Messaging Services

We have discussed the wide usage of instant messaging (IM) services such as ICQ, MSN Messenger, and others. Most of these services can work by default through a firewall, although you might have to change some configuration options. For example, in Yahoo! IM, you have to change the login preferences connection to No Network Detection. MSN Messenger can work using the WinRoute Proxy Server. You can enable proxy server by selecting Setting, Proxy for the default port 3128. The proxy server is used to access Web pages by a separate computer, so the site that is contacted is never contacted directly by the requesting machine. The proxy server makes all contact with the external site and protects the Internet computer from direct contact with the Web site. Some file transfer capabilities might be impacted when using a firewall. You have to enable some ports or set up port mapping to allow file transfers. It should be done on a case by case basis.