The Computer Corner

Sneaky Skype
By Charles Miller

An Atención reader called with questions pertaining to Skype. Skype (www.skype.com) is a free Voice over Internet Protocol (VoIP) product that permits users to make free or low-cost telephone calls over peer-to-peer (P2P) networking protocols.

Skype appears to be a great idea, but there are some dirty little secrets. They are nothing so bad as to give you a reason to stop using Skype if you are already one of the ten million users, but at least you should be informed.

If you read the fine print of the Skype EULA (End User License Agreement) you will find that you agree to let Skype use your computer and internet connection. You probably understand your using its software, but what is all this about it using your computer and your internet connection?

Skype software can act as a “Supernode.” This is a computer, your computer, that has been elevated to serve as a hub of Skype’s P2P network. Supernodes assist other users to communicate where, due to network and firewall constraints, they cannot establish direct connections.

In plain language, if your Skype software automatically elevates itself to supernode, your computer gets put to work as a switchboard handling potentially thousands of Skype calls for complete strangers.

When Skype goes into supernode mode, it opens up a great number of network connections over TCP/IP. A Skype representative confirms that some brands of routers can be overwhelmed with more than 1,500 TCP connections being opened simultaneously. Skype is reputedly able to saturate 100 megabit connections leading some universities with high-speed connections to ban its usage.

Unlike other VoIP systems, Skype is not based on any published internet standard but uses a protocol both proprietary and secret. The software has the capability of automatically upgrading itself without user permission. The company claims communications are encrypted and that its use of your computer poses no security threat, but because of the secrecy, this is not independently verifiable.

There are ways to safely use Skype while minimizing your likelihood of becoming one of its switchboards. Use MSCONFIG to turn off (not uninstall) Skype so that it does not start itself automatically every time you turn on your computer.

Only launch the Skype software when you need to use it. If you are expecting an incoming call, coordinate it through other means such as email.

As soon as your call is finished, shut down all the Skype software. Closing the Skype window is not enough because the background application continues to run. Look on your Task Bar for the green Skype icon. Right-click on this icon and choose “Quit.”

The Skype EULA used to be more upfront about explaining this, but I understand the latest versions have taken the direction of more obtuse language. Skype ought to be more forthcoming, but it cannot. The whole system of call switching and circumventing of firewalls fails without thousands of users (most unknowingly) letting their computers serve the system as supernodes.

Just remember, if you use Skype and you notice all the lights on your modem flashing with activity, well; that could either be because you are talking on the phone… or all that internet activity on your modem could be some guy in Estonia phoning his broker.

Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 044-415-101-8528 or email FAQ@SMAguru.com. 

Computers for Kids

Computadoras Pro Jovenes, founded in 2005, now has a shipping address in Dallas and Transportes San Miguel has volunteered to bring down any donated computers free of charge.

The group, whose goal is to recycle surplus computers, is up to 20 members and has seen to it that over 120 line items have been donated to area schools, many in outlying areas. They welcome donations of peripherals and software as well. Charles Miller and Edwin Sours have generously given their time and talent to restore all donated computers and install Windows in Spanish. They also install Spanish language keyboards. 

To ship a computer from the states, all the donor has to do is send it to:

CPJ/SMA coordinator

Transportes San Miguel

200 N. Marsalis

Dallas, TX 75203

Solutions, the mail forwarding service, has generously volunteered to receive the shipments and hold them until they can be picked up and renovated. 

Computadoras Pro Jovenes thanks the city of San Miguel, Transportes San Miguel and Solutions for their support.

For more information or to arrange a pick-up, please call Gordon Jett at 152-2621.