Founded in August of last year by the brain trust behind the (in)famous Kazaa peer-to-peer file-sharing program, Skype is touted as being the first true peer-to-peer telephony program. Essentially, the technology that made Kazaa so successful (and difficult to sue) is being used to power voice communication over the Internet.

What makes this method distinct is that it lacks a central 'server' containing user data and connection information. Each system running Skype becomes a node in a vast network of Skype users, who share the necessary database information required to keep each user informed of who is online at any given moment. Calls may also be routed through other Skype 'nodes' when direct communication is unfeasible.

The idea of Skype is to have a self-maintaining network of users, who can communicate with each other by voice just as they would communicate using an instant messenger program like ICQ. Distance and location are irrelevant as long as you are connected to the Internet. There are no costs or time limitations attached to calling. You have 'buddy' lists just like ICQ or MSN, and can search the Skype database for people to contact.

The makers of Skype also tout its ability to pass through conventional firewall devices and applications mostly unscathed, a feat which has given pause to previous VoIP software applications. While the Skype site is not too forthcoming about how this is accomplished, it seems to use much the same method as recent Kazaa implementations. In other words, it uses a dynamic assortment of TCP ports to connect and send data, falling back on port 80 (the standard HTTP port used to connect to web servers) if it is blocked elsewhere. The software uses a single UDP port (or port 80 again) to listen for incoming data.

While Kazaa's ability to negotiate firewall security has made it a scourge to company sysadmins everywhere, Skype promises to use the technology for a much more beneficial purpose: user friendliness.

How many people have firewalls built into their home Internet sharing devices and have no idea how to configure them? A lot. And once Service pack 2 for Windows XP is released, factor every single Windows XP user into the equation, since the XP firewall will be enabled by default by the service pack.

Several previous VoIP implementations have been handicapped by their dependence on a static set of ports which are often blocked by default with the average firewall. While these ports can be opened, most users may not have the desire to get this technical.

As we said, Skype is still in beta testing. The manufacturers have stated that while they intend to keep the core service free after it clears beta testing (though no doubt ad subsidized), they will offer premium memberships with perks like conference calling (currently free in the beta) and voice boxes that would be desired by a more business oriented user base.

There is a general move towards VoIP solutions in the market, with some suggestions that Microsoft will integrate VoIP into its next Windows version, or release a product or add-on even sooner.