Internet glitches slow smooth surfing.

Anyone who has spent time on the Internet lately has noticed "travel time" occasionally slows down. It might take hours or days to send off a message or an equal amount of time to receive an expected message or file. Some delays are due to massive traffic, but others come from system crashes that disrupt protocols -- mathematical rules that are supposed to allow for orderly communication.

George Varghese, a computer scientist at Washington University, St. Louis, has labeled this the "Murphy's Law" of distributed computer systems. His theory is that components with amnesia can fall into a muddled state and break down. Or, to paraphrase Murphy, if anything can go wrong in a protocol, it will.

Varghese and his colleagues are designing new protocols that either would help components without memory correct themselves or assist the devices in knowing the range of faults, or glitches, that can bring them down and how to adapt to them quickly. In concentrating on faults, Varghese is working against computing tradition, which always has stressed protocols and applications.

For perspective, a personal computer has a disk with memory. If you have saved everything on that disk, that data will survive a crash. However, there are many components of distributed computing -- many different machines pitching in for the same application -- that do not have memory. Devices like nodes and routers, which distribute messages, were developed without memory because of economics and the thought that memory wasn't needed for such items. Therein lies the rub.

With key words such as "amnesia," breakdown," and "muddled state," Varghese's theorem sounds like a recipe for a soap opera, but the analogy he is more interested in is chefs with amnesia. "A normal computer is like a single cook in a single kitchen. He cooks by himself and the application he comes up with is the food he serves. Let's say the application for the computer is the World Wide Web. In distributed cooking -- or computing -- you have a bunch of cooks in different...