Skype's IP telephony service is now up and running, after two days of technical problems.

The company announced late Friday that all users could log on to the service, marking the end of an outage that affected millions and lasted more than 48 hours.

At about midnight, Villu Arak, the Skype spokesman who has been posting blackout updates, said: "The sign-on problems have been resolved. [However] Skype presence and chat may still take a few more hours to be fully operational."

According to user statistics gathered via a Skype RSS feed, the number of users connected to the service climbed throughout Friday afternoon, from about three million to more than 5.6 million in about six hours, a sign that Skype was coming back to life.

Individual users, meanwhile, reported that they were able to reconnect to the service - in some cases for the first time in almost two days - and that their connections remained stable, even if the Skype client was often slow to respond.

Although Skype first confirmed the outage Thursday, users writing on the company's own message forums began reporting problems connecting to the service as early as Wednesday afternoon. The company, a division of online auctioneer eBay, has not explained the blackout's cause, saying only that it was due to a "deficiency in an algorithm within Skype networking software."

Speculation that the outage was caused by a distributed denial-of-service attack or by some previously planned maintenance that Skype conducted late Tuesday have been regularly quashed by the company. "No... attack was related to the current sign-on issues in any way," Arak wrote.

Users, while relieved that the service was again alive, continued to blast the Luxembourg-based company for disrupting their business and personal communications.

A user tagged as "free skypeout minutes," who claimed to work for a Swedish company already heavily reliant on Skype's for-a-fee services, got to the point. "All plans to incorporate Skype into more of our procedures are now on hold indefinitely."