LAS VEGAS -- The vice president of marketing at Pluris says the CEO of Nexabit is behaving like a 12-year-old. The Nexabit Networks CEO counters by claiming Pluris had rigged a dummy demo on the show floor. Such is life in the terabit networking field, as a handful of companies tout their next generation-routing products here at Networld+Interop.

Terabit routers, loosely defined, are the high-powered data switching and routing systems expected to follow on the heels of the gigabit systems now being sold by established vendors like Cisco Systems and Juniper Networks (although many companies suspect that Cisco and Juniper are developing terabit products of their own). But as the terabit vendors jostle for position, the question may not be who has the best product -- or when they will arrive -- but whether the market is big enough to support a growing field of competitors.

"A lot of venture capital has gone into these companies, but you have to wonder why," says Morris Edwards, manager of communications consulting at International Data Corporation. "There are too many companies feeding a finite market."

TERABITS, NOT TERADOLLARSThe size of the market is an open issue. BT Alex. Brown has estimated that the terabit routing market will reach $1 billion in the year 2000 and perhaps $5 billion by the year 2003. But other estimates are much more conservative. For example, the market opportunity could be as low as $100 million to $200 million in the next few years, according to other analysts, including Mr. Morris.

"Some people say it's a multibillion dollar market and other say it's multimillion dollars," says Chris Nicoll, director of infrastructure analysis with Current Analysis. "There are probably only about 1,000 units that can be sold, and there are seven or eight companies vying for the market. They're not all going to survive."

The companies that survive will enjoy substantial revenues. Terabit routers are not cheap: they are expected to start at about $50,000 and cost as much as millions of dollars for the high-end systems. And the Internet backbone, where terabit routers are expected to be installed, is not shrinking any time soon.

HOW REAL ARE THEY?Each of the terabit router companies is well-funded and fortified with quality engineering talent, but that's where the similarities stop. All of their products are marked by differences in architecture -- the engineering models that will be used to pump and route the vast quantities of data.

"There's an issue about how you compute performance," says Nexabit president and CEO Mukesh Chatter. "If somebody gets a chassis and multiplies it by X, is that the speed? It's like having 10 PCs on a network and calling it a supercomputer."

Mr. Chatter's comments were largely directed at Pluris, which is raising eyebrows with its "optical backplane," a system that uses fiber optics, rather than electrical circuits, to tie together the various gigabit switching cards that make up the core of their terabit router boxes. Avici Systems and Nexabit both use electrical backplanes. Pluris claims it can attain the best performance (up to 184 terabits/second) by stringing together its router boxes.

The rhetoric escalated on Tuesday, when Nexabit's Mr. Chatter and Pluris vice president of marketing Sam Halabi -- a Cisco alumnus -- both attended a panel on terabit routing held at the show. During the panel, the two argued about the viability of their respective products. After the panel, Mr. Halabi accused Mr. Chatter of copying Pluris features and falsely claiming they existed in the Nexabit product. "We say we have something and he just turns around and says, 'Yes, we do that too,'" says Mr. Halabi. "He's acting like a 12-year-old."

Mr. Chatter, in turn, accused Pluris of forging its demo on the show floor. "It's not the real box," says Mr. Chatter. "Their demo is not real."

Avici, Nexabit, and Pluris all claimed to be demonstrating products on the show floor. In one sense, Avici and Nexabit clearly hold an edge over Pluris -- they both have more funding and their products are already in trials with major telecom carriers. Pluris announced at NetWorld+Interop that its product was scheduled to go into trial with Deutsche Telecom in a few months. The actual Pluris product, however, is not scheduled to ship until the end of the year.

FAST TALKWhether or not the companies have products that are ready to ship is of tertiary concern to their investors. Avici has netted $72 million in funding, and the company is aiming to go public by the end of the year, according to CFO Ralph Goldwasser. Nexabit is also planning an IPO before year-end. The company has raised over $40 million. Pluris has raised $23 million in venture funding and is shooting for an IPO in the year 2000.

The competition is enough to entertain everybody but the customers, who are still awaiting a terabit routing product that actually works.

"There's lots of words, but not much delivery," says Vab Goel, vice president of IP networking at Qwest Communications. Mr. Goel is waiting for a terabit routing product that meets his needs, and he says he hasn't seen one yet.