How to Begin Implement Network Stalling in NS3

To implement Network Stalling using NS3 that denotes the temporary halt of data transmission within a network, which is frequently triggered by congestion, link failures, or resource contention. To replicate the network stalling comprises of purposely launching the conditions, which can direct to halting and observing their influence over network performance parameters like throughput, latency, and packet loss in ns3.

Below is an ordered mechanism to get started with implementing Network Stalling in ns3:

Steps to Begin Implement Network Stalling in NS3

1. Understand Network Stalling

• Causes of Stalling:
  • Inadequate buffer space.
  • Link failures.
  • Packet retransmissions by reason of errors.
  • Network congestion.
• Metrics to Measure:
  • Recovery time after stalling.
  • Throughput drop in the course of stalling.
  • Packet delays and losses.

2. Set Up ns3

• We should install and set up ns3, if not already done:

./waf configure –build-profile=debug –enable-examples –enable-tests

./waf build

• Confirm the set up by running:

./waf –run hello-simulator

3. Define the Stalling Scenario

• Choose the Cause: Congestion, link failures, or limited buffer space.
• Simulate Impact: Launch stalling conditions and then observe its impacts.

4. Set Up a Basic Network

Make a basic network topology for monitoring the stalling.

Example: Basic Topology

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

using namespace ns3;

int main(int argc, char *argv[])

{

Time::SetResolution(Time::NS);

// Create nodes

NodeContainer nodes;

nodes.Create(3); // Client, Router, Server

// Configure point-to-point links

PointToPointHelper p2p;

p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));

// Install devices

NetDeviceContainer devices1 = p2p.Install(nodes.Get(0), nodes.Get(1)); // Client to Router

NetDeviceContainer devices2 = p2p.Install(nodes.Get(1), nodes.Get(2)); // Router to Server

// Install Internet stack

InternetStackHelper stack;

stack.Install(nodes);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces1 = address.Assign(devices1);

address.SetBase(“10.1.2.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces2 = address.Assign(devices2);

// Configure routing

Ipv4GlobalRoutingHelper::PopulateRoutingTables();

// Set up a UDP echo server on Node 2

uint16_t port = 9;

UdpEchoServerHelper echoServer(port);

ApplicationContainer serverApp = echoServer.Install(nodes.Get(2));

serverApp.Start(Seconds(1.0));

serverApp.Stop(Seconds(10.0));

// Set up a UDP echo client on Node 0

UdpEchoClientHelper echoClient(interfaces2.GetAddress(1), port);

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

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(0.1)));

echoClient.SetAttribute(“PacketSize”, UintegerValue(512));

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

clientApp.Start(Seconds(2.0));

clientApp.Stop(Seconds(10.0));

// Run simulation

Simulator::Run();

Simulator::Destroy();

return 0;

}

5. Introduce Stalling Conditions
6. Congestion

• Introduce numerous flows comparing for the similar link.
• Dynamically minimize link bandwidth.

Simulator::Schedule(Seconds(5.0), [&]() {

p2p.SetDeviceAttribute(“DataRate”, StringValue(“1Mbps”)); // Reduce bandwidth

NS_LOG_UNCOND(“Link bandwidth reduced to simulate congestion.”);

});

1. Link Failure

• Temporarily inactivate a link for replicating the network stalling.

void SimulateLinkFailure(Ptr<Node> node, uint32_t deviceIndex)

{

Ptr<NetDevice> device = node->GetDevice(deviceIndex);

device->SetReceiveCallback(MakeNullCallback<bool, Ptr<NetDevice>, Ptr<const Packet>, uint16_t, const Address &>());

NS_LOG_UNCOND(“Link failure simulated at ” << Simulator::Now().GetSeconds() << ” seconds.”);

}

Simulator::Schedule(Seconds(6.0), &SimulateLinkFailure, nodes.Get(1), 1); // Fail Router to Server link

1. Buffer Overflow

• Restrict the queue size for replicating the packet drops.

p2p.SetQueue(“ns3::DropTailQueue”, “MaxSize”, StringValue(“10p”)); // Set small buffer size

6. Monitor and Log Metrics
7. Throughput

• Monitor total bytes that are received on the destination nodes.

uint64_t totalBytesReceived = 0;

void ThroughputCallback(Ptr<const Packet> packet)

{

totalBytesReceived += packet->GetSize();

}

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

double throughput = (totalBytesReceived * 8.0) / 10.0; // Bits per second

NS_LOG_UNCOND(“Throughput: ” << throughput << ” bps”);

});

1. Packet Loss

• Observe the transmitted packets and effectively received packets.

uint32_t packetsSent = 0;

uint32_t packetsReceived = 0;

void PacketSentCallback(Ptr<const Packet> packet)

{

packetsSent++;

}

void PacketReceivedCallback(Ptr<const Packet> packet)

{

packetsReceived++;

}

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

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

NS_LOG_UNCOND(“Packet Loss Rate: ” << lossRate << “%”);

});

1. Recovery Time

• Assess the duration to retrieve for the network after stalling.

Time stallStartTime;

bool stalled = false;

void MonitorRecovery(Ptr<const Packet> packet)

{

if (stalled)

{

Time recoveryTime = Simulator::Now() – stallStartTime;

NS_LOG_UNCOND(“Recovery Time: ” << recoveryTime.GetSeconds() << ” seconds.”);

stalled = false;

}

}

Simulator::Schedule(Seconds(5.0), []() {

stallStartTime = Simulator::Now();

stalled = true;

NS_LOG_UNCOND(“Stalling started at ” << stallStartTime.GetSeconds() << ” seconds.”);

});

7. Run and Test

• Construct the script and execute the simulation:

./waf –run scratch/network-stalling

• Monitor the performance parameters within the logs.

8. Analyze and Visualize Results

• Equate the indicators before, during, and after stalling.
• Transfer information into a file to leverage tools like gnuplot or Python for visualization.

9. Enhance the Simulation

• Replicate more complex stalling situations:
  • Mimic application-layer timeouts.
  • Estimate the stalling recovery approaches like retransmissions, rerouting.
• Integrate redundancy or backup routes to moderate stalling.

Through NS3 simulator, we were able to conduct a detailed implementation process, which addressing the Network Stalling needs, analysing and visualizing its outcomes. If you need to customize it, we will assist you.