How to Implement Network Disaster Recovery in ns3

To implement the Network Disaster Recovery (NDR) in ns3, we have to recover from failures or disasters by creating a network simulation which includes strategies like redundant paths, backup servers, data replication, and automated failover mechanisms.

Here, we provide a step-by-step guide to help you implement a simple NDR mechanism in ns3:

Step-by-Step Implementation:

Step 1: Set Up ns3 Environment

1. Install ns3: Make sure that you have installed the ns3 on your computer.
2. Familiarize Yourself with ns3: Read through the ns3 tutorial to comprehend the basic concepts and structure of ns3 simulations.

Step 2: Define the Network Topology

1. Create a Redundant Network Topology: We have to state the network topology that has redundant paths and backup servers. This involves creating multiple nodes, setting up channels, and configuring IP addresses. We’ll use a simple topology with primary and backup paths.

Step 3: Implement Disaster Recovery Mechanism

To implement a basic NDR mechanism, we can use the following strategies:

1. Redundant Paths: Create multiple paths in the middle of the source and destination.
2. Automated Failover: Suppose the primary path fails, we have to link to a backup path.
3. Data Replication: To make sure the data availability by copy them in the backup servers.

Follow the provided sample to implement a simple NDR mechanism:

C++ Code for ns3 Simulation (main.cc)

#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;

class DisasterRecoveryApp : public Application

{

public:

DisasterRecoveryApp() {}

virtual ~DisasterRecoveryApp() {}

void Setup(Address primaryAddress, Address backupAddress, uint16_t port)

{

m_primaryAddress = primaryAddress;

m_backupAddress = backupAddress;

m_peerPort = port;

m_usePrimary = true;

}

void Failover()

{

m_usePrimary = false;

std::cout << “Failover to backup path.” << std::endl;

}

private:

virtual void StartApplication()

{

m_socket = Socket::CreateSocket(GetNode(), TypeId::LookupByName(“ns3::UdpSocketFactory”));

m_socket->Bind();

ConnectToPeer();

// Schedule the first packet transmission

Simulator::Schedule(Seconds(1.0), &DisasterRecoveryApp::SendPacket, this);

// Set up the receive callback

m_socket->SetRecvCallback(MakeCallback(&DisasterRecoveryApp::ReceivePacket, this));

}

virtual void StopApplication()

{

if (m_socket)

{

m_socket->Close();

m_socket = 0;

}

}

void ConnectToPeer()

{

if (m_usePrimary)

{

m_socket->Connect(InetSocketAddress(m_primaryAddress, m_peerPort));

}

else

{

m_socket->Connect(InetSocketAddress(m_backupAddress, m_peerPort));

}

}

void SendPacket()

{

std::string message = “Test message”;

Ptr<Packet> packet = Create<Packet>((uint8_t *)message.c_str(), message.size());

m_socket->Send(packet);

// Schedule the next packet transmission

Simulator::Schedule(Seconds(1.0), &DisasterRecoveryApp::SendPacket, this);

}

void ReceivePacket(Ptr<Socket> socket)

{

Ptr<Packet> packet = socket->Recv();

// Simulate a failure detection mechanism

if (m_usePrimary && Simulator::Now().GetSeconds() > 10.0)

{

Failover();

ConnectToPeer();

}

// Print received message (for demonstration purposes)

uint8_t buffer[1024];

packet->CopyData(buffer, packet->GetSize());

std::string receivedMessage((char *)buffer, packet->GetSize());

std::cout << “Received message: ” << receivedMessage << std::endl;

}

Ptr<Socket> m_socket;

Address m_primaryAddress;

Address m_backupAddress;

uint16_t m_peerPort;

bool m_usePrimary;

};

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

{

NodeContainer nodes;

nodes.Create(4); // Example: 4 nodes (1 client, 1 primary server, 1 backup server, 1 router)

PointToPointHelper pointToPoint;

pointToPoint.SetDeviceAttribute(“DataRate”, StringValue(“1Gbps”));

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

NetDeviceContainer devices1 = pointToPoint.Install(nodes.Get(0), nodes.Get(3)); // Client to Router

NetDeviceContainer devices2 = pointToPoint.Install(nodes.Get(3), nodes.Get(1)); // Router to Primary Server

NetDeviceContainer devices3 = pointToPoint.Install(nodes.Get(3), nodes.Get(2)); // Router to Backup Server

InternetStackHelper stack;

stack.Install(nodes);

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);

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

Ipv4InterfaceContainer interfaces3 = address.Assign(devices3);

Ipv4GlobalRoutingHelper::PopulateRoutingTables();

uint16_t port = 9;

Ptr<DisasterRecoveryApp> clientApp = CreateObject<DisasterRecoveryApp>();

clientApp->Setup(interfaces2.GetAddress(1), interfaces3.GetAddress(1), port);

nodes.Get(0)->AddApplication(clientApp);

clientApp->SetStartTime(Seconds(2.0));

clientApp->SetStopTime(Seconds(20.0));

Simulator::Run();

Simulator::Destroy();

return 0;

}

Explanation

1. Network Topology:
   • The network consists of 4 nodes: a client, a primary server, a backup server, and a router.
   • The packets are forward to the primary server or the backup server by the router which is linked to the client.
2. DisasterRecoveryApp Class:
   • This custom application class handles sending, receiving, and failover mechanisms.
   • Use Setup method to initialize an application that contains primary and backup server addresses and the port.
   • StartApplication method sets up the socket connection, schedules packet transmission, and sets up the receive callback.
   • Sockets are linked to the primary server or backup server with the help of ConnectToPeer method.
   • SendPacket method sends a message to the connected server.
   • ReceivePacket method receives a message, simulates a failure detection mechanism, and triggers failover if needed.
   • Failover method shifts the linking to the backup server.
3. Main Function:
   • Creates a network with 4 nodes organised with point-to-point links.
   • Allocates IP addresses for the nodes.
   • Initializes the DisasterRecoveryApp application on the client node.
   • The client sends packets to the primary server. If a failure is detected (simulated after 10 seconds), it switches to the backup server.

Compile and Run

1. Compile the Code: Compile the ns3 simulation code using the following command:

g++ -std=c++11 -o ns3-disaster-recovery main.cc `pkg-config –cflags –libs ns3-dev`

1. Run the Simulation: Execute the compiled program:

./ns3-disaster-recovery

This setup demonstrates a simple implementation of network disaster recovery in ns3. You can expand it further to include more sophisticated failover mechanisms, additional nodes, and more complex network topologies as needed.

In conclusion, this provided demonstration walk you through the process on how to implement the network disaster recovery in the ns3 tool. we also offer the related implantation support for your project work on this topic as per your need.