ISPs in the U.S. are starting to test services that support IPv6, an upgrade to the Internet's main communications protocol. But advocates of the next-generation Internet technology say it may take until the year 2007 before U.S.-based multinationals are ready to deploy production IPv6 networks.

Developed by the Internet Engineering Task Force, IPv6 promises easier administration, tighter security and an enhanced addressing scheme over IPv4, the Internet's current protocol. IPv6, which uses a 128-bit addressing scheme, supports a virtually limitless number of uniquely identified systems connected to the 'Net, while IPv4 supports only a few billion systems because it uses a 32-bit addressing scheme.

Despite its promise, IPv6 has been slow to catch on because it requires a costly and time-consuming upgrade to the Internet's backbone and edge systems. The IETF finalized IPv6 in 1998, but few U.S. ISPs or enterprises have been testing the technology until now.

In October, the University of New Hampshire, the U.S. Department of Defense and the North American IPv6 Task Force announced deployment of the largest-ever IPv6 network for testing, training and software development purposes. Three ISPs - AT&T, Sprint and NTT - are supporting this nationwide test network, which is dubbed Moonv6.

Coordinators of Moonv6 say two more ISPs have committed to the project.

"U.S. ISPs are coming on board with IPv6," says Jim Bound, chairman of the North American IPv6 Task Force and an HP Fellow. "By February, five ISPs will have an IPv6 service for Moonv6. Two more major ISPs will be a part of our network."

Bound declined to identify which ISPs are joining the Moonv6 project. The only ISP that offers commercial IPv6 service in North America is NTT/Verio.

Bound said another sign of growing ISP support for IPv6 is that executives from AT&T, Sprint and NTT will speak at the U.S. IPv6 Summit, which will be held in Washington, D.C., Dec. 8-11.

As U.S. ISPs start supporting IPv6, forward-looking corporate network managers can start testing it.

"Most U.S. enterprises do not have IPv6 testbeds yet," Bound admits. "Starting next year we're going to be reaching out to the automotive industry, electronics, banking and manufacturing."

Yanick Pouffary, a member of the IPv6 Forum's Technical Directorate and a Distinguished Technologist with HP, says corporate network managers should require that all network equipment and software they buy is IPv6 compatible so that they're ready to transition to the new protocol in a few years.