@rajeev86: Man, that is so typical about BSNL. Tell you what, I will speak to BSNL Customer Service with a friend's DataOne connection tomorrow and let you know. There has to be a way to get through to them. I will install AoE2 on his computer and try playing online and we'll see what happens.
@tuxian: Adding to what digen has already explained. Windows, in its normal working mode, does not monitor or control outbound network traffic. Windows Firewall or even TCP Filtering in the TCP/IP Advanced Properties allows only control of incoming traffic, not outbound. So, let us say you dont have a firewall to control outbound traffic and you have an unrestricted open Internet connection, then when you install a program that requests a specific port, Windows WILL allow communication on that port. If you have not restricted inbound traffic directed to that port or if you have not blocked inbound access to ANY other port that the program listens on, then the program WILL establish two-way communication with the server. And literally tons of programs request open ports - be it Windows System applications, rundll32, spooler subsystem, Windows Explorer, Internet Explorer, Outlook Express, Microsoft Outlook, FTP, P2P software, webservers, database servers, multiplayer gaming and a host of other programs request use of their own ports. In addition, you can write your own code to open and request communications on a specific port, from anyone of the 65,536 ports available. So, in say, a Java program I can write a code such as
int port=9999;
ServerSocket s=new ServerSocket(port)
and have my Java program communicate on port 9999. I can setup a client to connect to this port at the code level with:
int port=9999;
InetAddress address=InetAddress.getByName(null); //getting the address of the server, localhost
Socket socket=new Socket(address, port);
If the client or the server computer has a firewall blocking port 9999 actively, then the programs wont work. You can check which ports are established or waiting or listening for connections by going to the command prompt and entering:
netstat -abo
which will give you a list of connections, their state and which executable/program was involved in using that port. And you will be able to see the huge number of ports that a typical online Windows box uses. Run the command on your computer to check it out. There are tons of programs communicating on a heckuva lot of ports.