O'Reilly Network: What Is Skype: "What Is Skype
by James E. Gaskin
Skype lets you make free calls over the internet to anyone else who also has the service. It's free and easy to download and use, and it works with most computers. Skype offers free global telephony and unlimited voice calls with its next-generation peer-to-peer software.
This article discusses the following:
1. The Viral Phone Service
2. How Skype Works
3. Skype Extras and Presence
4. Skype Limitations
It's a bird, it's a plane--it's an advanced communications peer-to-peer network disguised as a phone service? Skype calls itself 'free Internet telephony that just works,' but it's much more than that, even if the company plays coy about all that Skype can do.
Slipping onto the scene back in August 2003, Skype came from the two principals behind the KaZaA file-sharing network. Founders Zennstrom and Friis call Skype a third-generation peer- to-peer network, quietly putting KaZaA in their past. (They sold the service before most of the bad press started.) Their background in peer-to-peer networking makes Skype a different type of telephone service in a number of ways.
Skype works on a decentralized model, meaning there are no big phone switches and controlling computers in regional data centers, such as those that power Vonage and other broadband phone service providers. The only centralized Skype services at the beginning were the login servers, which also show which other Skype users are online. The switches that followed control SkypeOut calls to traditional telephone networks around the world. Adding Skype Voicemail and SkypeIn (still in beta in early August) requires more centralized resources, and Skype data centers are growing as you read this. But Skype's low infrastructure cost per number of subscribers creates jealousy among every other broadband phone service provider.
The Viral Phone Service
Primarily, Skype offers free software that lets you talk by way of the internet to another Skype user, anywhere in the world, for free. Your computer (or PocketPC) works as your phone.
Free Skype client software for Windows, Macintosh, Linux (Red Hat/Fedora Core, SuSE, Mandrake/Mandriva, and multiple Debian flavors such as Xandros, MEPIS, and Ubuntu), and PocketPC may be downloaded free from the Skype.com site. People download Skype client software by the millions every month. At the beginning of 2005, the download counter was around 75 million (the download number includes active customers downloading updates). At the beginning of August 2005, the counter showed more than 144 million downloads.
Skype's marketing expenses for advertising and other, normal company rollout hoopla: zero. More than 25 million registered users, 3 million-plus of whom are often online concurrently, were persuaded to join Skype by word of mouth.
Other internet telephony services, such as Vonage, Verizon, Packet8, ATT CallVantage, and others, spend hundreds of dollars of marketing and advertising money to find each new customer. Skype spends nothing except for the server support to keep its download files available.
Forget the technology, and appreciate that Skype became so cool and desirable that 25 times more people have registered for Skype than all other broadband phone services combined. Skype fans, every bit as rabid as early Macintosh fans, spread the word 25 million times that Skype was a hip and free method of talking to friends anywhere in the world."
Skype setup and configuration rates among the easiest of any application you're likely to use. This is by design. Founders said they planned for Skype to be the most user-friendly application available today, and they may have hit their target.
Be prepared for two surprises. First, although tied to a computer, Skype uses standard telephone sounds. Second, the audio quality will amaze you.
Those hurrahs aside, there are some caveats. Your computer must be turned on to use Skype, and people you call must have Skype running on their system in order to receive your call. Skype spreads by one person encouraging another to download Skype and call them, and that call usually comes within five minutes. Technically, a dial-up connection will suffice, but realistically you need broadband to really enjoy Skype.
Skype Extras and Presence
So far, we've looked at how Skype can replace a standard phone or cell phone. No big deal, aside from the drastically improved call quality. But dig a little deeper into what else Skype offers now and plans to roll out soon, and you realize Skype is the most advanced voice communications tool available today.
What you don't realize, because Skype doesn't make a big deal out of it, is that every Skype connection uses 256-bit encryption. The call quality astounds people, so no one guesses the encryption is automatic and engaged on every connection. You must move to restricted military telecom hardware to get a higher level of encryption than what Skype provides, free, on every call. Look for some serious hand-wringing among law enforcement and the Department of Homeland Security when they finally realize how prevalent Skype is worldwide.
Skype's standard features are:
* Talking free to other Skype users
* Conference call with up to five total Skype users
* File transfers
* Chat (instant messaging)