In both cases, subscribers to the companies' DSL, or high-speed digital subscriber line services, found themselves without Internet service, or with only intermittent connections. Both companies said they had fixed their problems by the close of the day.
But today's problems illustrate a persistent challenge facing the young broadband industry. Service outages have been a nagging problem for new broadband providers, and many companies are still in the process of upgrading their older networks to better handle high-speed Internet services.
Excite@Home, the leading Net-over-cable service, recently offered rebates and free service to customers in several California communities that had experienced outages or slow services due to network equipment failures.
Callers to Bell Atlantic's tech support line this morning were greeted with a message saying that the company was experiencing "widespread outages for InfoSpeed DSL customers in all areas except metropolitan New York."
A company spokeswoman said outages and intermittent service had affected slightly less than 2 percent of all Bell Atlantic DSL customers. That figure was lower than previous estimates, which had ranged close to 10 percent. The company would not divulge how many individual subscribers were affected.
A technical support representative earlier said the company had had reports of service outages from Boston, Philadelphia, Washington, and in parts of New Jersey. That list includes almost all of Bell Atlantic's territory where it offers high-speed Internet service, with the exception of New York.
The problems had been traced to a software upgrade Bell Atlantic made across its DSL network last night, spokeswoman Joan Rasmussen said. The company is not yet sure why the software caused the outages, she said.
Bell Atlantic restored service by 4:15 p.m. ET, Rasmussen said.
A Pacific Bell spokesman that that companies troubles stemmed from a failed router in the companies' ISP division, blocking DSL subscribers from connecting to the Internet. The router had been brought back online by midday, he said. The company did not release information on how many subscribers had been affected.
But several Pacific Bell subscribers said similar problems had intermittently kept them offline for as long as 10 days.
In several cases, the subscribers said customer service representatives had told them the problem lay with the ISP's router system, rather than the DSL lines themselves.
"It remains to be seen whether they've actually fixed it this time," said Mark Haythornthwaite, a DSL subscriber in Daly City, a suburb of San Francisco. "They haven't been able to get it right yet."
DSL is a technology that allows existing telephone lines to carry high-speed data and voice traffic simultaneously. It is the primary competitor to high-speed Internet access over cable TV lines.