Multicast server/client over wan

Question

Ok, first of I am kinda new in programming network stuff.
Then I am gonna try to be clear in the things that I am trying to accomplish.
The environement.
I have a machine A that has 2 interfaces :
eth0 Link encap:Ethernet HWaddr 00:0F:20:96:CE:96
inet addr:192.168.1.49 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2328871 errors:0 dropped:0 overruns:0 frame:0
TX packets:355492 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:178361234 (170.0 Mb) TX bytes:34186479 (32.6 Mb)
Interrupt:11
eth2 Link encap:Ethernet HWaddr 00:04:23:45:74:EC
inet addr:192.168.2.2 Bcast:192.168.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:813915 errors:0 dropped:0 overruns:0 frame:0
TX packets:7538202 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:53318289 (50.8 Mb) TX bytes:1092719670 (1042.0 Mb)
Interrupt:15 Base address:0x3000 Memory:f7ee0000-f7f00000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:56496 errors:0 dropped:0 overruns:0 frame:0
TX packets:56496 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:7952617 (7.5 Mb) TX bytes:7952617 (7.5 Mb)
This machine is connected thru a router
The routers connects to a WAN with MULTICAST enabled
then another router to which the second machine is connected
MACHINE B
eth0 Link encap:Ethernet HWaddr 00:0F:20:96:0F:94
inet addr:192.168.1.58 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:2322957 errors:0 dropped:0 overruns:0 frame:0
TX packets:363116 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:177550404 (169.3 Mb) TX bytes:33507499 (31.9 Mb)
Interrupt:30
eth2 Link encap:Ethernet HWaddr 00:04:23:45:78:90
inet addr:192.168.3.2 Bcast:192.168.3.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:160838 errors:0 dropped:0 overruns:0 frame:0
TX packets:6781 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:11450177 (10.9 Mb) TX bytes:746369 (728.8 Kb)
Interrupt:28 Base address:0x3000 Memory:f7ee0000-f7f00000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:158 errors:0 dropped:0 overruns:0 frame:0
TX packets:158 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:23916 (23.3 Kb) TX bytes:23916 (23.3 Kb)
The two machine are on different networks.
My goal is to have Machine A send multicast data thru eth2 to be sent in the wan and to be received by Machine B on eth2 too.
Obviously the two machine are on separated networks.
I have tried everything I could but I cannot get machine B to pickup the messages sent by A. It worked fine when on the same LAN but not over WAN.
The multicast address that I use it 239.55.55.80 and the port 4445.
I think I have a problem to link the interface to my app ( I used setInterface and setNetworkinterface but nithing.) Also I cannot firgure out if the things that I am doing wrong are on the server or the client.
Here is the code for the sever and client.
SERVER
package com.cme.multicastijector.server;
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2004</p>
* <p>Company: </p>
* @author not attributable
* @version 1.0
import java.net.*;
import java.util.*;
public class MulticastOutputSocket {
private int m_multicastPort = 0;
private MulticastSocket m_multicastSocket = null;
private InetAddress m_interfaceAddress = null;
private InetAddress m_multicastAddress = null;
private InetSocketAddress m_inetSocketAddress = null;
private int m_bufferSize = 0;
private byte[] m_outputBuffer = null;
private DatagramPacket m_packet = null;
public MulticastOutputSocket(int portNumber,String interfaceAddress,String multicastAddress,int bufferSize) throws Exception{
System.out.println("\nStarting multicast output socket");
m_multicastPort = portNumber;
m_interfaceAddress = InetAddress.getByName(interfaceAddress);
m_multicastAddress = InetAddress.getByName(multicastAddress);
m_bufferSize = bufferSize;
m_inetSocketAddress = new InetSocketAddress(m_multicastAddress,m_multicastPort);
m_multicastSocket = new MulticastSocket (m_multicastPort);
// m_multicastSocket.joinGroup(m_inetSocketAddress,NetworkInterface.getByInetAddress(m_interfaceAddress));
m_multicastSocket.setNetworkInterface(NetworkInterface.getByInetAddress(m_interfaceAddress));
// m_multicastSocket.setLoopbackMode(false);
// m_multicastSocket.setTimeToLive(32);
Enumeration e = NetworkInterface.getNetworkInterfaces();
while (e.hasMoreElements()){
System.out.println(e.nextElement().toString());
System.out.println("Interface Address = " + m_interfaceAddress);
System.out.println("Multicast Address = " + m_multicastAddress);
System.out.println("Port = " + m_multicastPort);
System.out.println("BufferSize = " + m_bufferSize);
System.out.println("MulticastSockect initialized.\n");
public void sendData(String data) throws Exception{
m_outputBuffer = new byte[m_bufferSize];
m_outputBuffer = data.getBytes();
//m_packet = new DatagramPacket(m_outputBuffer, m_outputBuffer.length);
m_packet = new DatagramPacket(m_outputBuffer, m_outputBuffer.length, m_inetSocketAddress);
m_multicastSocket.send(m_packet);
public void closeSocket() throws Exception {
//m_multicastSocket.leaveGroup(m_multicastAddress);
//m_multicastSocket.leaveGroup(m_inetSocketAddress,NetworkInterface.getByInetAddress(m_interfaceAddress));
m_multicastSocket.close();
CLIENT
package com.cme.multicastijector.client;
* <p>Title: </p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2004</p>
* <p>Company: </p>
* @author not attributable
* @version 1.0
import java.io.*;
import java.net.*;
import java.util.*;
public class MulticastClient {
private Properties m_prop = null;
private MulticastSocket m_multicastSocket = null;
private InetAddress m_interfaceAddress = null;
private InetAddress m_multicastAddress = null;
private InetSocketAddress m_inetSocketAddress = null;
private int m_multicastPort = 0;
private int m_bufferSize = 0;
private int m_previousSeq = 0;
private boolean m_isFirst = true;
private int m_actualseq = 0;
private int m_msgLost = 0;
private int m_messagesReceived = 0;
private Object m_seqLock = new Object();
private Object m_msgLock = new Object();
public MulticastClient(Properties properties) throws Exception{
m_prop = properties;
init();
new TpsCalculator();
receiveData();
private void init() throws Exception{
m_multicastPort = Integer.parseInt(m_prop.getProperty("MULTICAST_PORT"));
m_multicastAddress = InetAddress.getByName(m_prop.getProperty("MULTICAST_ADDRESS"));
m_interfaceAddress = InetAddress.getByName(m_prop.getProperty("INTERFACE_ADDRESS"));
m_bufferSize = Integer.parseInt(m_prop.getProperty("BUFFER_SIZE"));
m_inetSocketAddress = new InetSocketAddress(m_multicastAddress,m_multicastPort);
m_multicastSocket = new MulticastSocket (m_multicastPort);
// System.out.println("DEFAULT INTERFACE : " + m_multicastSocket.getInterface() );
// System.out.println("DEFAULT INTERFACE : " + m_multicastSocket.getNetworkInterface() );
// m_multicastSocket.setInterface(m_interfaceAddress);
// m_multicastSocket.setNetworkInterface(NetworkInterface.getByInetAddress(m_interfaceAddress));
// System.out.println("DEFAULT INTERFACE : " + m_multicastSocket.getInterface() );
// System.out.println("DEFAULT INTERFACE : " + m_multicastSocket.getNetworkInterface() );
m_multicastSocket.joinGroup(m_inetSocketAddress,NetworkInterface.getByInetAddress(m_interfaceAddress));
// m_multicastSocket.joinGroup(m_multicastAddress);
System.out.println("Interface Address = " + m_interfaceAddress);
System.out.println("Multicast Address = " + m_multicastAddress);
System.out.println("Port = " + m_multicastPort);
System.out.println("BufferSize = " + m_bufferSize);
private void receiveData() throws Exception{
try {
String received = null;
byte[] inputBuffer = null;
DatagramPacket packet = null;
while(true){
inputBuffer = new byte[m_bufferSize];
packet = new DatagramPacket(inputBuffer, inputBuffer.length, m_inetSocketAddress);
m_multicastSocket.receive(packet);
received = new String(packet.getData());
m_messagesReceived++;
synchronized(m_seqLock){
m_actualseq = getSequence(received);
checkSequence(m_actualseq);
catch (Exception ex) {
ex.printStackTrace();
m_multicastSocket.close();
private int getSequence(String data){
return Integer.parseInt(data.substring(0,15));
private void checkSequence(int actual){
if(m_isFirst){
m_isFirst = false;
m_previousSeq = actual;
else{
if ( (m_previousSeq + 1) != actual) {
synchronized(m_msgLock){
m_msgLost += (actual - m_previousSeq)-1;
m_previousSeq = actual;
private class TpsCalculator extends TimerTask{
private Timer aTimer;
private int previousSeq = 0;
private int tpsSeq = 0;
private int tpsRec = 0;
private boolean first = true;
private int msglost = 0;
private int previousMsgRec = 0;
private int actualMsgRec = 0;
public TpsCalculator(){
aTimer = new Timer();
aTimer.scheduleAtFixedRate(this,new Date(),1000);
System.out.println("#####################################################");
System.out.println("time,tps from sequences, actual tps,total msg received,msglost");
public void run(){
actualMsgRec = m_messagesReceived;
tpsRec = actualMsgRec - previousMsgRec;
previousMsgRec = actualMsgRec;
if(first){
synchronized(m_seqLock){
previousSeq = m_actualseq;
first = false;
else{
synchronized(m_msgLock){
msglost = m_msgLost;
m_msgLost = 0;
synchronized(m_seqLock){
tpsSeq = m_actualseq - previousSeq;
previousSeq = m_actualseq;
System.out.println(new Date()+","+tpsSeq + "," + tpsRec + "," + m_messagesReceived + "," + msglost);
Thanks for your help.
This is really important for the project I am working on.
Thanks again

Answer 1

never Mind I found the issue
The default value for TTL is 1.
I was going thru multiple routers so I incremented the value and it worked
thanks