MCI is providing a direct connection between its commercial Internet backbone and Moonv6 , the world's largest test bed running IPv6, an upgrade to the Internet's main communications protocol.

MCI confirms that its participation with Moonv6 brings the top-tier ISP one step closer to offering commercial IPv6 service here in the United States. Currently, the only ISP in the United States to offer this capability is NTT Verio.

An MCI spokesman said the ISP "today offers IPv6 capabilities on a custom basis in North America, Europe, Middle East and Africa. We are preparing the network to deliver IPv6 on a wider scale. Stay tuned."

MCI announced Monday that it has joined Moonv6, a joint operation of the University of New Hampshire, the U.S. Defense Department, the North American IPv6 Task Force and the Internet2 university consortium. The IPv6 test bed links approximately 80 servers, switches and routers located in sites from New Hampshire to California.

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

Other service providers - including AT&T, Chunghwa Telecom, France Telecom, KDDI and NTT - have participated in previous Moonv6 tests. However, MCI is the first ISP to directly connect its commercial Internet backbone to the Moonv6 test bed via a high-speed OC-3 link.

MCI direct connection between its MAE network exchange points and Moonv6 means that test bed participants can measure how well their products perform over native IPv6 links instead of tunneling IPv6 traffic over standard IPv4 pipes.

"Previous connections [to Moonv6] were not actual production networks, but rather non-commercial research networks," says Ben Schultz, who oversees Moonv6 testing as managing engineer at the University of New Hampshire's Interoperability Laboratory. "Overall, it's a significant milestone for IPv6 and a major leap forward for IPv6 testing in North America."

Among the network vendors that have been testing their IPv6 hardware and software products on the Moonv6 backbone are Cisco, Extreme Networks, Foundry Networks, Lucent and Microsoft.

"Prior to this announcement, anyone who wanted to participate in Moonv6 had to place equipment in New Hampshire or provision a circuit to New Hampshire or tunnel over Internet2," explains Tom Bechly, director of enterprise network engineering at MCI. "Our MAE service is a Layer 2 national overlay. We provisioned a circuit from our POP in New York to the New Hampshire Lab. We extended the reach of the test bed to any of our locations so that any of our MAE customers can participate natively for IPv6 testing."

MCI has donated the connection between Moonv6 and its MAE infrastructure. The native IPv6 connection is available immediately to all of MCI's MAE customers, which are primarily service providers. These customers have usage-based fees, so the cost to access the new Moonv6 connection will be negligible, Bechly says.

"We're donating this to UNH because we plan to test over this facility ourselves," Bechly says. "This connection gives us the ability to test our IPv6 services over the wide area."

UNH officials say they will conduct another round of Moonv6 tests in April.