For most of Sunday and as of 5 a.m. today, computers on Northwestern’s network could not connect to Internet sites not run by the university.

The outage was because of technical problems at an Ameritech facility in Chicago and affected not only NU but several dozen other institutions in the Chicago area that depend on Ameritech for high-speed connections to the Internet, NU Information Technology officials said Sunday evening.

“It’s a major failure,” said David Carr, NU’s director of telecommunications and network services. “We’re by no means happy with the situation.”

Problems began early Sunday when Ameritech ran into trouble while performing maintenance on the computer system through which NU obtains its Internet connections to the outside world, according to Tim Ward, an IT senior network engineer.

Beginning around 2 a.m., the problems escalated — at one point stopping nearly half the campus from reaching non-NU sites — but most connections had returned to normal by about 10 a.m., Ward said.

Around 1:40 p.m. Sunday, however, NU’s entire computer system lost its Internet connection with the outside world.

By late afternoon, Ward said Ameritech estimated the connection would be restored by 7:30 p.m., but the time came and went without a fix. Ameritech then set new deadlines of midnight Sunday and 2:30 a.m. today.

Carr said Ameritech’s attempts to end the outage would “continue through the night.”

After repeated phone calls, Ameritech could not be reached for comment Sunday.

With most of the Internet unavailable, students were left frustrated at NU computer labs and in their dorm rooms.

Weinberg senior Jason Wennerholt was working in the library computer lab on an eight-page paper due today, but he said the Internet problems were slowing down his research.

“I wanted to get some more articles from the Internet, but I’m just going to write with what I have so far,” he said.

Jon Whitcher, who also was working on a paper, hoped for an extension. His paper is due Tuesday, but he said he wanted to complete his research before having to go downtown for a job interview today.

The network problems are “definitely a huge inconvenience — I can’t do any research,” said Whitcher, a Weinberg senior.

“The only convenience is that I may get an extension,” he added sarcastically.

Also at the library, Brice Blatz said all the material he needed for his art history paper was posted on NU Web sites. “That’s all I need, so thank God,” said Blatz, a Weinberg junior.

Working in the IT Information Center Sunday night, Speech senior Robert Mowry said he normally never gets more than a few phone calls, but he said he had received about 50 calls over a four-hour span Sunday night.

He said students who had called hadn’t been angry about the outage. “They’ve been kind of relieved it’s not something with their personal computer,” he said.

No news or description of the outage was posted Sunday on any of NU’s Web sites until about 10 p.m., when a notice appeared on HereAndNow’s site.

“We don’t disseminate (information about outages) through the Web servers,” Ward said.

During the day, the only Web site showing that an outage had occurred was NU’s Network Services Web site (http://rocky.nsg.nwu.edu/nsg/). A page on that site charts the last 24 hours of Internet connectivity of the computer that runs the site.

Explanations about the situation came in the form of messages Ward sent to an NU newsgroup throughout the day on Sunday.

McCormick senior Ed Sawma, a senior residential networking consultant who posted the notice on the HereAndNow site, said he and other res cons answered students’ individual questions about the situation but did not send messages to NU mailing lists, such as those in dorms.

“I think most people probably quickly caught on to what was going on,” he said. “Word spreads pretty quickly in the dorms.”

The Daily’s Ben Winograd contributed to this report.