How to Begin Implement Network NTP Management in NS3

To implement the Network Time Protocol (NTP) Management in ns3 has includes the replicate a synchronization for duration with devices in network for using the NTP server. The aim is to design the request-response behavior for NTP and examine its effect of network performance.

Here’s how to begin implementing network NTP management in ns-3:

Steps to Begin Implement Network NTP Management in NS3

1. Understand NTP Management

• NTP Components:
  • NTP Server: Delivers for accurate time to clients.
  • NTP Clients: Request and coordinate the duration from a server.
• NTP Mechanism:
  • Request: Clients transmit the requests for server in the present time.
  • Response: The server forward the current time.
  • Clients alter their clocks according to the received response for estimate the delay.

2. Set up ns-3 Environment

• Install ns-3:

git clone https://gitlab.com/nsnam/ns-3-dev.git

cd ns-3-dev

./ns3 configure –enable-examples –enable-tests

./ns3 build

• Verify the setup:

./ns3 run hello-simulator

3. Design the NTP Management Simulation

• Scenario:
  • It replicates a various NTP server and clients.
  • Clients are periodically requested the duration for bring up-to-date from the server.
• Network Topology:
  • NTP Server: The central node has delivers the time synchronization.
  • Clients: The several nodes are enquiring the server.

4. Steps to Implement NTP Management

(a) Create Nodes

• Describe the nodes for the NTP server and clients:

NodeContainer ntpServer, ntpClients;

ntpServer.Create(1);  // Single NTP server

ntpClients.Create(3); // Three NTP clients

(b) Set Up Network Links

• PointToPointHelper or CsmaHelper used to linked the nodes:

PointToPointHelper p2p;

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

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

NetDeviceContainer devices;

for (uint32_t i = 0; i < ntpClients.GetN(); ++i) {

devices.Add(p2p.Install(NodeContainer(ntpServer.Get(0), ntpClients.Get(i))));

}

(c) Install Internet Stack

• Install the Internet stack for all nodes:

InternetStackHelper stack;

stack.Install(ntpServer);

stack.Install(ntpClients);

(d) Assign IP Addresses

• Allot the IP addresses for all devices:

Ipv4AddressHelper address;

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

address.Assign(devices);

5. Implement NTP Communication

(a) NTP Server Application

• Generate the NTP server application which listens for time requests and responds:

class NtpServerApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress localAddress(Ipv4Address::GetAny(), 123); // NTP port

socket->Bind(localAddress);

socket->SetRecvCallback(MakeCallback(&NtpServerApp::HandleRequest, this));

}

void HandleRequest(Ptr<Socket> socket) {

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

NS_LOG_UNCOND(“Received NTP request at ” << Simulator::Now().GetSeconds() << ” seconds”);

// Create NTP response with simulated timestamp

Ptr<Packet> responsePacket = Create<Packet>(sizeof(double));

double currentTime = Simulator::Now().GetSeconds();

responsePacket->AddAtEnd(Create<Buffer>(&currentTime, sizeof(currentTime)));

socket->Send(responsePacket);

NS_LOG_UNCOND(“Sent NTP response with time: ” << currentTime << ” seconds”);

}

};

Ptr<NtpServerApp> ntpServerApp = CreateObject<NtpServerApp>();

ntpServer.Get(0)->AddApplication(ntpServerApp);

ntpServerApp->SetStartTime(Seconds(1.0));

ntpServerApp->SetStopTime(Seconds(10.0));

(b) NTP Client Application

• Make an NTP client application which periodically transmit the duration requests:

class NtpClientApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress serverAddress(Ipv4Address(“10.1.1.1”), 123); // NTP server address

socket->Connect(serverAddress);

// Schedule periodic requests

Simulator::Schedule(Seconds(2.0), &NtpClientApp::SendRequest, this, socket);

}

void SendRequest(Ptr<Socket> socket) {

Ptr<Packet> requestPacket = Create<Packet>(sizeof(double));

double clientTime = Simulator::Now().GetSeconds();

requestPacket->AddAtEnd(Create<Buffer>(&clientTime, sizeof(clientTime)));

socket->Send(requestPacket);

NS_LOG_UNCOND(“Sent NTP request at: ” << clientTime << ” seconds”);

// Schedule the next request

Simulator::Schedule(Seconds(2.0), &NtpClientApp::SendRequest, this, socket);

}

};

for (uint32_t i = 0; i < ntpClients.GetN(); ++i) {

Ptr<NtpClientApp> ntpClientApp = CreateObject<NtpClientApp>();

ntpClients.Get(i)->AddApplication(ntpClientApp);

ntpClientApp->SetStartTime(Seconds(1.0));

ntpClientApp->SetStopTime(Seconds(10.0));

}

6. Monitor and Analyze NTP Traffic

• Use FlowMonitor for examine the congestion of NTP:

FlowMonitorHelper flowmon;

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

Simulator::Run();

monitor->SerializeToXmlFile(“ntp-traffic.xml”, true, true);

• Log requests and responses for debugging:

NS_LOG_UNCOND(“NTP request/response at: ” << Simulator::Now().GetSeconds() << ” seconds”);

7. Complete Example Code

Here is a comprehensive sample for replicate a NTP management:

#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;

class NtpServerApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress localAddress(Ipv4Address::GetAny(), 123);

socket->Bind(localAddress);

socket->SetRecvCallback(MakeCallback(&NtpServerApp::HandleRequest, this));

}

void HandleRequest(Ptr<Socket> socket) {

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

NS_LOG_UNCOND(“Received NTP request at ” << Simulator::Now().GetSeconds() << ” seconds”);

Ptr<Packet> responsePacket = Create<Packet>(sizeof(double));

double currentTime = Simulator::Now().GetSeconds();

responsePacket->AddAtEnd(Create<Buffer>(&currentTime, sizeof(currentTime)));

socket->Send(responsePacket);

NS_LOG_UNCOND(“Sent NTP response with time: ” << currentTime << ” seconds”);

}

};

class NtpClientApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress serverAddress(Ipv4Address(“10.1.1.1”), 123);

socket->Connect(serverAddress);

Simulator::Schedule(Seconds(2.0), &NtpClientApp::SendRequest, this, socket);

}

void SendRequest(Ptr<Socket> socket) {

Ptr<Packet> requestPacket = Create<Packet>(sizeof(double));

double clientTime = Simulator::Now().GetSeconds();

requestPacket->AddAtEnd(Create<Buffer>(&clientTime, sizeof(clientTime)));

socket->Send(requestPacket);

NS_LOG_UNCOND(“Sent NTP request at: ” << clientTime << ” seconds”);

Simulator::Schedule(Seconds(2.0), &NtpClientApp::SendRequest, this, socket);

}

};

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

CommandLine cmd;

cmd.Parse(argc, argv);

NodeContainer ntpServer, ntpClients;

ntpServer.Create(1);

ntpClients.Create(3);

PointToPointHelper p2p;

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

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

NetDeviceContainer devices;

for (uint32_t i = 0; i < ntpClients.GetN(); ++i) {

devices.Add(p2p.Install(NodeContainer(ntpServer.Get(0), ntpClients.Get(i))));

}

InternetStackHelper stack;

stack.Install(ntpServer);

stack.Install(ntpClients);

Ipv4AddressHelper address;

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

address.Assign(devices);

Ptr<NtpServerApp> ntpServerApp = CreateObject<NtpServerApp>();

ntpServer.Get(0)->AddApplication(ntpServerApp);

ntpServerApp->SetStartTime(Seconds(1.0));

ntpServerApp->SetStopTime(Seconds(10.0));

for (uint32_t i = 0; i < ntpClients.GetN(); ++i) {

Ptr<NtpClientApp> ntpClientApp = CreateObject<NtpClientApp>();

ntpClients.Get(i)->AddApplication(ntpClientApp);

ntpClientApp->SetStartTime(Seconds(1.0));

ntpClientApp->SetStopTime(Seconds(10.0));

}

FlowMonitorHelper flowmon;

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

Simulator::Run();

monitor->SerializeToXmlFile(“ntp-traffic.xml”, true, true);

Simulator::Destroy();

return 0;

}

8. Validate and Extend

• It justifies the NTP requests and responses for using the records or the FlowMonitor output.
• Encompass the functionality:
  • Enhance the jitter or delay for realism.
  • It replicates the NTP attacks for sample spoofing or DDoS.
  • It improves the secure for NTP features.

We thorough the manual and provide the valuable insights regarding how to calculate the Network Time Protocol in ns3 tool. Advance details concerning the implementation of the Network Time Protocol in different simulations will be provided.