selective_repeat.cpp

//Simulating selective repeat sliding window protocol
#include <iostream>
#include <cstdlib>
using namespace std;
void receiver(int r);
int sent_packets=0;
int received_packets=0;
bool ack;
void sender()
{
	int buffer[10];
	for(int i=0;i<10;i++)
	{
		buffer[i]=sent_packets+1;
		sent_packets++;
		cout<<"sending packet "<<buffer[i]<<endl;
		receiver(buffer[i]);
		while(!ack)
		{
		 	cout<<"resending packet "<<buffer[i]<<endl;
		 	receiver(buffer[i]);
		}
	}
	if(sent_packets<200)
			sender();
}
void receiver(int r)
{
	int num=rand()%50;
	if(num>15)
	{
		cout<<"Received packet "<<r<<endl;
		received_packets++;
		ack=true;
	}
	else
	{
		ack=false;
		cout<<"error"<<endl;
	}
}
int main() {
	sender();
	return 0;
}