diff --git a/src/clientP2P/ClientP2P.java b/src/clientP2P/ClientP2P.java
index 2d56fd8..34a9519 100644
--- a/src/clientP2P/ClientP2P.java
+++ b/src/clientP2P/ClientP2P.java
@@ -71,57 +71,63 @@ public class ClientP2P {
 	 * @param args	server listenning port
 	 */
 	public static void main(String [] args) {
-		ClientP2P c;
-		try {
-			c = new ClientP2P(args[1]);
-		} catch (IndexOutOfBoundsException e){
-			c = new ClientP2P("" + defaultPort);
+
+		if (args[1].equals("help") || args[1].equals("-h") || args[1].equals("h")){
+			System.out.println("usage : java -ea clientP2P.ClientP2P -- <PORT> ");
 		}
+		else{
+			ClientP2P c;
+			try {
+				c = new ClientP2P(args[1]);
+			} catch (IndexOutOfBoundsException e){
+				c = new ClientP2P("" + defaultPort);
+			}
 
-		// Server threads
-		ServerManagementUDP smudp = new ServerManagementUDP(c.directories.getDataHomeDirectory() + subdir, c.port, c.loggerServer);
-		ServerManagementTCP smtcp = new ServerManagementTCP(c.directories.getDataHomeDirectory() + subdir, c.port, c.loggerServer);
-		Thread tudp = new Thread(smudp);
-		tudp.setName("server UDP P2P-JAVA-PROJECT (port: " + c.port + ")");
-		tudp.start();
-		Thread ttcp = new Thread(smtcp);
-		ttcp.setName("server TCP P2P-JAVA-PROJECT (port: " + c.port + ")");
-		ttcp.start();
+			// Server threads
+			ServerManagementUDP smudp = new ServerManagementUDP(c.directories.getDataHomeDirectory() + subdir, c.port, c.loggerServer);
+			ServerManagementTCP smtcp = new ServerManagementTCP(c.directories.getDataHomeDirectory() + subdir, c.port, c.loggerServer);
+			Thread tudp = new Thread(smudp);
+			tudp.setName("server UDP P2P-JAVA-PROJECT (port: " + c.port + ")");
+			tudp.start();
+			Thread ttcp = new Thread(smtcp);
+			ttcp.setName("server TCP P2P-JAVA-PROJECT (port: " + c.port + ")");
+			ttcp.start();
 
-		// Wait a bit before printing client interface
-		// This is not required, but allow to have a cleaner interface
-		try {
-			Thread.sleep(100);
-		} catch(InterruptedException e) {
-			Thread.currentThread().interrupt();
-		}
+			// Wait a bit before printing client interface
+			// This is not required, but allow to have a cleaner interface
+			try {
+				Thread.sleep(100);
+			} catch(InterruptedException e) {
+				Thread.currentThread().interrupt();
+			}
 
-		// initialize Host lists
-		c.hostList = HostList.getServList();
-		System.out.println("Client : Which transport protocol do you want to use? [TCP/udp]");
-		Scanner sc = new Scanner(System.in);
-		String transportchoosen = sc.nextLine();
-		Thread t;
-		switch(transportchoosen){
-			case "UDP":
-			case "udp":
-			case "upd": // alias typo
-			case "2" :
-				System.out.println("Starting with UDP");
-				ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.hostList, c.directories.getDataHomeDirectory() + c.parts + "/", c.loggerClient);
-				t = new Thread(cmudp);
-				break;
-			case "TCP":
-			case "tcp":
-			case "1":
-			default:
-				System.out.println("Starting with TCP");
-				ClientManagementTCP cmtcp = new ClientManagementTCP(c.directories.getDataHomeDirectory(), c.hostList, c.directories.getDataHomeDirectory() + c.parts + "/", c.loggerClient);
-				t = new Thread(cmtcp);
-				break;
-		  }
+			// initialize Host lists
+			c.hostList = HostList.getServList();
+			System.out.println("Client : Which transport protocol do you want to use? [TCP/udp]");
+			Scanner sc = new Scanner(System.in);
+			String transportchoosen = sc.nextLine();
+			Thread t;
+			switch(transportchoosen){
+				case "UDP":
+				case "udp":
+				case "upd": // alias typo
+				case "2" :
+					System.out.println("Starting with UDP");
+					ClientManagementUDP cmudp = new ClientManagementUDP(c.directories.getDataHomeDirectory(), c.hostList, c.directories.getDataHomeDirectory() + c.parts + "/", c.loggerClient);
+					t = new Thread(cmudp);
+					break;
+				case "TCP":
+				case "tcp":
+				case "1":
+				default:
+					System.out.println("Starting with TCP");
+					ClientManagementTCP cmtcp = new ClientManagementTCP(c.directories.getDataHomeDirectory(), c.hostList, c.directories.getDataHomeDirectory() + c.parts + "/", c.loggerClient);
+					t = new Thread(cmtcp);
+					break;
+				}
 
-		t.setName("client P2P-JAVA-PROJECT");
-		t.start();
+			t.setName("client P2P-JAVA-PROJECT");
+			t.start();
+		}
 	}
 }
diff --git a/src/serverP2P/ServerP2P.java b/src/serverP2P/ServerP2P.java
index 313d263..be8bfec 100644
--- a/src/serverP2P/ServerP2P.java
+++ b/src/serverP2P/ServerP2P.java
@@ -35,15 +35,21 @@ public class ServerP2P {
 	 * @param args	parameters
 	 */
 		public static void main(String [] args) {
-		ServerP2P s = new ServerP2P(args[1]);
-		ServerManagementUDP smudp = new ServerManagementUDP(s.directories.getDataHomeDirectory() + subdir, s.port, s.logger);
-		ServerManagementTCP smtcp = new ServerManagementTCP(s.directories.getDataHomeDirectory() + subdir, s.port, s.logger);
-		Thread tudp = new Thread(smudp);
-		tudp.setName("server UDP P2P-JAVA-PROJECT");
-		tudp.start();
-		Thread ttcp = new Thread(smtcp);
-		ttcp.setName("server TCP P2P-JAVA-PROJECT");
-		ttcp.start();
+
+			if (args[1].equals("help") || args[1].equals("-h") || args[1].equals("h")){
+				System.out.println("usage : java -ea serveurP2P.ServeurP2P -- <serveurPORT> <trackerHOSTNAME> <trackerPORT>");
+			}
+			else{
+				ServerP2P s = new ServerP2P(args[1]);
+				ServerManagementUDP smudp = new ServerManagementUDP(s.directories.getDataHomeDirectory() + subdir, s.port, s.logger);
+				ServerManagementTCP smtcp = new ServerManagementTCP(s.directories.getDataHomeDirectory() + subdir, s.port, s.logger);
+				Thread tudp = new Thread(smudp);
+				tudp.setName("server UDP P2P-JAVA-PROJECT");
+				tudp.start();
+				Thread ttcp = new Thread(smtcp);
+				ttcp.setName("server TCP P2P-JAVA-PROJECT");
+				ttcp.start();
+			}
 	}
 
 }