eBay's explanation for last week's failure of its Skype communication service has left many users still wondering what caused the worst outage in Skype's five-year history.
Millions of Skype users were knocked offline last week when a programming bug made it impossible for most users to connect during a 36-hour period, starting last Thursday.
On Monday, Skype said the disruption was kicked off when a large number of Skype users restarted their computers after installing Microsoft's monthly security software updates, which were pushed out to Windows users starting on Tuesday.
Skype's peer-to-peer network was "not properly tuned to cope with the load and core size changes that occurred," after a large number of users restarted their machines and the Skype network was flooded with new log-in requests, said Skype spokeswoman Jennifer Caukin, in an e-mail. "This disruption was unprecedented in terms of its impact and scope."
Skype has "introduced a number of improvements to its software to ensure that our users will not be similarly affected in the unlikely possibility of this combination of events recurring," Caukin added, without saying what exactly had changed.
Microsoft releases its security patches on the second Tuesday of each month, so this type of widespread restarting is nothing new. Skype hasn't said what in particular about August's updates led to the network crash, and its vagueness on the issue is causing some Skype users to cry foul.
"What was different this time from previous [Microsoft] updates?" asked Jim Courtney, a business consultant based in Mississauga, Ontario, and a contributor to the Skype Journal website.
Skype business partners want to know what went wrong and, more importantly, what steps the company has taken to ensure the problem won't happen again. "They've got to explain what they've done to increase the peer-to-peer network resources...and they haven't done that," Courtney said.
Andrew Hansen, whose company designs software to work on the Skype network, said he's scratching his head over Skype's explanation of the problem. "What was released by their PR agency doesn't make any sense at all," he said.
"If they want to present themselves as an open communications company, I think a public audit wouldn't be too much to suggest," said Hansen, CEO of Virtual Communication in Collingwood, Ontario. "The worst thing you can do is try to sweep something under the rug with a press release."
Microsoft said it has been in discussions with the Skype team and determined that its August updates did not cause the outage. Microsoft didn't change the way it delivered its August updates, said a spokeswoman with the company's public relations agency, via e-mail. "Nothing [was] different on our side," she said.
The security community took an interest in the blackout after Skype attack code was posted to a Russian hacking forum late last week. Skype says it was not attacked, and security experts contacted by IDG News Service said the purported attack code probably could not have caused last week's outage.
Still, Skype still has a lot of explaining to do, said John Bambenek, a security researcher at the University of Illinois at Urbana-Champaign and volunteer at the Internet Storm Center.
Bambenek wonders why this kind of outage didn't occur earlier, what exactly went wrong, and what exactly Skype has done to prevent it from happening again in the future.
"The only thing I'm pretty sure of is that Skype is hiding information," he said in an e-mail interview.