To implement an application layer in ns3, we need to execute the custom application in top of the network stack. These applications were mimic the characteristic of real world applications like file transfer, web servers or other custom interaction protocols.
The given below are the detailed procedures to make the custom application layer in ns3 tool:
Steps to Implement a Custom Application Layer in ns3
- Set Up Your ns3 Workspace: Make sure ns3 is installed in the computer.
- Create a New Module for the Application Layer:
- Navigate to the src directory of ns3 and create a new directory named custom-application.
- Inside the custom-application directory, create subdirectories: model, helper, and examples.
- Define the Application Layer Classes:
- In the model directory, create .cc and .h files for the application layer. Define the classes that simulate the behaviour of the application layer, such as CustomApplication.
- Implement the Application Layer Classes:
- Implement the key components of the application layer: session management, data generation, and communication logic.
- Generate classes for managing the application logic and network communication.
- Integrate the Application Layer with ns3 Network System:
- Use existing ns3 classes for basic transport layer communication.
- Register the custom application layer as a protocol in ns3.
- Create a Simulation Script:
- Set up a network topology.
- Download the Internet stack.
- To allow the application layer for custom application layer.
- Configure applications and execute the simulation.
Example Code Structure
The given below is the instances snippets for custom application layer in ns3:
- Define Custom Application Layer Classes
// src/custom-application/model/custom-application.h
#ifndef CUSTOM_APPLICATION_H
#define CUSTOM_APPLICATION_H
#include “ns3/application.h”
#include “ns3/address.h”
#include “ns3/ptr.h”
#include “ns3/socket.h”
#include “ns3/packet.h”
#include “ns3/traced-callback.h”
namespace ns3 {
class CustomApplication : public Application
{
public:
static TypeId GetTypeId (void);
CustomApplication ();
virtual ~CustomApplication ();
void Setup (Ptr<Socket> socket, Address address);
protected:
virtual void StartApplication (void);
virtual void StopApplication (void);
private:
void HandleRead (Ptr<Socket> socket);
void HandleSend (Ptr<Socket> socket, uint32_t available);
Ptr<Socket> m_socket;
Address m_peerAddress;
Ptr<Packet> m_packet;
};
} // namespace ns3
#endif // CUSTOM_APPLICATION_H
// src/custom-application/model/custom-application.cc
#include “custom-application.h”
#include “ns3/log.h”
#include “ns3/ipv4-address.h”
#include “ns3/socket-factory.h”
#include “ns3/packet.h”
namespace ns3 {
NS_LOG_COMPONENT_DEFINE (“CustomApplication”);
NS_OBJECT_ENSURE_REGISTERED (CustomApplication);
TypeId
CustomApplication::GetTypeId (void)
{
static TypeId tid = TypeId (“ns3::CustomApplication”)
.SetParent<Application> ()
.SetGroupName (“Applications”)
.AddConstructor<CustomApplication> ();
return tid;
}
CustomApplication::CustomApplication ()
{
NS_LOG_FUNCTION (this);
}
CustomApplication::~CustomApplication ()
{
NS_LOG_FUNCTION (this);
}
void
CustomApplication::Setup (Ptr<Socket> socket, Address address)
{
NS_LOG_FUNCTION (this << socket << address);
m_socket = socket;
m_peerAddress = address;
}
void
CustomApplication::StartApplication (void)
{
NS_LOG_FUNCTION (this);
m_socket->SetRecvCallback (MakeCallback (&CustomApplication::HandleRead, this));
m_socket->SetSendCallback (MakeCallback (&CustomApplication::HandleSend, this));
}
void
CustomApplication::StopApplication (void)
{
NS_LOG_FUNCTION (this);
if (m_socket)
{
m_socket->Close ();
}
}
void
CustomApplication::HandleRead (Ptr<Socket> socket)
{
NS_LOG_FUNCTION (this << socket);
Ptr<Packet> packet;
Address from;
while ((packet = socket->RecvFrom (from)))
{
NS_LOG_INFO (“Received ” << packet->GetSize () << ” bytes from ” << InetSocketAddress::ConvertFrom (from).GetIpv4 ());
}
}
void
CustomApplication::HandleSend (Ptr<Socket> socket, uint32_t available)
{
NS_LOG_FUNCTION (this << socket << available);
// Implement the logic to handle packet sending
}
} // namespace ns3
2. Define Custom Helper
// src/custom-application/helper/custom-application-helper.h
#ifndef CUSTOM_APPLICATION_HELPER_H
#define CUSTOM_APPLICATION_HELPER_H
#include “ns3/application-container.h”
#include “ns3/application-helper.h”
#include “ns3/custom-application.h”
namespace ns3 {
class CustomApplicationHelper : public ApplicationHelper
{
public:
CustomApplicationHelper (Address address);
ApplicationContainer Install (NodeContainer c) const;
ApplicationContainer Install (Ptr<Node> node) const;
private:
ObjectFactory m_factory;
Address m_address;
};
} // namespace ns3
#endif // CUSTOM_APPLICATION_HELPER_H
// src/custom-application/helper/custom-application-helper.cc
#include “custom-application-helper.h”
#include “ns3/custom-application.h”
#include “ns3/node.h”
#include “ns3/names.h”
namespace ns3 {
CustomApplicationHelper::CustomApplicationHelper (Address address)
{
m_factory.SetTypeId (CustomApplication::GetTypeId ());
m_address = address;
}
ApplicationContainer
CustomApplicationHelper::Install (NodeContainer c) const
{
ApplicationContainer apps;
for (NodeContainer::Iterator i = c.Begin (); i != c.End (); ++i)
{
apps.Add (Install (*i));
}
return apps;
}
ApplicationContainer
CustomApplicationHelper::Install (Ptr<Node> node) const
{
Ptr<CustomApplication> app = m_factory.Create<CustomApplication> ();
app->Setup (CreateObject<Socket> (), m_address);
node->AddApplication (app);
return ApplicationContainer (app);
}
} // namespace ns3
Example Simulation Script
Here, we have provided the sample script to complete the custom application layer in ns3:
// examples/custom-application-simulation.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”
#include “ns3/custom-application-helper.h”
using namespace ns3;
NS_LOG_COMPONENT_DEFINE (“CustomApplicationSimulation”);
int main (int argc, char *argv[])
{
CommandLine cmd;
cmd.Parse (argc, argv);
// Create nodes
NodeContainer nodes;
nodes.Create (4);
// Create point-to-point links
PointToPointHelper p2p;
p2p.SetDeviceAttribute (“DataRate”, StringValue (“1Gbps”));
p2p.SetChannelAttribute (“Delay”, StringValue (“2ms”));
NetDeviceContainer devices01 = p2p.Install (nodes.Get (0), nodes.Get (1));
NetDeviceContainer devices12 = p2p.Install (nodes.Get (1), nodes.Get (2));
NetDeviceContainer devices23 = p2p.Install (nodes.Get (2), nodes.Get (3));
NetDeviceContainer devices30 = p2p.Install (nodes.Get (3), nodes.Get (0));
// Install Internet stack
InternetStackHelper internet;
internet.Install (nodes);
// Assign IP addresses
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 interfaces30 = address.Assign (devices30);
// Create a custom application to receive packets
Address sinkAddress (InetSocketAddress (Ipv4Address::GetAny (), 8080));
CustomApplicationHelper customAppHelper (sinkAddress);
ApplicationContainer sinkApps = customAppHelper.Install (nodes.Get (0));
sinkApps.Start (Seconds (1.0));
sinkApps.Stop (Seconds (10.0));
// Create a custom application to send packets
Address clientAddress (InetSocketAddress (Ipv4Address (“10.1.1.1”), 8080));
OnOffHelper clientHelper (“ns3::TcpSocketFactory”, clientAddress);
clientHelper.SetAttribute(“OnTime”,StringValue(“ns3::ConstantRandomVariable[Constant=1]”)); clientHelper.SetAttribute(“OffTime”,StringValue(“ns3::ConstantRandomVariable[Constant=0]”));
clientHelper.SetAttribute (“DataRate”, DataRateValue (DataRate (“1Mbps”)));
clientHelper.SetAttribute (“PacketSize”, UintegerValue (1024));
ApplicationContainer clientApps = clientHelper.Install (nodes.Get (1));
clientApps.Start (Seconds (2.0));
clientApps.Stop (Seconds (10.0));
// Enable tracing
AsciiTraceHelper ascii;
p2p.EnableAsciiAll (ascii.CreateFileStream (“custom-application.tr”));
p2p.EnablePcapAll (“custom-application”);
// Run the simulation
Simulator::Run ();
Simulator::Destroy ();
return 0;
}
Running the Simulation
To run the simulation, compile the script and execute it:
./waf configure –enable-examples
./waf build
./waf –run custom-application-simulation
Overall, we had implemented the custom application layer on the top of the stack by using the ns3 simulator. We also offer the further information about custom application layer. Make use of our services to get best custom application layer in ns3 tool for your project.