How to Begin Implement OSI Layer Protocol in NS3

To execute an OSI layer protocol using NS3 which encompasses to make functionality for a certain layer within the OSI model such as Physical Layer, Data Link Layer, Network Layer, Transport Layer, and so on within the NS3. Below is a stepwise approach to start executing a protocol for a certain OSI layer:

Steps to Begin Implement OSI Layer Protocol in NS3

Step 1: Understand NS3 and OSI Layers

• NS3 Basics: Make known about the modular architecture of NS3. Core modules such as Nodes, Devices, Channels, and Helpers are make backbone of NS3 simulations.
• Layer to Target: Choose we can execute which OSI layer like Physical Layer, Data Link Layer, Network Layer, Transport Layer, Application Layer.
• NS-3 Models: Know how NS3 replicates the existing layers:
  • Physical Layer: src/wifi/model/, src/point-to-point/
  • Data Link Layer: src/csma/model/, src/wifi/model/
  • Network Layer: src/internet/model/
  • Transport Layer: src/internet/model/tcp-socket.h, src/internet/model/udp-socket.h
  • Application Layer: src/applications/

Step 2: Define the Protocol Objectives

1. Layer-Specific Requirements:
   • Application Layer: High-level interaction such as HTTP, FTP, or DNS.
   • Physical Layer: It has modulation, coding, and error controlling.
   • Transport Layer: Reliable transmission, congestion control, and multiplexing.
   • Data Link Layer: It supports Medium access control (MAC), framing, and addressing.
   • Network Layer: Routing, packet forwarding, and IP addressing.
2. Protocol Features:
   • Indicate the protocol aspects that will be executed like packet processing, error handling, reliability, or security.

Step 3: Create a New Protocol

1. Create a Directory:
   • Make a protocol directory in src/. For instance, src/my-layer-protocol/.
2. Add Protocol Files:
   • my-layer-protocol.h: Header file for the protocol.
   • my-layer-protocol.cc: Execution file.
   • Alternatively, we can make helper classes such as my-layer-helper.h and my-layer-helper.cc.

Step 4: Implement Key Components

1. Define Protocol Class

Prolong the proper NS3 base class for the OSI layer. For instance:

• Physical Layer: Expand the NetDevice or make custom channel patterns.
• Data Link Layer: Execute MAC logic and prolong the NetDevice.
• Network Layer: It supports to develop Ipv4RoutingProtocol.
• Transport Layer: It expands the Socket.

Here’s a sample of Network Layer protocol:

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

#include “ns3/ipv4-address.h”

class MyNetworkProtocol : public ns3::Ipv4RoutingProtocol {

public:

static ns3::TypeId GetTypeId (void);

MyNetworkProtocol ();

virtual ~MyNetworkProtocol ();

// 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);

};

2. Implement Core Logic

• Packet Handling: Describe how packets are made, sent, and executed.
• Headers: Make custom headers to utilize ns3::Header for protocol.

Example for a custom header:

#include “ns3/header.h”

#include “ns3/mac48-address.h”

class MyProtocolHeader : public ns3::Header {

public:

static ns3::TypeId GetTypeId (void);

virtual TypeId GetInstanceTypeId () const;

void SetSrcAddress (ns3::Mac48Address addr);

void SetDstAddress (ns3::Mac48Address addr);

// Serialization and deserialization methods

virtual void Serialize (ns3::Buffer::Iterator start) const;

virtual uint32_t Deserialize (ns3::Buffer::Iterator start);

virtual void Print (std::ostream &os) const;

private:

ns3::Mac48Address m_src;

ns3::Mac48Address m_dst;

};

3. Simulate Channel Behavior (For Physical and Data Link Layers)

• Describe how signals broadcast among the nodes as functioning on the Physical Layer.
• We can prolong or utilize the existing channels like PointToPointChannel or WifiChannel.

4. Helper Classes

Make helper classes for incorporating the protocol to simulation scripts.

Example:

class MyProtocolHelper : public ns3::Object {

public:

void Install (ns3::NodeContainer nodes);

};

Step 5: Write a Simulation Script

Make a simulation test script to add protocol including NS3 nodes and then replicate a network scenario.

Example:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “my-layer-helper.h”

int main () {

ns3::NodeContainer nodes;

nodes.Create (2);

MyProtocolHelper myProtocolHelper;

myProtocolHelper.Install (nodes);

ns3::Simulator::Run ();

ns3::Simulator::Destroy ();

return 0;

}

Step 6: Build and Test

1. Build the Code:

./waf configure

./waf build

1. Run the Simulation:

./waf –run your-simulation-script

1. Validate Results:
   • Record all events to leverage the NS3 tracing as AsciiTraceHelper, PcapHelper.
   • For debugging, we can use NS_LOG to make sure that protocol logic properly functions if expected.

Step 7: Validate and Extend

• Metrics: Estimate the performance parameters such as throughput, delay, or packet delivery ratio.
• Features: Integrate further aspects like congestion control, error detection, or multi-path routing.

Step 8: Document and Publish

• Document Code: Define the protocol design and logic using comments and markdown.
• Share Results: Print the protocol including use cases, replications, and performance analysis.

These set up walk you via overall implementation and analysis process of OSI Layer Protocol using NS3 environment.  Based on your needs we will present in-depth details and advance execution in another manual.