Ym is based on HTTP, which means you can use it as long as you have access to internet. Icq is based on Socks( socks4 or socks5), the port number is 1080 something. :)
Check your LAN to ensure the port is not restricted, before you are going to run it. If it is unfortunately restricted, try to get a free proxy (socks4 or socks5), have it setted with your network configuration, it works.