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If you're having connection problems, here's an elaborate overview of most common ways to connect 2 (or more) computers via the internet. If your computer and the computer you want to connect with are directly connected to the internet, only a firewall or other software on the computer itself can prevent a connection from being made. [ Local computer ] | | Local address ----, | | Internet | Remote address ----' | | [ Remote computer ] An address above consists of an IP address, like "213.46.58.164", and one or more ports, like 80, 1080 and 1234. Combined "213.46.58.164:1234". In many cases domain names and computer names are also supported, for example "Elize:21" and "mydomain.com:80". +----------------+ | Computer | +----------------+ / 213.46.58.164 \ IP Address +------+------+------+ | 80 | 1080 | 1234 | Ports +------+------+------+ || || || || || || Connections Any computer can connect using virtually any IP address, from any port to any port, and to virtually any IP address. Most commonly only 1, or a few ports, are used, and are identical on each side (local and remote). If you have software on your computer that blocks traffic through ports you want to use, you have to dive into that software and open those ports you want to use. Often your computer is not directly connected to the internet. [ Your computer ] | | Your LAN address ----------, | | Router / Hub | Your internet server address ----' | | [ Your internet server ] (gateway) | | Your internet address --------, | : Internet . A router / hub is used to connect multiple computers to each other. Computer Computer Computer | \ | / \ / .------. Computer --- ( Router ) --- Internet server `------' / \ / | \ | Computer Computer Computer Each computer uses a Local Area Network (LAN) address to connect. The internet server has 2 network interfaces; one to connect to the LAN, basically your home network, and one to connect to the internet, which has the 'internet address', which is the shared by all computers in this LAN. The Router / Hub can also be combined with the internet server, to become an 'internet router' where you can simply plug in multiple computers to gain access to the internet (and/or each other). [ Your computer ] | | Your LAN address ----------, | | <-- Only a cable here :) | Your internet router address ----' | | [ Your internet router ] (gateway) | | Your internet address --------, | : Internet . A common IP address for an internet server is "192.168.0.1", And a common IP address for an internet router is "10.0.1.1". Because these addresses gain access to the internet, these are also known as gateways, opening the gate to clear the way. The gateway address can be virtually any IP address. To find out your internet address in an easy way, go to an online IP address check webpage such as http://www.ipchicken.com/ If you are using a program that uses the TCP/IP protocol to connect, one computer will be the master (server) which hosts, and one will be the slave (client) which joins the host. If you want to connect to a computer that's behind a gateway, e.g. a computer that's actually on a LAN, located behind a internet router or server, the internet router or server will have to know who of the computers on the LAN you want to connect to. Most commonly this is done by 'port forwarding', which means you configure the internet router / server to link an external port with an IP address (or computer name) on the LAN. Most internet routers can be configured by using a web browser, and most internet servers use 'port forwarding'-capable internet server software. +-----------------+ | Your computer | +-----------------+ +--------+--------+ | 192.168. 0. 2 | | 1002 | 1003 | +-----------------+ +--------+--------+ || || || || [ LAN ] || || || || +-----------------+ +--------+--------+ | 192.168. 0. 1 | | 1002 | 1003 | +-----------------+ +--------+--------+ | Internet router | +-----------------+ +--------+--------+ | 213. 46. 58.164 | | 1002 | 1003 | +-----------------+ +--------+--------+ || || || || [ Internet ] || || || || +-----------------+ +--------+--------+ | 66.249. 72.161 | | 1002 | 1003 | +-----------------+ +--------+--------+ | Remote computer | +-----------------+ Here ports 1002 and 1003 are linked to "192.168.0.2" in the internet router. Some routers also support forwarding port ranges, e.g. multiple ports at a time, for example linking all ports from 1002 to 1020 to "192.168.0.1". And some routers can change the internal/external port offset, e.g. the starting port, for example forwarding incoming port 1002 to "192.168.0.1:1234". If you are behind a gateway and unable to open ports yourself, for example even if you ask an administrator :) you can try some commonly used ports such as: 80 (HTTP), 1080 (proxy) and 21 (FTP). There are actually 2 port types, TCP and UDP, of which TCP is most common. TCP ports are commonly used by the TCP/IP protocol, and UDP ports, which do not require a connection to be established, are commonly used by the UDP protocol. Examples of TCP port applications: websites, file transfers, chat programs. TCP overview: reliable/ordered packets, requires connection, high latency. Example of UDP port applications: fast-paced real-time online games. UDP overview: unreliable/unordered packets (faster), connectionless, low latency. Most port forwarding configuration software / hardware provides a clean overview. Internet Router: ----------------------------------------------------------------------------- Internet LAN ------------------------------ -------------------------- IP Ports IP Ports Notes --------------- --------- --- --------------- --------- ----------------- any 1002 any 192.168. 0. 2 same Single port any 1003-1009 any 192.168. 0. 2 same Port range any 1010-1020 any 192.168. 0. 2 1234-1244 New port offset any 21 TCP 192.168. 0. 2 same My FTP server any 7777-7778 UDP 192.168. 0. 2 same Unreal Tournament If your internet router does not have a manual, make sure it's not on the CD, or try figuring out the name of the brand and model, usually on the device itself (or on the bottom sticker), so you can look it up on Google ( http://www.google.com/ ), and download a manual, or read it online. Good luck! :) If you still can't find the answer, you can email me at < TheChange@yahoo.com >. Teasy.