How to Calculate Network Gateways in ns3

To calculate network gateways in ns3, we need to set up a network with nodes acting as gateways to route traffic between different subnets or segments. This process incorporates measuring performance metrics like throughput, latency, and packet loss to calculate the effectiveness of the gateways. Here are the steps to achieve this.

Steps for calculating network gateways

1. Set up the simulation :

• Make sure that ns3 is installed in the computer. If not, install it and include necessary modules.

2. Define Network Topology:

• create the network topology by incorporating gateway nodes connecting different subnets.

3. Configure routing:

• To enable traffic forwarding between subnets, Configure routing protocols on the gateway nodes.

4. Configure Applications:

• On the nodes, setup applications to generate and receive traffic.

5. Monitor Performance Metrics:

• To monitor performance metrics such as throughput, latency, and packet loss, use trace sources or callbacks.

6. Analyze Gateway Performance:

• To evaluate the network gateways, calculate and log the performance metrics.

Example code

Here is an example to set up a basic simulation to calculate the performance of network gateways in ns3.

#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”

#include “ns3/flow-monitor-module.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“NetworkGatewayExample”);

void CalculateGatewayPerformance (Ptr<FlowMonitor> flowMonitor, FlowMonitorHelper &flowHelper)

{

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

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

double totalThroughput = 0.0;

double totalLatency = 0.0;

uint32_t totalPackets = 0;

uint32_t lostPackets = 0;

for (auto it = stats.begin (); it != stats.end (); ++it)

{

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

double throughput = it->second.rxBytes * 8.0 / (it->second.timeLastRxPacket.GetSeconds () – it->second.timeFirstTxPacket.GetSeconds ()) / 1024; // kbps

double latency = it->second.delaySum.GetSeconds () / it->second.rxPackets * 1000; // ms

uint32_t packets = it->second.rxPackets + it->second.lostPackets;

totalThroughput += throughput;

totalLatency += latency;

totalPackets += packets;

lostPackets += it->second.lostPackets;

}

double averageLatency = totalPackets > 0 ? totalLatency / stats.size () : 0;

double packetLoss = totalPackets > 0 ? (static_cast<double> (lostPackets) / totalPackets) * 100 : 0;

NS_LOG_UNCOND (“Total Throughput: ” << totalThroughput << ” kbps”);

NS_LOG_UNCOND (“Average Latency: ” << averageLatency << ” ms”);

NS_LOG_UNCOND (“Packet Loss: ” << packetLoss << ” %”);

}

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

{

CommandLine cmd;

cmd.Parse (argc, argv);

Time::SetResolution (Time::NS);

// Create nodes

NodeContainer nodes;

nodes.Create (6);

// Create point-to-point links

PointToPointHelper pointToPoint;

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

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

NetDeviceContainer devices01 = pointToPoint.Install (NodeContainer (nodes.Get (0), nodes.Get (1)));

NetDeviceContainer devices12 = pointToPoint.Install (NodeContainer (nodes.Get (1), nodes.Get (2)));

NetDeviceContainer devices23 = pointToPoint.Install (NodeContainer (nodes.Get (2), nodes.Get (3)));

NetDeviceContainer devices24 = pointToPoint.Install (NodeContainer (nodes.Get (2), nodes.Get (4)));

NetDeviceContainer devices25 = pointToPoint.Install (NodeContainer (nodes.Get (2), nodes.Get (5)));

// Install the internet stack on nodes

InternetStackHelper stack;

stack.Install (nodes);

// Assign IP addresses to the devices

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces01 = address.Assign (devices01);

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

Ipv4InterfaceContainer interfaces12 = address.Assign (devices12);

address.SetBase (“10.1.3.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces23 = address.Assign (devices23);

address.SetBase (“10.1.4.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces24 = address.Assign (devices24);

address.SetBase (“10.1.5.0”, “255.255.255.0”);

Ipv4InterfaceContainer interfaces25 = address.Assign (devices25);

// Enable static routing

Ipv4GlobalRoutingHelper::PopulateRoutingTables ();

// Create UDP server on node 3

UdpServerHelper server (9);

ApplicationContainer serverApp = server.Install (nodes.Get (3));

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

// Create UDP client on node 0

UdpClientHelper client (interfaces23.GetAddress (1), 9);

client.SetAttribute (“MaxPackets”, UintegerValue (320));

client.SetAttribute (“Interval”, TimeValue (MilliSeconds (10)));

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

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

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

FlowMonitorHelper flowHelper;

Ptr<FlowMonitor> flowMonitor = flowHelper.InstallAll ();

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

CalculateGatewayPerformance (flowMonitor, flowHelper);

Simulator::Destroy ();

return 0;

}

Explanation

1. Setup:

Created six nodes and those nodes are connected by point-to-point links. Node 1 and Node 2 act as gateways, connecting different subnets.

1. Internet Stack and Routing:

On all nodes, the internet stack is installed and static routing is enabled.

1. Applications:

On node 3, a UDP server is installed, and a UDP client is installed on node 0 to generate traffic.

1. Flow Monitor:

To gather performance metrics like throughput, latency, and packet loss, the FlowMonitor is used.

1. CalculateGatewayPerformance Function:

This function calculates the total throughput, average latency, and packet loss, and logs these metrics to evaluate the performance of the network gateways.

Running the Simulation

Compile and run the simulation by using the following commands :

./waf configure

./waf build

./waf –run your-script-name

Replace your-script-name with the actual name of your script file.

Overall, we had our simulation results on calculating network gateways in ns3 by setting up a network with nodes acting as gateways to route traffic between different subnets or segments. Also, we offer a deep guide on Network Gateways.Provide ns3simulation.com with all the specifics of your Network Gateways parameters for innovative outcomes. If you need assistance with networking performance, contact our skilled professionals.