How to Implement Fastest Protocol in NS2

To implement the “faster” protocol in ns2, we have to enhance an existing protocol or develop a new protocol focused at decreasing latency or improving throughput in a network. The facts of what you mean by “fastest” can change, so we will demonstrate a common technique to generate a protocol that prioritizes speed like routing protocol developed to select the shortest (or fastest) path depends on latency.

In the below procedure, we provided the basic simulation of fastest protocol in ns2:

Step-by-Step Implementation:

Step 1: Define the Protocol’s Objectives

First, clearly state what “fastest” means for your protocol:

  • Minimizing Latency: The protocol might aim on choosing paths with the minimal latency.
  • Maximizing Throughput: Alternatively, it could intend to increase the data rate across the network.
  • Quick Route Discovery: It might prioritize finding and accomplishing routes as fast as possible.

Step 2: Set Up NS2

Make certain to install the ns2 and correct their configuration depends on you operating system. Due to the ns2 supports customizable protocols, we can build on available ones like AODV, DSR or OLSR and alter them to enhance for speed.

Step 3: Implement the Fastest Protocol in C++

Let’s assume you want to generate a protocol that dynamically picks the lowest-latency path amongst nodes.

  1. Create the Fastest Protocol Agent Class

Here’s a basic structure for implementing a protocol that aims to decrease latency:

#include <agent.h>

#include <packet.h>

#include <trace.h>

#include <address.h>

#include <map>

class FastestAgent : public Agent {

public:

FastestAgent();

void recv(Packet* p, Handler* h);

void sendRouteRequest(int dest);

void handleRouteReply(Packet* p);

void forwardPacket(Packet* p);

void updateRoutingTable(int dest, int nextHop, double latency);

protected:

std::map<int, std::pair<int, double>> routingTable_; // Destination -> (Next Hop, Latency)

};

// Constructor

FastestAgent::FastestAgent() : Agent(PT_UDP) {

// Initialization code here

}

// Packet reception

void FastestAgent::recv(Packet* p, Handler* h) {

hdr_ip* iph = hdr_ip::access(p);

if (iph->daddr() == addr()) {

// Packet is for this node; process it

} else if (iph->ttl() <= 0) {

// Drop packet if TTL has expired

drop(p);

} else {

// Forward the packet using the routing table

forwardPacket(p);

}

}

// Send a route request to discover the fastest path

void FastestAgent::sendRouteRequest(int dest) {

Packet* p = allocpkt();

hdr_cmn* cmnh = hdr_cmn::access(p);

cmnh->ptype() = PT_ROUTE_REQUEST;

// Set source and destination addresses

hdr_ip* iph = hdr_ip::access(p);

iph->saddr() = addr();

iph->daddr() = dest;

cmnh->size() = sizeof(hdr_cmn) + sizeof(hdr_ip);

// Broadcast the route request

send(p, 0);

}

// Handle incoming route replies

void FastestAgent::handleRouteReply(Packet* p) {

hdr_ip* iph = hdr_ip::access(p);

int src = iph->saddr();

double latency = Scheduler::instance().clock() – iph->send_time(); // Calculate latency

// Update the routing table with the lower latency path

updateRoutingTable(src, addr(), latency);

}

// Update the routing table with a new route

void FastestAgent::updateRoutingTable(int dest, int nextHop, double latency) {

if (routingTable_.find(dest) == routingTable_.end() || routingTable_[dest].second > latency) {

routingTable_[dest] = std::make_pair(nextHop, latency);

}

}

// Forward a packet using the fastest route

void FastestAgent::forwardPacket(Packet* p) {

hdr_ip* iph = hdr_ip::access(p);

int dest = iph->daddr();

if (routingTable_.find(dest) != routingTable_.end()) {

int nextHop = routingTable_[dest].first;

send(p, nextHop);

} else {

// Send a route request if no route is found

sendRouteRequest(dest);

}

}

  1. Define Packet Types and Structures

You might need to state custom packet kinds for route requests and replies:

#define PT_FASTEST_ROUTE_REQUEST 52

#define PT_FASTEST_ROUTE_REPLY 53

// Add this to the packet.h file in NS2’s source code

packet_t PT_FASTEST_ROUTE_REQUEST;

packet_t PT_FASTEST_ROUTE_REPLY;

Identify the packet types by altering the ns-default.tcl.

  1. Integrate the Protocol into NS2
  1. Modify the Makefile: Attach your new FastestAgent class to the NS2 Makefile so that it gets compiled with the remains of the simulator.
  2. Recompile NS2:

make clean

make

Step 4: Create a Tcl Script to Simulate the Fastest Protocol

Generate a TCL script to replicate a network using this protocol, after the compilation is done.

Example Tcl Script:

# Create a simulator object

set ns [new Simulator]

# Define the topology

set val(chan)   Channel/WiredChannel

set val(ll)     LL

set val(ifq)    Queue/DropTail/PriQueue

set val(ifqlen) 50

set val(stop)   100.0

# Initialize the topology object

set topo [new Topography]

$topo load_flatgrid 500 500

# Create nodes

set node1 [$ns node]

set node2 [$ns node]

set node3 [$ns node]

# Establish links between nodes

$ns duplex-link $node1 $node2 10Mb 10ms DropTail

$ns duplex-link $node2 $node3 10Mb 5ms DropTail

# Attach Fastest agents to nodes

set fastest1 [new Agent/FastestAgent]

set fastest2 [new Agent/FastestAgent]

set fastest3 [new Agent/FastestAgent]

$ns attach-agent $node1 $fastest1

$ns attach-agent $node2 $fastest2

$ns attach-agent $node3 $fastest3

# Set up traffic sources and sinks

set udp [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $node1 $udp

$ns attach-agent $node3 $null

$ns connect $udp $null

# Start sending data from node 1 to node 3

$ns at 0.0 “$udp start”

# Simulation end

$ns at $val(stop) “stop”

$ns at $val(stop) “exit 0”

proc stop {} {

global ns

$ns flush-trace

exit 0

}

# Run the simulation

$ns run

Step 5: Run the Simulation

  1. Save the Tcl script (fastest_protocol_simulation.tcl).
  2. Open a terminal and navigate to the directory where you logged the Tcl script.
  3. Execute the simulation using the given command:

ns fastest_protocol_simulation.tcl

Step 6: Analyze the Results

  • Evaluate the protocol’s performance in terms of metrics includes packet delivery time, latency, and routing efficiency by using trace files and the network animator (NAM).
  • Assess how effectively the protocol picks and upholds the fastest routes in the network.

Additional Considerations

  • Scalability: Compute its scalability by examining the protocol in larger networks with more nodes.
  • Optimization: Consider executing optimizations like caching route replies or predicting route performance depends on historical data.
  • Mobility: Simulate mobility situations to see how the protocol adapts to varying network conditions.

In conclusion, we have aggregated the information and present them as a step-by-step format for you to implement the Faster Protocol in the ns2 tool. You can also extend the simulation for optimization purposes. If needed, we can give you its advanced features and how to include them.

Get assistance with implementing Fastest Protocol in NS2, along with topic support, feel free to reach out to us for optimal results.