AT&T; Long-Distance Calls Blocked : Communications: About half the calls that customers were trying to make were affected. The software problem took hours to correct.
If you tried to reach out on Monday, chances were about even that you did not touch anyone.
A mysterious problem gripped AT&T;’s giant long-distance network, making it impossible for many calls to get through. Instead, for hours on end, unlucky callers heard only a series of musical tones and the following tape recording: “All circuits are busy now. Please try your call later.”
The company said the problem was fixed by 8:30 p.m. PST, but spokeswoman Sally Sherwood said she could not provide any more details immediately on how the network was returned to normal.
“Obviously through a very long, laborious process they were able to detect the problem and fix it,” she said.
The difficulties were traced to software that runs computerized call-switching gear that AT&T; began installing in 1987, Sherwood said.
AT&T;’s diagnostic testing system first alerted the company to the problem around 11:30 a.m. PST.
Several hours later, engineers at the firm’s Network Operations Center in Bedminster, N.J., figured they had isolated the problem in the utility’s Signaling System Seven, a data network overlaying the talking path of telephone conversations. But it took several more hours to fix the system.
Linda McDougall, a spokeswoman in AT&T;’s Los Angeles office, explained that the SS7 network carries the calling number, the number called and the route of the call, but not the conversation.
She estimated that the problem affected about half the calls that AT&T; customers were trying to make on public lines.
Particularly hard-hit were companies that rely on 800 numbers to generate much of their business. At Avis car rental, for example, operators accustomed to juggling several calls per minute were staring at silent phones for as long as five minutes at a time. “We’re not getting any calls,” said one, who identified herself as Candy.
Increasing computerization has given the phone system far more versatility, enabling it to handle a growing load of calls, faxes and computer hookups. Call forwarding, call waiting and other custom services are all products of this computerization.
AT&T; and the regional operating companies insist that these additional services have not come at the cost of less reliability, but some experts have warned that the more complex the software systems, the more likely they are to have bugs that may pop up without warning.
On a normal business day, AT&T;’s long-distance network, the nation’s largest, handles between 80 million and 90 million calls. However, company officials said they believed the volume was significantly lower on Monday because of the Dr. Martin Luther King Jr. birthday holiday.
In Southern California, Al Harmon, owner of Aljo Fabric Protection Inc. of Van Nuys, said he was frustrated in a daylong effort to reach his distributor in Vacaville to tell him about an emergency that threatens a $16,000 to $18,000 fabric-protection contract with a Sacramento hotel.
“My manufacturer has shorted me on some product, and I’m afraid we’re going to lose the job, unless my distributor tells the customer that we’re going to be a week or 10 days going in,” Harmon said.
He started telephoning his Vacaville distributor at 6:30 a.m. Monday and continued throughout the day without success, Harmon said.
“I’m not outraged, but, Lord, this is my business. All of it is done on the telephone . . . I’m going to stay on it until I’m beat or I succeed.”
The Associated Press reported that a number of heavy users of toll-free lines experienced problems.
Cindy Sheffield, phone systems manager for the Marriott hotels reservation office in Omaha, said the problem was “devastating” for her office because it wasn’t receiving calls from prospective customers.
The office received only 10% of its normal call volume after the problem began, she said.
Fidelity Investments said callers had trouble getting through to the Boston-based mutual fund operator. “It did have quite extensive impact,” said spokeswoman Tracy Gordon.
American Airlines spokeswoman Mary O’Neill in Ft. Worth said that after 11:30 a.m. PST, the carrier experienced about two-thirds fewer calls than normal on its reservation lines.
Trans Mid-America, a marketing company in Omaha, specializing in temporary motor vehicle license sales, could not make any long distance or 800-number calls, said Florence Waymire, a vice president of the company.
“We’re dead in the water here today,” she said. The company has inbound and outbound telemarketing services, which “totally shuts us down.”
The problem did not affect the nation’s other major long distance carriers, MCI Communications Corp. and US Sprint.
Staff writer John Kendall contributed to this story from Los Angeles.
