diff --git a/Implementation/src/ChatApp.class b/Implementation/src/ChatApp.class
index 952a0ce..2e60ad0 100644
Binary files a/Implementation/src/ChatApp.class and b/Implementation/src/ChatApp.class differ
diff --git a/Implementation/src/ChatApp.java b/Implementation/src/ChatApp.java
index 0330b69..4a71dd6 100644
--- a/Implementation/src/ChatApp.java
+++ b/Implementation/src/ChatApp.java
@@ -1,11 +1,9 @@
 import java.io.IOException;
-import java.net.DatagramPacket;
-import java.net.DatagramSocket;
 import java.net.InetAddress;
-import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
 
 public class ChatApp {
 	
@@ -28,20 +26,24 @@ public class ChatApp {
 		this.me = new Utilisateur(pseudo,port,ip);
 		this.actifUsers.add(me);
 	}
-
+	public void addList(Utilisateur u) {
+		this.actifUsers.add(u);
+	}
+	public void afficherListeUtilisateurs() {
+		System.out.println ("Liste des utilisateurs actifs : ");
+		for(Utilisateur elem: this.actifUsers)
+        {
+        	 System.out.println (elem.toString());
+        }	      
+	}
+	
 	public void connexion() throws IOException {
-		// Envoie en broadcast à tous les utilsateurs
-		DatagramSocket socket = new DatagramSocket();
-		socket.setBroadcast(true);
 		// @ de broadcast du réseau de l'utilisateur me 
-	    InetAddress broadcastAdress = this.me.getIp(); // A MODIFIER 
+	    InetAddress broadcastAdress = InetAddress.getLoopbackAddress(); // A MODIFIER 
 	    // Message que l'on envoie à tous les utilisateurs actifs
 		String broadcastMessage = this.me.toString() ;
-		byte[]buffer = broadcastMessage.getBytes();
-	    DatagramPacket packet = new DatagramPacket( buffer, buffer.length,  InetAddress.getLoopbackAddress(), 1234 );
-	    socket.send(packet);
-	    socket.close();
-	    System.out.println(this.me.getPseudo() + " envoie : "  + broadcastMessage);
+		Integer port = 1234 ;
+		UDPEchange.connexion(broadcastAdress,broadcastMessage, port);
 	}
 	
 	
@@ -54,29 +56,19 @@ public class ChatApp {
 		} catch (IOException e) {
 			e.printStackTrace();
 		}
-		DatagramSocket socket = null;
-		try {
-			socket = new DatagramSocket(1234);
-		} catch (SocketException e1) {
-			e1.printStackTrace();
-		} 
-		byte buffer[] = new byte[1024];
-	      while(true) 
-	      { 
-	        DatagramPacket data = new DatagramPacket(buffer,buffer.length); 
-	        try {
-				socket.receive(data);
-			} catch (IOException e) {
-				e.printStackTrace();
-			} 
-	        String received = new String(data.getData(), 0, data.getLength());
-	        System.out.println(app.me.getPseudo() + " reçoit : " + received); 
-	        app.actifUsers.add(Utilisateur.stringToUtilisateur(received));
-	        for(Utilisateur elem: app.actifUsers)
-	        {
-	        	 System.out.println (elem.toString());
-	        }	      }
-	      
+		ExecutorService exec = Executors.newFixedThreadPool(1000);
+		 exec.submit(new Runner(app));
 	}
 	
 }
+class Runner implements Runnable {
+    ChatApp app ; 
+    public Runner(ChatApp app) {
+        this.app = app ;
+    }
+    @Override
+    public void run() {
+    	UDPEchange.ecouteUDP(app);
+    }
+}
+
diff --git a/Implementation/src/Runner.class b/Implementation/src/Runner.class
new file mode 100644
index 0000000..8933e5d
Binary files /dev/null and b/Implementation/src/Runner.class differ
diff --git a/Implementation/src/RunnerUDP.class b/Implementation/src/RunnerUDP.class
new file mode 100644
index 0000000..1650904
Binary files /dev/null and b/Implementation/src/RunnerUDP.class differ
diff --git a/Implementation/src/UDPEchange.class b/Implementation/src/UDPEchange.class
new file mode 100644
index 0000000..4366d90
Binary files /dev/null and b/Implementation/src/UDPEchange.class differ
diff --git a/Implementation/src/UDPEchange.java b/Implementation/src/UDPEchange.java
new file mode 100644
index 0000000..5dfdc77
--- /dev/null
+++ b/Implementation/src/UDPEchange.java
@@ -0,0 +1,60 @@
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.net.InetAddress;
+import java.net.SocketException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class UDPEchange {
+	
+	public static void connexion( InetAddress broadcastAdress , String broadcastMessage , Integer port) throws IOException {
+		// Envoie en broadcast à tous les utilsateurs
+		DatagramSocket socket = new DatagramSocket();
+		socket.setBroadcast(true);
+		byte[]buffer = broadcastMessage.getBytes();
+	    DatagramPacket packet = new DatagramPacket( buffer, buffer.length,  InetAddress.getLoopbackAddress(), port );
+	    socket.send(packet);
+	    socket.close();
+	    System.out.println(broadcastMessage);
+	}
+	
+	public static void ecouteUDP(ChatApp app)
+	{
+		DatagramSocket socket = null;
+		ExecutorService exec = Executors.newFixedThreadPool(1000);
+		try {
+			socket = new DatagramSocket(1234);
+		} catch (SocketException e1) {
+			e1.printStackTrace();
+		} 
+		byte buffer[] = new byte[1024];
+	      while(true) 
+	      { 
+	        DatagramPacket data = new DatagramPacket(buffer,buffer.length); 
+	        try {
+				socket.receive(data);
+			} catch (IOException e) {
+				e.printStackTrace();
+			} 
+	        exec.submit(new RunnerUDP(data,app));
+	       }
+	}
+}
+class RunnerUDP implements Runnable {
+    final DatagramPacket data ;
+    ChatApp app ; 
+
+    public RunnerUDP(DatagramPacket data, ChatApp app) {
+        this.data= data;
+        this.app = app ;
+    }
+    @Override
+    public void run() {
+        System.out.println("Thread started");
+        String received = new String(data.getData(), 0, data.getLength());
+        System.out.println(received); 
+        app.addList(Utilisateur.stringToUtilisateur(received));
+        app.afficherListeUtilisateurs();
+    }
+}