Soaring Internet usage is bringing the U.S. phone system perilously close to gridlock by tying up millions of local phone lines every evening, say industry experts and analysts.
"It is like gridlock on a highway: If you are close to capacity, traffic still moves slowly, but just add a few more vehicles and you get gridlock," said Amir Atai, director of network and traffic performance at BellCore.
With Internet use rising at 42 percent a year, according to industry studies, phone capacity simply cannot keep pace.
"This type of (Internet) usage on our network is growing at 10 percent a month and we are watching it closely," said Nynex Corp. spokeswoman Susan Butta.
For phone networks, gridlock means fewer calls going through on the first try, more busy signals and even blocked calls, where perplexed callers hear nothing at all after dialing.
The bottleneck is essentially confined to local networks, and does not affect long distance carriers, experts say.
Industry studies suggest that if U.S. Internet penetration reaches 15 percent, it would force a $22 billion network investment by the regional Bells to support it.
Short-cut solutions exist, such as using filters to sort Internet calls from others based on their destination number.
If that idea catches on, it could open a huge market for firms like Lucent Technologies Inc. and Northern Telecom Ltd., which make the filters.
But regional Bells, indignant that Internet service providers do not have to pay access charges to reach Bell customers as long distance companies do, are reluctant to pay to sort out the problem.
"We found the problem is very severe in California and East Coast metropolitan areas. It is beginning to appear in some other areas," Atai said.
Cable modems running on upgraded coaxial cable -- designed for the high data rate of video pictures -- are expected to avoid congestion problems and should be available in volume late next year, analysts say.
To make matters worse, the peak hour for phone systems has now switched to 10 p.m. because of evening Internet use, throwing out the logistics of networks designed around pre- and post-lunch weekday calling peaks.
The advent of high speed protocols like Asymmetric Digital Subscriber Link, T1 phone lines and fast modems like those planned by U.S. Robotics will all tend to move Internet traffic away from the switched phone system.
While this is good news in the long-term, it discourages Bells from pursuing expensive fixes now, because they would become obsolete in just a few years.