Net's New Address Booker: IPv6

It's not yet time to hit the panic button, but when voice-over-Internet-protocol applications and services, and Internet appliances reach homes and businesses with a full head of steam, the current version of IP technology likely won't cut the digital mustard.

That's because IP Version 4, the present iteration, can't support the number of addresses required in the future world of pervasive IP, when consumers tap into the Internet with devices such as cell phones, Web pads and personal digital assistants.

Simply put, the well of IP addresses will eventually run dry if something isn't done.

Fortunately, something is being done, and it's called IP Version 6.

Originally recommended by the Internet Engineering Task Force in 1994, IPv6 (also known as "IPng") was proposed at a time when Internet engineers believed the 'Net would encounter danger once usage exploded.

The biggest difference between the two versions pertains to the number of bits each address contains. IPv4 houses 32 bits in each address, for example, while IPv6 is expected to carry a more impressive payload of 128 bits.

In its simplest terms, IPv6 will ensure that there's always a horde of IP addresses to go around. At 128 bits, IPv6 "will provide more addresses than anyone will ever need," said RiverDelta Networks Inc. CTO Gerry White.

"It's analogous to phone companies putting in new area codes," he added. "If more and more people get on the Internet and if VoIP takes off, that will take over a lot of addresses."

And it's not just PCs that need IP addresses — cell phones and Internet devices need them too, White said.

The world isn't presently on the brink of an IP-address crisis, however. That's because IP addresses can be multiplexed and shared among the majority of Internet users, White said.

That doesn't apply to cable-modem services, though, because they are always on.

"Cable gets burned on that. Even if it's not doing anything, the IP address for a cable-modem terminal is still active," White said.

IPv6 is designed to tackle that quandary, as well as provide a massively large base of addresses to quench the insatiable IP- addressing thirst of Internet-capable devices.

Still, plenty of work needs to be done before IPv6 can really happen. For starters, routers will require upgrading, protocol stacks will need changing and software must be rewritten to translate IPv4 data for the IPv6 world, and vice versa. And until IPv6 becomes ubiquitous, Web sites must still support both versions to ensure that browsers from both camps can decipher them, White said.

Then there's money. "All of the vendors are figuring out when it will make economic sense" to support IPv6, White said.

Cisco Systems Inc. has apparently already decided that it does. The company announced in mid-May that it had built IPv6 technology into its "IOS" routing software and had launched customer support and a suite of training courses to support it.

Cisco noted that home networks handling IP traffic for the new crop of gaming consoles and blossoming peer-to-peer applications eventually will require a multitude of global IP addresses — at least legions more than what IPv4 provides at present.

Also, 3Com Corp. unit CommWorks Corp said last week it has added IPv6 support to its Total Control 100 gigabit routers. That gear is currently available for trials, with a general launch slated for the third quarter of this year, CommWorks said.