How to Calculate Network Load and Hop Count in ns3

To calculate network load and hop count in ns3, we need to measure the amount of traffic carried by the network and the number of hops packets traverse between source and destination. Here is a detailed guide on achieving this.

Steps for calculating network load and hop count

1. Set up the simulation :

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

2. Create Network Topology:

• create nodes and configure the network topology. Set up routing protocols as needed (e.g., OLSR, AODV for ad-hoc networks, or static routing for fixed networks).

3. Install applications :

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

4. Enable tracing and Metrics Collection:

• To capture relevant metrics such as transmitted and received packets and reception, use ns3 tracing capabilities.

5. Run the simulation :

• Execute the simulation and collect the trace data.

6. Analyze the results :

• Post-process the trace data to calculate the network load and hop count.

Example of a simple Network Load and Hop Count

Create a basic set up of network, generate traffic, and capture metrics to calculate network load and hop count 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/mobility-module.h”

#include “ns3/flow-monitor-module.h”

#include “ns3/config-store.h”

#include “ns3/olsr-helper.h”

using namespace ns3;

NS_LOG_COMPONENT_DEFINE (“NetworkLoadAndHopCountExample”);

void PacketReceivedCallback (Ptr<const Packet> packet, const Address &address)

{

NS_LOG_UNCOND (“Packet received: ” << packet->GetUid());

}

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

{

// Set up logging

LogComponentEnable (“UdpClient”, LOG_LEVEL_INFO);

LogComponentEnable (“UdpServer”, LOG_LEVEL_INFO);

// Create nodes

NodeContainer nodes;

nodes.Create (4);

// Create point-to-point links

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute (“DataRate”, StringValue (“5Mbps”));

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

NetDeviceContainer devices;

devices.Add (pointToPoint.Install (nodes.Get (0), nodes.Get (1)));

devices.Add (pointToPoint.Install (nodes.Get (1), nodes.Get (2)));

devices.Add (pointToPoint.Install (nodes.Get (2), nodes.Get (3)));

// Install Internet stack

InternetStackHelper stack;

OlsrHelper olsr;

stack.SetRoutingHelper (olsr); // Set OLSR as the routing protocol

stack.Install (nodes);

// Assign IP addresses

Ipv4AddressHelper address;

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

Ipv4InterfaceContainer interfaces = address.Assign (devices);

// Install UDP server on the last node

uint16_t port = 9; // Discard port (RFC 863)

UdpServerHelper server (port);

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

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (10.0));

// Install UDP client on the first node

UdpClientHelper client (interfaces.GetAddress (3), port);

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

client.SetAttribute (“Interval”, TimeValue (MilliSeconds (50)));

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

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

clientApp.Start (Seconds (2.0));

clientApp.Stop (Seconds (10.0));

// Set up FlowMonitor to collect performance metrics

FlowMonitorHelper flowmon;

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

// Run the simulation

Simulator::Stop (Seconds (11.0));

Simulator::Run ();

// Calculate network load and hop count

monitor->CheckForLostPackets ();

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

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

double totalLoad = 0.0;

double totalHops = 0.0;

int numFlows = 0;

for (std::map<FlowId, FlowMonitor::FlowStats>::const_iterator i = stats.begin (); i != stats.end (); ++i)

{

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

if (t.sourceAddress == Ipv4Address (“10.1.1.1”) && t.destinationAddress == Ipv4Address (“10.1.1.4”))

{

totalLoad += i->second.rxBytes * 8.0 / (i->second.timeLastRxPacket.GetSeconds () – i->second.timeFirstTxPacket.GetSeconds ());

totalHops += i->second.timesForwarded + 1; // timesForwarded counts only forwards, so +1 for the first hop

numFlows++;

}

}

double avgHopCount = totalHops / numFlows;

double avgLoad = totalLoad / numFlows;

NS_LOG_UNCOND (“Average Hop Count: ” << avgHopCount);

NS_LOG_UNCOND (“Average Load: ” << avgLoad << ” bps”);

// Clean up

Simulator::Destroy ();

return 0;

}

Explanation:

1. Setup Logging:
   • To track activities, enable logging for the UDP applications.
2. Create Nodes and Network:
   • Create nodes and set up point-to-point links between them.
3. Install Internet Stack and Routing Protocol:
   • On UEs, install the Internet stack.
   • Set OLSR as the routing protocol.
4. Assign IP Addresses:
   • Assign IP addresses to the network interfaces.
5. Install Applications:
   • On UEs, install UDP server applications.
   • Install UDP client applications on the UEs, sending traffic to the server.
6. Set Up FlowMonitor :
   • To collect and analyze flow statistics, install a FlowMonitor.
7. Run Simulation:
   • Run the simulation for the specified duration.
8. Calculate Link Success Rate :
   • Extract the flow statistics, after the simulation.
   • Calculate the total load (in bps) and total hops for the flows. Compute the average hop count and load.

Analyzing the Results:

• Network Load :
  • Network load is calculated as the average rate of data received in bits per second (bps).
• This metric provides an indication of the traffic carried by the network.
• Hop count :
  • Hop count is calculated as the average number of hops packets take from source to destination.
  • This metric provides an indication of the path length and routing efficiency in the network.

On the whole we had our simulation results for calculating network load and hop count in ns3 by measuring the amount of traffic carried by the network and the number of hops packets traverse between source and destination, respectively. Also, we provide more topics related to Network load and hop count.Network Load And Hop Count in ns3simulation project performance will be shared by our researchers, do you want to carry out network comparative analysis? Then stay in touch with us.