3. Write a program to simulate Go back N and Selective Repeat Modes of Sliding Window Protocol in peer to peer mode and demonstrate the packets captured traces using Wireshark Packet Analyzer Tool for peer to peer mode.

Download The write up here

//-----AT CLIENT SIDE------
    
    import java.lang.System;
    import java.net.*;
    import java.io.*;
    
    public class Client {
        static Socket connection;
    
        public static void main(String a[]) throws SocketException {
            try {
                int v[] = new int[9];
                //int g[] = new int[8];
                int n = 0;
                InetAddress addr = InetAddress.getByName("Localhost");
                System.out.println(addr);
                connection = new Socket(addr, 8011);
                DataOutputStream out = new DataOutputStream(
                        connection.getOutputStream());
                DataInputStream in = new DataInputStream(
                        connection.getInputStream());
                int p = in.read();
                System.out.println("No of frame is:" + p);
    
                for (int i = 0; i < p; i++) {
                    v[i] = in.read();
                    System.out.println(v[i]);
                    //g[i] = v[i];
                }
                v[5] = -1;
                for (int i = 0; i < p; i++)
                 {
                    System.out.println("Received frame is: " + v[i]);
    
                    }
                for (int i = 0; i < p; i++)
                    if (v[i] == -1) {
                System.out.println("Request to retransmit packet no "
                                + (i+1) + " again!!");
                        n = i;
                        out.write(n);
                        out.flush();
                    }
    
                System.out.println();
               
                    v[n] = in.read();
                System.out.println("Received frame is: " + v[n]);
               
               
    
                System.out.println("quiting");
            } catch (Exception e) {
                System.out.println(e);
            }
    
        }
    }
      
/* OUTPUT 
iotlab@iotlab-Veriton-M200-B360:~/sliding window$ javac Client.java
iotlab@iotlab-Veriton-M200-B360:~/sliding window$ java Client
Localhost/127.0.0.1
No of frame is:9
30
40
50
60
70
80
90
100
110
Received frame is: 30
Received frame is: 40
Received frame is: 50
Received frame is: 60
Received frame is: 70
Received frame is: -1
Received frame is: 90
Received frame is: 100
Received frame is: 110
Request to retransmit packet no 6 again!!

Received frame is: 80
quiting
iotlab@iotlab-Veriton-M200-B360:~/sliding window$
*/


//-----AT SERVER SIDE-----
   
    import java.io.DataInputStream;
    import java.io.DataOutputStream;
    import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.net.SocketException;
   
    public class Server {
        static ServerSocket Serversocket;
        static DataInputStream dis;
        static DataOutputStream dos;
   
        public static void main(String[] args) throws SocketException {
   
        try {
            int a[] = { 30, 40, 50, 60, 70, 80, 90, 100, 110 };
            Serversocket = new ServerSocket(8011);
            System.out.println("waiting for connection");
            Socket client = Serversocket.accept();
            dis = new DataInputStream(client.getInputStream());
            dos = new DataOutputStream(client.getOutputStream());
            System.out.println("The number of packets sent is:" + a.length);
            int y = a.length;
            dos.write(y);
            dos.flush();
   
            for (int i = 0; i < a.length; i++) {
                dos.write(a[i]);
                dos.flush();
            }
   
            int k = dis.read();
   
            dos.write(a[k]);
            dos.flush();
   
            } catch (IOException e) {
                System.out.println(e);
            } finally {
                try {
                    dis.close();
                    dos.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
   
            }
        }
    }

/*OUTPUT
iotlab@iotlab-Veriton-M200-B360:~/sliding window$ javac Server.java
iotlab@iotlab-Veriton-M200-B360:~/sliding window$ java Server
waiting for connection
The number of packets sent is:9
iotlab@iotlab-Veriton-M200-B360:~/sliding window$
*/