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How to Calculate Network Fail over in ns3

To calculate the network failover in ns3 encompasses to simulate where a network component like link or node flops and then trace how well the network improves from this failure. The performance metrics for network failover are packet loss, latency, and time to recovery. If you are seeking guidance from experts to improve project performance, do not hesitate to contact our team of professionals.

The given below is the procedure on how to achieve this in ns3:

Steps to Calculate Network Failover

  1. Set Up the ns3 Environment:
    • Make sure ns3 is installed in the computer.
  2. Define the Network Topology:
    • Create a network topology with nodes and links.
  3. Install Applications:
    • Install traffic-generating applications on the nodes to simulate network traffic.
  4. Simulate a Network Failure:
    • Introduce a failure in the network by disabling a link or a node at a specific time.
  5. Monitor Performance Metrics:
    • Use trace sources or callbacks to monitor performance metrics before, during, and after the failure.
  6. Calculate Failover Metrics:
    • Measure the impact of the failure on the network and the time taken for the network to recover.

Example Code

Here, we provide the sample on how to setup a basic ns3 simulation to evaluate the network failover by defining the failure in a point-to-point network.

#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;

NS_LOG_COMPONENT_DEFINE (“NetworkFailoverExample”);

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

{

NS_LOG_UNCOND (“Packet received at ” << Simulator::Now ().GetSeconds () << ” seconds”);

}

void LinkFailureCallback ()

{

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

}

void CalculateFailoverTime ()

{

static Time lastPacketReceivedTime = Seconds (0);

static bool linkFailed = false;

static Time failoverStartTime;

Time now = Simulator::Now ();

if (linkFailed)

{

if (now – lastPacketReceivedTime > Seconds (1))

{

failoverStartTime = now;

linkFailed = false;

NS_LOG_UNCOND (“Failover started at ” << failoverStartTime.GetSeconds () << ” seconds”);

}

}

lastPacketReceivedTime = now;

Simulator::Schedule (Seconds (0.1), &CalculateFailoverTime);

}

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

{

CommandLine cmd;

cmd.Parse (argc, argv);

Time::SetResolution (Time::NS);

NodeContainer nodes;

nodes.Create (4);

PointToPointHelper pointToPoint;

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

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

NetDeviceContainer devices;

devices = 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)));

InternetStackHelper stack;

stack.Install (nodes);

Ipv4AddressHelper address;

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

address.Assign (devices);

// Create a UDP server on node 3

UdpServerHelper server (9);

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

serverApp.Start (Seconds (1.0));

serverApp.Stop (Seconds (20.0));

// Create a UDP client on node 0

UdpClientHelper client (Ipv4Address (“10.1.1.4”), 9);

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 (20.0));

// Trace packet receptions

Config::ConnectWithoutContext(“/NodeList/3/ApplicationList/*/$ns3::UdpServer/Rx”, MakeCallback (&PacketReceivedCallback));

// Simulate link failure

Simulator::Schedule (Seconds (5.0), &LinkFailureCallback);

devices.Get (1)->SetReceiveCallback (MakeNullCallback<bool, Ptr<NetDevice>, Ptr<const Packet>, uint16_t, const Address &> ());

Simulator::Schedule (Seconds (7.0), &CalculateFailoverTime);

Simulator::Stop (Seconds (20.0));

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

Explanation

  1. Setup: The code sets up a simple point-to-point network with four nodes connected in a line.
  2. Applications: A UDP server is installed on node 3, and a UDP client is installed on node 0 to generate traffic.
  3. Packet Reception Callback: The PacketReceivedCallback function logs the time each packet is received at the server.
  4. Link Failure Simulation: The LinkFailureCallback function is scheduled to simulate a link failure by disabling the receive callback of the second device (link between nodes 1 and 2) at 5 seconds.
  5. Failover Time Calculation: The CalculateFailoverTime function measures the time taken for the network to detect and recover from the failure by monitoring packet reception intervals.
  6. Simulation Control: The simulation runs for 20 seconds, allowing enough time to observe the network’s behavior before, during, and after the failure.

Running the Simulation

Compile and run the simulation using the following commands in your ns3 environment:

./waf configure

./waf build

./waf –run your-script-name

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

Here, we understand how to calculate the Network failover by using the performance metrics like packet loss, latency, and time to recovery then it evaluate how much it takes recover from failure using the ns3 tool. We also provide further information about how the network failover performs in other simulation tools. Please share all the details of your parameters related to Network Failover with ns3simulation.com, and we will furnish you with innovative results.