Estimate the percentage of packets that are effectively distributed.
• Latency: Compute the delay within redirecting traffic.
• Throughput: Effectively assess the data which are sent for each unit time.

2. Set Up Your Environment

Make sure that we have install ns3 on the system. Make acquainted with the simple ns3 scripts.

3. Create the Network Topology

Example: Wireless Topology

NodeContainer nodes;

nodes.Create(10); // Create 10 nodes

MobilityHelper mobility;

mobility.SetPositionAllocator(“ns3::GridPositionAllocator”,

“MinX”, DoubleValue(0.0),

“MinY”, DoubleValue(0.0),

“DeltaX”, DoubleValue(50.0),

“DeltaY”, DoubleValue(50.0),

“GridWidth”, UintegerValue(3),

“LayoutType”, StringValue(“RowFirst”));

mobility.SetMobilityModel(“ns3::ConstantPositionMobilityModel”);

mobility.Install(nodes);

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”);

NetDeviceContainer devices;

devices = wifi.Install(phy, mac, nodes);

4. Set Up the Internet Stack

We can install the Internet stack 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. Simulate Traffic

For replicating the traffic among nodes, we should install applications.

Example: UDP Traffic

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(0)); // Node 0 is the server

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(100.0));

UdpEchoClientHelper echoClient(interfaces.GetAddress(0), 9);

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

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(0.5))); // 0.5s interval

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

ApplicationContainer clientApps = echoClient.Install(nodes.Get(9)); // Node 9 is the client

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(100.0));

6. Simulate Failures

Launch network failures for analyzing the robustness:

Node Failures

Design nodes to move on offline:

Ptr<Node> failingNode = nodes.Get(3);

Simulator::Schedule(Seconds(20.0), &Node::SetAttribute, failingNode, “Enable”, BooleanValue(false));

Link Failures

Replicate a link failure:

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

Simulator::Schedule(Seconds(20.0), &PointToPointNetDevice::SetReceiveErrorModel, device, Ptr<ErrorModel>());

Interference

Make use of an error model to launch interference:

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

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

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

7. Track Connectivity Metrics

Monitor Packet Delivery Ratio (PDR)

Record the packets that are effectively transmitted and inherited:

uint32_t packetsSent = 0, 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));

Calculate Connectivity Robustness

Leverage adjacency matrix or graph algorithms to determine the volume of modules which are associated within the network. It can be executed by helper function or external tools such as Python.

8. Use FlowMonitor for Automated Analysis

FlowMonitor offers in-depth analysis on performance metrics like packet loss, throughput, and delay:

FlowMonitorHelper flowmon;

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

Simulator::Stop(Seconds(100.0));

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 << ”  PDR: ” << (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

• NetAnim: Envision the network topology and connectivity using NetAnim which is used for visualization:

AnimationInterface anim(“network_connectivity.xml”);

• Graphing Tools: Transfer parameters such as PDR, throughput into a file and examine it utilising external tools like MATLAB or Excel.

10. Experiment and Optimize

• Experiment various routing protocols such as AODV, OLSR for resilience.
• Fine-tune node mobility and monitor effect on connectivity.
• Integrate the redundancy for instance several paths, enhancing the robustness.

11. Run the Simulation

Execute the simulation and also monitor parameters of connectivity:

Simulator::Run();

Simulator::Destroy();

In this manual, Network Connectivity Robustness was outlined with clear and structured implementation approach using NS3 tool with sample coding. We can expand it further for advanced comprehension.