Silverlight client Node.js server - Access denied error

I have a simple nodejs Tcp server that registers each client and broadcasts every message from the client to all other clients.

The problem was connecting with silverlight sockets. I am getting an error saying "Access Denied" when I try to connect to my public IP running nodejs Tcp server in 4530 port.

nodejs code:

net = require('net');         
var clients = [];
net.createServer(function (socket) {        
  socket.name = socket.remoteAddress + ":" + socket.remotePort 
  clients.push(socket);      
  socket.on('data', function (data) {
    broadcast(data, socket);
  });        
  socket.on('end', function () {
    clients.splice(clients.indexOf(socket), 1);

  });
  function broadcast(message, sender) {
    clients.forEach(function (client) {

      if (client === sender) return;
      client.write(message);
    });
  }     
}).listen(4530);

Silverlight code:

void Connect(string IP_Address)
{
    client_socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    SocketAsyncEventArgs socketEventArg = new SocketAsyncEventArgs()
    {
          RemoteEndPoint = new IPEndPoint(IPAddress.Parse(IP_Address), 4530)
    };
    socketEventArg.Completed += OnConncetCompleted;
    client_socket.ConnectAsync(socketEventArg);
}

void OnConncetCompleted(object sender, SocketAsyncEventArgs e)
        {
            if (e.SocketError == SocketError.Success)
            {
                this.Dispatcher.BeginInvoke(new ShowMessagedelegate(ShowMessageBox), "Connceted Successfully!");
                this.Dispatcher.BeginInvoke(new Enabledelegate(EnableControl), true);

            }
            else
            {
                this.Dispatcher.BeginInvoke(new ShowMessagedelegate(ShowMessageBox), e.SocketError.ToString());
                this.Dispatcher.BeginInvoke(new Enabledelegate(EnableControl), false);
            }

        }