NTT Communications has begun offering a consumer IPv6 connection service that runs across any standard Internet access line and costs ¥300 ($2.50) per month. The service, which was launched in Japan earlier this month, is the first of its kind in the world, according to the carrier.

IPv6 is a newer version of the basic IP protocol used on the Internet for communication. Compared to IPv4, which is the current de facto standard, IPv6 offers several advantages. Chief among these is an address space that is large enough to accommodate all electronic devices so that they can be assigned permanent addresses. There are also security and QoS improvements built into IPv6.

To use NTT's service customers must install an access program, which is offered for computers running the Japanese version of the Windows XP SP2 operating system. The software maintains an IPv6 tunnel across a standard IPv4 Internet connection - fixed or wireless broadband or dial-up - to a server that links onto the IPv6 Internet. The software also manages the PC's IPv4 and IPv6 addresses. Windows Vista, Microsoft's upcoming new operating system, will include support built-in.

When a user accesses a resource on the Internet, such as a Web site, the PC looks up the site's IP address from it's domain name as usual. If an IPv6 address is available, a connection is established via the IPv6 tunnel. If not, the connection is made across the IPv4 connection as usual. In this way users don't need to manually switch between connections.

NTT provides users with two sets of global IPv6 addresses. One set is in a fixed range and allows users to, for example, assign a fixed address to a home music server so it can be accessed from anywhere on the Internet. The other set is a temporary address range. In both cases users have potentially millions of IP addresses to assign to devices around the home.

The availability of permanent IP addresses is a major enabler for the networked home. Today's temporary IPv4 addresses make it difficult to find devices such as home servers from out on the Internet. A permanent address will mean they can always be found. That's important for a wide range of consumer electronics products.

Sony's LocationFree TV is a device that connects to your TV antenna, video recorder and set-top box and can stream programming to clients outside of the home via the Internet. At present the device has to keep in touch with a Sony-run server so it can always be located, but a switch to IPv6 - both in the connection and device itself - would mean it's address on the Internet never changes.

The IDG News Service is a Network World affiliate.