Skype Dec. 23 said its service remains out for some 40 percent of its users a full day after a massive failure of its peer-to-peer computer system caused the VOIP service to deny or drop calls.
Nearly 24 hours after several computers in its P2P network went offline, Skype appears to be restoring service rapidly after suffering an unspecified "software issue."
Skype Chief Blogger Peter Parkes said around 7 a.m. EST that while there are roughly 5 million people online, it was only around 30 percent of what the company would expect at that particular time.
By 9 a.m. EST, Parkes said in an update, that number had doubled to more than 10 million, or 60 percent of total users Skype typically sees online then. That means Skype remains unavailable for about 40 percent of users.
"Unfortunately, it's not possible for us to predict on an individual level when you'll be able to sign in again, and we thank you for your patience in the meantime," Parkes added.
Parkes said that while Skype Manager, group video calling and other Web-based tools remain offline and instant messaging and online status are slow, the company's Skype Connect enterprise product is working normally.
Updated 1:50 EST: Skype CEO Tony Bates said 16.5 million users, or roughly 80 percent of normally expected users, are now back on Skype. IM, audio and video are restored, but it will take longer to bring offline IM and group video calling back online.
Skype, used by millions of users to make free or low-cost long-distance calls from their PCs and phones, began failing for users around 11 a.m. EST Dec. 22.
Parkes said that after the company engineers noticed that the number of users online fell, it found that its "supernodes" had failed.
Supernodes are end users' computer linked by Skype's P2P software, acting like virtual phone directories. Skype employs millions of connections between supernodes and phones.
When a user clicks to place a call on Skype and the app can't locate a user's computer or phone, it will attempt to ping a supernode to connect the call. When the supernodes conked out, millions of people were unable to make calls.
Dan York, director of conversations at Voxeo, provided a detailed explanation of supernodes on his DisruptiveTechnology blog here for those interested in Skype's network architecture.
"We're working hard to restore full functionality to the Skype software, and hope to have more information to share soon," Parkes added.
Users may follow Skype updates here on the service's Twitter account.