How to Begin Implement Routing Interface Protocol in NS3

To begin implementing a routing interface protocol in NS3, we want to be mainly functioning with the Ipv4RoutingProtocol or Ipv6RoutingProtocol classes like a base. These classes permit for creating the custom routing behaviors and adding them to Internet stack of NS3. Below is a sequential methodology on how we can get started:

Steps to Begin Implement Routing Interface Protocol in NS3

Step 1: Understand Routing Protocol Requirements

1. What is a Routing Interface Protocol?
   • It directs how make a routing decisions and how packets are transmitted among the nodes.
   • It normally contains path selection, metrics calculation, and managing of control messages.
2. Key Elements:
   • Routing Tables: Sustain data regarding the routes to various destinations.
   • Protocol Logic: Describe how routes are determined, sustained, and updated.
   • Packet Forwarding: Execute the logic to manage the incoming and outgoing packets.

Step 2: Set Up NS3

1. Install NS3:
   • Clone the NS3 repository and construct it using:

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

cd ns-3-dev

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

./ns3 build

1. Verify Installation: Execute a basic example simulation script by confirming the set up:

./ns3 run examples/tutorial/first

Step 3: Plan the Routing Interface Protocol

1. Define the Protocol Goals:
   • Describe the objectives of routing interface protocol is distance-vector, link-state, or a hybrid protocol.
   • Define performance parameters which are leveraged for path selection such as hop count, delay, and bandwidth.
2. Interaction with NS3:
   • Protocol will be communicated with NS3’s Ipv4 or Ipv6 stack.
   • It needs to manage the route output for transmitting packets and route input for receiving packets.

Step 4: Create the Routing Protocol

Step 4.1: Define the Protocol Class

Make a new routing protocol class, which prolongs the Ipv4RoutingProtocol:

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

#include “ns3/node.h”

#include “ns3/socket.h”

using namespace ns3;

class MyRoutingProtocol : public Ipv4RoutingProtocol {

public:

static TypeId GetTypeId(void);

MyRoutingProtocol();

virtual ~MyRoutingProtocol();

// Override required methods

virtual Ptr<Ipv4Route> RouteOutput(Ptr<Packet> packet, const Ipv4Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) override;

virtual bool RouteInput(Ptr<const Packet> packet, const Ipv4Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) override;

private:

void UpdateRoutingTable();

void ProcessIncomingPacket(Ptr<Socket> socket);

};

Step 4.2: Implement Protocol Logic

• Routing Table Management:
  • Save routes to apply a map or a table structure.
  • Periodically modernize the routes or on receiving control messages.
• Packet Forwarding:
  • Execute the RouteOutput and RouteInput approaches for sending packet.

Ptr<Ipv4Route> MyRoutingProtocol::RouteOutput(Ptr<Packet> packet, const Ipv4Header &header,

Ptr<NetDevice> oif, Socket::SocketErrno &sockerr) {

// Implement routing table lookup logic here

Ptr<Ipv4Route> route = Create<Ipv4Route>();

// Set route fields (destination, source, gateway, etc.)

return route;

}

bool MyRoutingProtocol::RouteInput(Ptr<const Packet> packet, const Ipv4Header &header,

Ptr<const NetDevice> idev, UnicastForwardCallback ucb,

MulticastForwardCallback mcb, LocalDeliverCallback lcb,

ErrorCallback ecb) {

// Determine if the packet is for this node or needs forwarding

// Use callbacks to forward or deliver packets

return true;

}

Step 5: Integrate the Protocol into NS3

Step 5.1: Register the Protocol

Record the protocol using NS3’s TypeId system:

TypeId MyRoutingProtocol::GetTypeId(void) {

static TypeId tid = TypeId(“ns3::MyRoutingProtocol”)

.SetParent<Ipv4RoutingProtocol>()

.SetGroupName(“Internet”)

.AddConstructor<MyRoutingProtocol>();

return tid;

}

Step 5.2: Add to Nodes

Integrate the protocol to nodes within the simulation with InternetStackHelper:

#include “ns3/internet-stack-helper.h”

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

NodeContainer nodes;

nodes.Create(3);

InternetStackHelper stack;

Ptr<MyRoutingProtocol> myRouting = CreateObject<MyRoutingProtocol>();

stack.SetRoutingHelper(myRouting);  // Use your custom protocol

stack.Install(nodes);

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 6: Test and Debug

1. Simulation Setup:
   • Describe a network topology with the support of PointToPointHelper, CsmaHelper, or WifiHelper.
   • Set up traffic sources like OnOffApplication.
2. Use Tracing and Logging:
   • Make use of NS3 logging for debugging the protocol:

export NS_LOG=”MyRoutingProtocol=level_all|prefix_time”

./ns3 run my-simulation

1. Validate Behavior:
   • Examine the routing decisions and performance using FlowMonitor or packet tracing (PcapHelper) tools.

Step 7: Optimize and Document

1. Performance:
   • For scalability, enhance the route and modernize mechanisms.
   • Experiment the protocol including diverse network sizes and traffic loads.
2. Documentation:
   • Detail protocol design, assumptions, and restrictions.
   • It offers simulation scripts to simulate the outcomes for users.

Step 8: Extend the Protocol

• Integrate further protocol aspects such as:
  • Multi-path routing or load balancing.
  • Dynamic parameters such as link quality, congestion.
  • Incorporation including the mobility patterns for dynamic topologies.

We followed the delivered demonstration on how we can set up NS3 environment, create a routing protocol, implement and validate the behaviour by executing the Routing Interface Protocol and also we provided optimization and how to prolong this protocol using NS3 tool. We can also customize the implementation depends on your requirements.