The chipsets are used in the production of modems that support Rockwell's high-speed "K56flex" 56-kbps modem technology.
Rockwell is locked in competition with U.S. Robotics to establish the de facto standard for 56-kbps modem communications. U.S. Robotics is currently merging with 3Com, another major communications manufacturer.
Some analysts doubt Rockwell's claims. "I don't really think that anyone has a clear majority at this point--USR is claiming a majority as well," noted Allen Leibovitch, an analyst with IDC. "At this point I don't think anyone can really claim victory."
Liebovitch also noted that although Rockwell is claiming that the K56flex has undergone the fastest production ramp-up in the company's history, U.S. Robotics got its chips on the market first, leaving Rockwell to play catch-up.
The two competing protocols are incompatible, although modem makers have promised buyers upgrades to the alternate standard if it becomes dominant.
A report last month by research firm Forward Concepts predicted Rockwell and Lucent, who developed the K56flex technology, will ship 65 percent of all 56-kbps modem chipsets this year.
The chipsets produced by Rockwell are of two major types: the chips used in consumer modems and those used in equipment sold to Internet service providers (ISPs). A set of each type must be used on opposite ends of the connection to obtain high-speed downloads. A similar scheme is used by U.S. Robotic's X2 technology for 56-kbps connections.