Why Skype could mean a slow Internet connection

It’s already known that Skype eats away at your bandwidth even when you aren’t using it. Now it appears it can be a bigger threat to PC performance than previously realized.

The reason Skype uses the bandwidth is that the system operates on a peer-to-peer basis, similar to many major filesharing services. That means that even when you aren’t making a call, your computer can still be sending data back and forth. This isn’t necessarily call data, but can simply be down to Skype checking which other contacts are online.

Early last year, Blorge’s Gareth Powell had his internet connection speed capped by his provider, apparently for exceeding data transfer limits. He eventually fingered Skype as the culprit, noting that though Skype says “normal” background use should only go as high as 0.5 kilobytes per second, that’s still the equivalent of 1.3GB a month for a machine running 24/7.

Now the developers of a forthcoming application, PerfProtector, which detects unusual behavior on the processes running in Windows say their beta testing shows Skype is consistently by far the biggest offender when it comes to bandwidth hogging.

They suspected the problem was that that Skype effectively “targets” computers which are online for long periods, or even permanently, and have fast connections. These machines are then used as supernodes, the hubs of the network of Skype users.

To test this theory, they left a computer switched on with Skype running for nine days and monitored how many separate connections Skype made:

(Picture courtesy of PerfProtect)

The problem, then, is that Skype appears to have no limits on how many connections it will make on a single machine: if it finds something useful, it will take full advantage, regardless of what effect that has on the machine’s internet performance.

The makers of PerfProtect recommend forcing Skype to not use your machine as a supernode: it involves editing the Windows registry, so proceed with caution. As they note, if everyone did this, Skype would collapse, but given their findings this appears to be a case where it may be better to be selfish.

• 

• Skype steals bandwidth — even when you are not using it
• Skype video chat coming to Facebook?
• Microsoft update kills Internet connection for ZoneAlarm firewall users
• Skype releases its Skype 1.4 Linux version
• Call transfers enabled in Skype 4.2 beta