DCN Record Vel(4)

DEPARTMENT OF COMPUTER SCIENCE Page No

One Way Communication Using Server Socket

SERVER:

import java.io.*;import java.net.*;class onewayserver{public static void main(String args[]) throws IOException{try{String x;InputStreamReader inpst=new InputStreamReader(System.in);BufferedReader bufred=new BufferedReader(inpst);ServerSocket sersoc=new ServerSocket(3000);Socket soc=sersoc.accept();System.out.println("\n\t\tServer Window");System.out.println("\nServer Client Connection was Established");OutputStream outst=soc.getOutputStream();DataOutputStream doutst=new DataOutputStream(outst);System.out.println("\nEnter the Message ---> Type End to Exit");while(true){x=bufred.readLine();if(x.equalsIgnoreCase("End"))break;dos.writeUTF(x);}}catch(Exception e){}}}

KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


CLIENT:

import java.io.*;import java.net.*;class onewayclient{public static void main(String args[]) throws IOException{try{Socket soc=new Socket("LocalHost",3000);InputStream inpst=soc.getInputStream();DataInputStream din=new DataInputStream(inpst);System.out.println("\n Received from Server");while(true){System.out.println(din.readUTF());}}catch(Exception e){}}}



SCREENSHOT :

Server Window

Client Window



Two Way Communication Using Server Socket

SERVER:

import java.io.*;import java.net.*;class tcp_twowayserver{public static void main(String args[]){try{String str;ServerSocket sersoc=new ServerSocket(2000);Socket soc=sersoc.accept();BufferedReader bufred=new BufferedReader(new InputStreamReader(System.in));InputStream inpst=soc.getInputStream();DataInputStream dinpst=new DataInputStream(inpst);OutputStream outst=soc.getOutputStream();DataOutputStream doutst=new DataOutputStream(outst);System.out.println("\t\tSERVER WINDOW");while(true){System.out.println("TO CLIENT ENTER THE STRING:");str=bufred.readLine();if(str.equalsIgnoreCase("end"))break;dos.writeUTF(str);System.out.println("\t\tFROM CLIENT");System.out.println(dinpst.readUTF());}}catch(IOException e){System.out.println("CLIENT TERMINATED");}}}



CLIENT:

import java.io.*;import java.net.*;class tcp_twowayclient{public static void main(String args[])throws IOException{try{String str;Socket soc=new Socket("127.0.0.1",2000);BufferedReader bufred=new BufferedReader(new InputStreamReader(System.in));InputStream inpst=soc.getInputStream();DataInputStream dinpst=new DataInputStream(inpst);OutputStream outst=soc.getOutputStream();DataOutputStream doutst=new DataOutputStream(outst);System.out.println("\t\tCLIENT WINDOW");while(true){System.out.println("\t\tFROM SERVER:");System.out.println(dinpst.readUTF());System.out.println("\t\t TO SERVER ENTER THE STRING:");str=bufred.readLine();if(str.equalsIgnoreCase("end"))break;doutst.writeUTF(str);}}catch(IOException e){System.out.println("SERVER TERMINATED");}}}

SCREENSHOT : KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


Server Window

Client Window

One Way Communication Using User-Datagram Protocol(UDP)



SERVER:

import java.io.*;import java.net.*;class dgm_onewayserver{public static void main(String args[])throws IOException{try{int cport=999;int sport=666;String s;DatagramSocket datasoc=new DatagramSocket(sport);InputStreamReader inpstr=new InputStreamReader(System.in);BufferedReader bufred=new BufferedReader(inpstr);System.out.println("ENTER THE MESSAGE:");while(true){s=bufred.readLine();byte b[]=s.getBytes();InetAddress iadd=InetAddress.getLocalHost();DatagramPacket datapac=new DatagramPacket(b,b.length,iadd,cport);datasoc.send(datapac);if(s.equalsIgnoreCase("end"))break;}}catch(Exception e){e.printStackTrace();}}}

CLIENT:



import java.io.*;import java.net.*;class dgm_onewayclient{public static void main(String args[])throws IOException{try{int cport=999;int sport=666;byte b[]=new byte[100];DatagramSocket datasoc=new DatagramSocket(cport);while(true){DatagramPacket datapac=new DatagramPacket(b,b.length);datasoc.receive(datapac);String s=new String(datapac.getData(),0,datapac.getLength());System.out.println("FROM SERVER:");System.out.println(s);if(s.equalsIgnoreCase("end")){System.exit(0);}}}catch(Exception e){e.printStackTrace();}}}

SCREENSHOT :

Server Window KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


Client Window

Two Way Communication Using User-Datagram Protocol(UDP)

SERVER:



import java.io.*;import java.net.*;class dgm_twowayserver{public static void main(String args[])throws IOException{System.out.println("SERVER WINDOW");while(true){try{int cport=2010;InputStreamReader inpstr=new InputStreamReader(System.in);BufferedReader bufred=new BufferedReader(inpstr);System.out.println("TO CLIENT, ENTER YOUR MESSAGE:");String s=bufred.readLine();byte b[]=s.getBytes();InetAddress iadd=InetAddress.getByName("LocalHost");DatagramSocket datasoc=new DatagramSocket();DatagramPacket datapac=new DatagramPacket(b,b.length,iadd,2010);datasoc.send(datapac);datasoc.close();if(s.equalsIgnoreCase("end"))break;//TO RECEIVEint sport=2000;byte b1[]=new byte[100];DatagramSocket datasoc1=new DatagramSocket(2000);DatagramPacket datapac1=new DatagramPacket(b1,b1.length);datasoc1.receive(datapac1);String s1=new String(datapac1.getData(),0,datapac1.getLength());System.out.println("FROM CLIENT");

System.out.println(s1);datasoc1.close();} KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


catch(IOException e){System.out.println("CLIENT TERMINATED");}}}}

CLIENT:

import java.io.*;import java.net.*;class dgm_twowayclient{public static void main(String args[]) throws IOException{while(true){try{//RECEIVING MESSAGEint cport=2010;byte b[]=new byte[100];DatagramSocket datasoc=new DatagramSocket(cport);DatagramPacket datapac=new DatagramPacket(b,b.length);datasoc.receive(datapac);String s=new String(datapac.getData(),0,datapac.getLength());System.out.println("FROM SERVER");System.out.println(s);datasoc.close();if(s.equalsIgnoreCase("end"))break;

//SENDING MESSAGEint sport=2000;InputStreamReader inpstr=new InputStreamReader(System.in);BufferedReader bufred=new BufferedReader(inpstr); KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


System.out.println("TO SERVER, ENTER THE MESSAGE:");String s1=bufred.readLine();byte b1[]=s1.getBytes();InetAddress iadd=InetAddress.getByName("LocalHost");DatagramSocket datasoc1=new DatagramSocket();DatagramPacket datapac1=new DatagramPacket(b1,b1.length,iadd,2000);datasoc1.send(datapac1);datasoc1.close();}catch(IOException e){e.printStackTrace();}}}}

SCREENSHOT :

Server Window



Client Window

One-bit Sliding Window Protocols

SERVER:



import java.lang.System;import java.net.*;import java.io.*;class bitserver{public static void main(String[] args){try{BufferedInputStream bufin;ServerSocket sersoc=new ServerSocket(2000);System.out.println("WAITING FOR CONNECTION");Socket client=sersoc.accept();System.out.println("RECEIVED REQUEST FOR SENDING FRAMES");bufin=new BufferedInputStream(client.getInputStream());DataOutputStream dout=new DataOutputStream(client.getOutputStream());int p=bufin.read();System.out.println("SENDING..........");for(int i=1;i<=p;++i){System.out.println("SENDING FRAME NUMBER:"+i);dout.write(i);dout.flush();System.out.println("WAITING FOR A ACKNOWLEDGEMENT");Thread.sleep(3000);int a=in.read();System.out.println("RECEIVED ACKNOWLEDGEMENT FOR FRAME NUMBER:"+i+ "as" +a);}dout.flush();bufin.close();

dout.close();client.close();sersoc.close(); KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


System.out.println("QUITING");}catch(IOException e){System.out.println(e);}catch(InterruptedException e){}}}

CLIENT:

import java.lang.System.*;import java.net.*;import java.io.*;import java.math.*;class bitclient{public static void main(String a[]){try{InetAddress iaddr=InetAddress.getByName("LocalHost");System.out.println(addr);Socket connection=new Socket(iaddr,2000);DataOutputStream dout=new DataOutputStream(connection.getOutputStream());BufferedInputStream in=new BufferedInputStream(connection.getInputStream());BufferedInputStream inn=new BufferedInputStream(connection.getInputStream());int flag=0;

System.out.println("CONNECT");BufferedReader bufred=new BufferedReader(new InputStreamReader(System.in));System.out.println("ENTER THE NUMBER OF FRAMES TO BE REQUESTED TO SERVER:"); KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


int c =Integer.parseInt(bufred.readLine());dout.write(c);dout.flush();int i,j=0;while(j<c){i=in.read();System.out.println("RECEIVED FRAME NUMBER:"+i);System.out.println("SENDING ACKNOWLEDGEMENT FOR FRAME NUMBER:"+i);dout.write(i);dout.flush();j++;}dout.flush();in.close();dout.close();System.out.println("QUITING");}catch(Exception e){System.out.println(e);}}}

SCREENSHOT:

SERVER WINDOW:



CLIENT WINDOW:

CYCLIC REDUNDANCY CHECK



SOURCE CODE:

import java.io.*;import java.lang.*;public class crc{public static void main(String args[])throws IOException{int f[]=new int[25];int gen[]=new int[10];int rem[]=new int[10];int flen,glen,rlen,i,j,sum,p,irem,iframe,igen;String data;BufferedReader in=new BufferedReader(new InputStreamReader(System.in));System.out.print("\nENTER THE FRAME:");data=in.readLine();flen=data.length()-1;for(i=0;i<data.length();i++)f[i]=(int)(data.charAt(i))-48;System.out.print("\nENTER THE GENERATOR:");data=in.readLine();glen=data.length()-1;for(i=1;i<=glen;i++)f[flen+i]=0;flen=flen+glen;for(i=0;i<data.length();i++)gen[i]=((int)(data.charAt(i)-48));p=0;sum=0;for(i=flen;i>=0;i--){sum=sum+(f[i]*(int)Math.pow(2,p));p=p+1;}

iframe=sum; KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


p=0;sum=0;for(i=glen;i>=0;i--){sum=sum+(gen[i]*(int)Math.pow(2,p));p=p+1;}igen=sum;irem=iframe%igen;irem=igen-irem;i=0;while(iframe>0){f[i]=iframe%2;iframe=iframe/2;i++;}if(iframe==1)f[i]=iframe;System.out.println("\nTRANSMITTED STRING:");for(i=flen;i>=0;i--)System.out.println(f[i]);System.out.print("\n ENTER THE RECEIVED STRING:");data=in.readLine();flen=data.length()-1;for(i=0;i<data.length();i++)f[i]=((int)(data.charAt(i)))-48;p=0;sum=0;for(i=flen;i>=0;i--){p=p+1;

}iframe=sum;irem=iframe%igen; KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


if(irem==0)System.out.println("\n MESSAGE RECEIVED WITH NO ERROR");elseSystem.out.println("\n MESSAGE RECEIVED WITH ERROR");}}

SCREENSHOT:



IMPLEMENTATION OF REMOTE COMMAND EXECUTION

SERVER:



import java.io.*;import java.net.*;import java.lang.*;class RCEserver{public static void main(String a[])throws IOException,UnknownHostException,InterruptedException{ServerSocket sersoc=new ServerSocket(1000);Socket soc=sersoc.accept();Runtime rt =Runtime.getRuntime();Process pro=null;InputStream inpst=soc.getInputStream();DataInputStream dinpst=new DataInputStream(inpst);String s=dinpst.readLine();System.out.println(s);pro=rt.exec(s);pro.waitFor();}}

CLIENT:

import java.io.*;import java.net.*;import java.lang.*;public class RCEclient{public static void main(String a[])throws UnknownHostException,IOException{Socket soc=new Socket("LocalHost",1000);

System.out.println("\nENTER THE COMMAND:");DataInputStream dinpst=new DataInputStream(System.in);String s=dinpst.readLine();OutputStream outst=soc.getOutputStream(); KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


DataOutputStream doutst=new DataOutputStream(outst);doutst.write(s.getBytes());doutst.close();dinpst.close();soc.close();}}

SCREENSHOT:

SERVER WINDOW



CLIENT WINDOW



File Client Server

SERVER:



import java.io.*;import java.net.*;class fileserver{public static void main(String args[])throws IOException{Fserver fser=new Fserver();fser.start();}}class Fserver extends Thread{public void run(){try{System.out.println("\n SERVER WINDOW");String response="";ServerSocket sersoc=new ServerSocket(3000);String ch;boolean flag=true;while(flag){Socket soc=ss.accept();InputStream inpst=soc.getInputStream();DataInputStream dinpst=new DataInputStream(inpst);String filename=dinpst.readLine();soc.close();File f=new File(filename);if(f.isFile() && f.canRead()){

BufferedReader bufred=new BufferedReader(new FileReader(filename));String temp;while((temp=bufred.readLine())!=null) KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


{response=response+temp;response=response+"\n";soc.close();}System.out.println("\n File found displayed");}else{response="Invalied filename";}soc=sersoc.accept();PrintStream prst=new PrintStream(soc.getOutputStream());prst.print(response);soc.close();System.out.println("\n Do you want to continue:-------->y----n");DataInputStream dinpst=new DataInputStream(System.in);ch=dinpst.readLine();if((ch.equals("n"))||(ch.equals("N")))flag=false;}}catch(Exception e){System.out.println("Error from exception");}}}

CLIENT:

import java.io.*;import java.net.*; KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


class fileclient{public static void main(String srgs[])throws IOException{String ch;try{System.out.println("\n\t\tClient Window");System.out.println("Enter the filename : ");Socket soc=new Socket("LocalHost",3000);DataInputStream dinpst=new DataInputStream(System.in);String filename=dinpst.readLine();PrintStream prst=new PrintStream(soc.getOutputStream());prst.print(filename);soc.close();soc=new Socket("LocalHost",3000);DataInputStream dd1=new DataInputStream(soc.getInputStream());String result;System.out.println("\n Here is ur file content \n");while((result=dd1.readLine())!=null)System.out.println(result);soc.close();}catch(Exception e){e.printStackTrace();}}}

SCREENSHOT :

Server Window



Client Window

Simple Encryption and Decryption

SERVER:



import java.io.*;import java.net.*;public class enserver{public static void main(String args[]) throws IOException{ServerSocket sersoc;Socket soc;PrintWriter pw;BufferedReader bufred;String y="";String st="";try{sersoc=new ServerSocket(1234);soc=sersoc.accept();bufred=new BufferedReader(new InputStreamReader(System.in));System.out.println("Enter the Message : ");st=bufred.readLine();System.out.println("\n Plain Text ; " +st);int l=st.length();char c[];c=st.toCharArray();int n[]=new int[50];try{for(int i=0;i<l;i++){n[i]=(int)(c[i])+3;y+=(char)(n[i]);}}

catch(Exception e){System.out.println(e);} KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


pw=new PrintWriter(new OutputStreamWriter(soc.getOutputStream()));pw.println(y);pw.flush();System.out.println("Encrypted Message : "+y);}catch(Exception e){System.out.println(e);}}}

CLIENT:

import java.io.*;import java.net.*;public class enclient{public static void main(String args[])throws IOException{String st;Socket soc;BufferedReader bufred;String y="";try{soc=new Socket(InetAddress.getLocalHost(),1234);bufred=new BufferedReader(new InputStreamReader(soc.getInputStream()));st=bufred.readLine();System.out.println("Received Cipher text : "+st);

int l=st.length();try{char c[]=new char[10];c=st.toCharArray(); KANCHI MAMUNIVAR CENTRE FOR POST -GRADUATE STUDIES, PUDUCHERRY


int n[]=new int[50];for(int i=0;i<l;i++){n[i]=(int)(c[i])-3;y+=(char)(n[i]);}System.out.println("\n Decrypted Message : "+y);}catch(Exception e){System.out.println(e);}}catch(Exception e){System.out.println(e);}}}

SCREENSHOT :

Server Window



Client Window

IMPLEMENTATION OF CONGESTION CONTROL



SOURCE CODE:

//Leaky Bucket Algorithm for Network Congestion Control

import java.util.*;public class congestion_con { public static void main(String[] args) { Scanner my = new Scanner(System.in); int no_groups,bucket_size; System.out.print("\n ENTER THE BUCKET SIZE : \t"); bucket_size = my.nextInt(); System.out.print("\n ENTER THE NUMBER OF GROUPS : \t"); no_groups = my.nextInt(); int no_packets[] = new int[no_groups]; int in_bw[] = new int[no_groups]; int out_bw,reqd_bw=0,tot_packets=0; for(int i=0;i<no_groups;i++) { System.out.print("\n ENTER THE NUMBER OF PACKETS FOR GROUP : " + (i+1) + "\t"); no_packets[i] = my.nextInt(); System.out.print("\n ENTER THE INPUT BANDWIDTH FOR THE GROUP : " + (i+1) + "\t"); in_bw[i] = my.nextInt(); if((tot_packets+no_packets[i])<=bucket_size) { tot_packets += no_packets[i]; } else { do {

System.out.println(" BUCKET OVERFLOW "); System.out.println(" ENTER VALUE LESS THAN: " + (bucket_size-tot_packets));



no_packets[i] = my.nextInt(); }while((tot_packets+no_packets[i])>bucket_size); tot_packets += no_packets[i]; } reqd_bw += (no_packets[i]*in_bw[i]); } System.out.println("\nTHE TOTAL REQURIED BANDWITH IS: " + reqd_bw); System.out.println("ENTER THE OUTPUT BANDWIDTH: "); out_bw = my.nextInt(); int temp=reqd_bw; int rem_pkts = tot_packets; while((out_bw<=temp)&&(rem_pkts>0)) { System.out.println("Data Sent \n" + (--rem_pkts) + " packets remaining"); System.out.println("Remaining Bandwidth " + (temp -= out_bw)); if((out_bw>temp)&&(rem_pkts>0)) System.out.println(rem_pkts + " Packet(s) Discarded Due to Insufficient Bandwidth"); } }}

SCREENSHOT:




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DCN Record Vel(4)