How to Begin Implement Fastest Protocol in NS3

To start executing a Fastest Protocol in NS3 that has requires making a custom protocol which is intended for reducing end-to-end delay or enhancing for fast data delivery. It should be a transport-layer protocol, routing protocol, or even a MAC-layer protocol according to the objectives.

We follow these steps to start implementing custom “Fastest Protocol” in NS3.

Steps to Begin Implement Fastest Protocol in NS3

Step 1: Define Protocol Goals

We must describe the crucial aspects and objectives of the project, before jumping into implementation:

1. Layer of Operation: Define it function on the routing such as network layer, transport layer, or MAC layer.
2. Optimization Target:

• Reduce latency (end-to-end delay).
• Enhance bandwidth usage.
• Efficiently manage the congestion and retransmissions.

1. Scope:

• Decide on unicast or multicast.
• Static or dynamic topologies.

Step 2: Understand NS3 Architecture

• Learn the NS3 Layer Framework:
  • MAC Protocols: src/wifi/model/, src/csma/model/.
  • Transport Protocols: src/internet/model/tcp-socket.h, src/internet/model/udp-socket.h.
  • Routing Protocols: src/aodv/, src/olsr/.
• Study Related Protocols:
  • Explore AODV (routing) or TCP Tahoe (transport) for model inspiration.

Step 3: Set Up NS3 Development Environment

1. Create a Directory for the Protocol:
   • Make a protocol directory in src/, for sample src/fastest/.
2. Add Required Files:
   • fastest-protocol.h: Describe the structure of protocol and API.
   • fastest-protocol.cc: Execute the the protocol logic.
   • fastest-helper.h and fastest-helper.cc: For simulation scripts, we make a helper class.
3. Update Build System:
   • Fine-tune wscript in the src/ directory with new protocol.

Step 4: Design and Implement the Protocol

1. Define Protocol Class

According to the protocol’s layer, prolong the suitable NS3 base class:

• Prolong Ipv4RoutingProtocol for a routing protocol.
• For a transport protocol, expand the TcpSocket or UdpSocket.
• For a MAC protocol, it prolongs the NetDevice.

Example for a routing protocol:

#include “ns3/ipv4-routing-protocol.h”

#include “ns3/ipv4-address.h”

#include “ns3/timer.h”

class FastestRoutingProtocol : public ns3::Ipv4RoutingProtocol {

public:

static ns3::TypeId GetTypeId (void);

FastestRoutingProtocol ();

virtual ~FastestRoutingProtocol ();

// Override Ipv4RoutingProtocol methods

virtual ns3::Ptr<ns3::Ipv4Route> RouteOutput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<ns3::NetDevice> oif,

ns3::Socket::SocketErrno &sockerr);

virtual bool RouteInput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<const ns3::NetDevice> idev,

ns3::UnicastForwardCallback ucb,

ns3::MulticastForwardCallback mcb,

ns3::LocalDeliverCallback lcb,

ns3::ErrorCallback ecb);

// Fastest-specific methods

void UpdateRoutingTable ();

void SelectFastestPath (ns3::Ipv4Address dest);

private:

ns3::Ipv4Address m_selfAddress;

std::map<ns3::Ipv4Address, ns3::Ipv4Address> m_routingTable; // Destination -> Next hop

ns3::Timer m_updateTimer;

};

2. Implement Routing or Data Path Selection

• Choose the fastest path utilising performance parameters such as link delay, hop count, or throughput.

Example of path selection:

void FastestRoutingProtocol::SelectFastestPath (ns3::Ipv4Address dest) {

// Logic to calculate the fastest path to the destination

// Example: Dijkstra’s algorithm using link delay as the metric

}

3. Packet Handling

• Describe how packets are sent or executed.
• Make use of custom headers for more metadata as required.

Example:

void FastestRoutingProtocol::UpdateRoutingTable () {

// Periodically update the routing table based on delay metrics

}

bool FastestRoutingProtocol::RouteInput (

ns3::Ptr<const ns3::Packet> packet,

const ns3::Ipv4Header &header,

ns3::Ptr<const ns3::NetDevice> idev,

ns3::UnicastForwardCallback ucb,

ns3::MulticastForwardCallback mcb,

ns3::LocalDeliverCallback lcb,

ns3::ErrorCallback ecb) {

// Handle incoming packets

return true;

}

4. Timers and Events

For periodic updates or maintenance difficulties, we can utilize timers.

m_updateTimer.SetFunction(&FastestRoutingProtocol::UpdateRoutingTable, this);

m_updateTimer.Schedule(ns3::Seconds(1)); // Update every second

Step 5: Write a Helper Class

In simulation scripts, enable installation and setup of the protocol.

#include “fastest-routing-protocol.h”

class FastestHelper {

public:

void Install (ns3::NodeContainer nodes) {

for (auto it = nodes.Begin(); it != nodes.End(); ++it) {

ns3::Ptr<FastestRoutingProtocol> protocol = ns3::CreateObject<FastestRoutingProtocol>();

(*it)->AggregateObject(protocol);

}

}

};

Step 6: Write Simulation Script

Make a simulation script to experiment the performance of protocol.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “fastest-helper.h”

int main () {

ns3::NodeContainer nodes;

nodes.Create(10);

ns3::InternetStackHelper stack;

stack.Install(nodes);

FastestHelper fastestHelper;

fastestHelper.Install(nodes);

// Add traffic generators and sinks

ns3::Simulator::Run();

ns3::Simulator::Destroy();

return 0;

}

Step 7: Build and Test

1. Build the Code:

./waf configure

./waf build

1. Run Simulation:

./waf –run your-script

Step 8: Validate and Extend

• Validation:
  • Authenticate the protocol leveraging the performance parameters such as end-to-end delay, throughput, and packet delivery ratio.
  • Make use of NS3 tracing such as AsciiTraceHelper, PcapHelper to confirm the behavior.
• Extensions:
  • Integrate adaptive approaches, managing the dynamic network conditions.
  • Combine congestion control or QoS aspects for prioritized information.

We thoroughly executed and examined the Fastest Protocol that minimize latency (end-to-end delay), improve bandwidth usage and handle the congestion and retransmissions using NS3 tool in this guide. We can able to provide more comprehensive insights as requested.