IPv6 and distributed applications, by David Geer

David Geer

At different rates in different parts of the world, the next-generation Internet protocol, IPv6, is inching its way toward adoption. Asian countries are moving fastest, at least partly because their need for IPv6’s expanded address space is greatest, but efforts in the US and Europe also signal that the protocol’s detractors haven’t stopped its progress.

IPv6 got a boost from the US government in June, when the Office of Management and Budget (OMB) announced that all federal agency networks must be using it by June 2008. Such blanket directives, together with product development at industry and consumer levels, are giving a boost to the transition from the current Internet protocol, IPv4.

The Internet Engineering Task Force documented IPv4 in 1981 and deployed it two years later in a global switchover from Arpanet’s Network Control Protocol. The IETF documented IPv6 in 1998. But, the Internet community grew exponentially in the 15 years between 1983 and 1998. It became truly global as well as commercial, which made the switchover from IPv4 to IPv6 a significantly more complex problem.

“Though hardware that supports IPv6 is becoming available today, not everyone is making the decision to buy it because it costs a little bit more,” says Ed Doe, product line manager for network switching at Broadcom. Some legacy IPv4 hardware won’t come up for replacement for years, and moving to IPv6 involves opportunity-cost considerations. According to Doe, hardware vendors who are selling expensive IPv6-ready, IPv4-backward-compatible hardware currently stand to gain the most from IPv6 migration. “When you transition from IPv4 to IPv6,” he says, “the hardware has to support both protocols.”

The biggest obstacle to IPv6 adoption, he adds, has been finding a killer application to drive it.

Both IPv4 and IPv6 can empower distributed systems, according to Fred Baker, a fellow of Cisco Systems and IETF chair from 1996 through 2001. “The real problem with IPv4,” says Baker, “is the lack of IP addresses.” IPv4 uses 32-bit addresses, which yields a total of 4.2 billion unique IP addresses—fewer than the number of people on the planet. By comparison, IPv6 can assign 128-bit addresses, providing affording 2¹²⁸ or 3.4 × 10³⁸ addresses—essentially an infinite number that can support direct, end-to-end, peer-to-peer Internet applications for every one of 6 billion people and trillions of devices.

A few years ago, the proliferation of wireless devices and the Internet expansion in China looked sufficient to force the transition. However,network address translation, a technology devised as a temporary fix to extend IPv4’s address space, has since become widely deployed throughout the Internet. NAT devices support many private addresses through a single global IP address. They represent a controversial technology that the IETF has only grudgingly accepted.

Latif Ladid, president of the IPv6 Forum industry consortium, calls NAT “a primitive function” that impedes the innovations possible for a next-generation Internet. With NATs, public network traffic routes to a public IPv4 address, which the NAT then translates to private IP addresses on private computers. A client computer using NAT can generate an outbound connection but can’t accept an inbound connection. “So, NAT enables only a one-way Internet,” says Ladid.

True end-to-end peering, he says, requires each user to have an IP address: “End-to-end means a client becomes a server, as do servers when they talk to other servers using IP addressing point-to-point.” Giving each point an address will simplify the current client-server approach to peering, according to Ladid, and support distributed applications with less infrastructure.

Wireless e-commerce is one application area that will benefit from IPv6 deployment, according to Cisco’s Baker. When your mobile device has a globally recognized IPv6 address, network services can pick up your presence directly, along with personal information you’ve chosen to associate with that address. For example, if you’re running an errand and want directions to your destination, an available network-based service can immediately tell you where to go next as you join different networks along the way.

Distributed systems equipped with IPv6 can also play an important role in catastrophic emergencies. If an earthquake or hurricane hits, IPv6 supports unique addresses for cell broadcasting in mobile phone networks. You can deliver a message based on exact locations that tells people, “Move to higher ground; don’t stay where you are,” says Baker.

IPv6’s lavish address space means that distributed applications can extend to devices. For example, Denso Corp., a Japanese maker of windshield wiper systems, has teamed with Japan’s Intelligent Transport System Consortium, to test IPv6-enabled windshield wipers on taxicabs in Nagoya. Sensors report the use and speed of the wipers throughout the city via the Internet. “You can determine where rain is falling in different parts of the city,” explains Dale Geesey, vice president of consulting, v6 Transition, an IPv6 consulting and training firm. Dispatchers can then route more taxis to those parts of the city where the rain is heaviest.

IPv6 is expected to give hardware manufacturers a larger share of the service market. “People are saying all around the world, ‘Hey, our competitors are getting 20 percent of their revenues from services. Give me a plan to come up with revenues from services instead of just hardware,’” says Alex Lightman, CEO of IPv6 Summit, a consulting and training company. When hardware is IPv6 capable, IP can be used to track devices for warranties, upgrade and repair needs, and emergency assistance—providing a basis for service revenues.

Panasonic is shipping numerous IPv6-enabled consumer products, including webcams with two-way voice over IP, as well as printers, fax machines, copiers, and video cameras, says Lightman.

For companies using vast numbers of peripherals, these kinds of products make it easier to renumber devices (for example, when adding new devices to the network) or to give them dynamic IP addresses automatically, according to Lightman.

Smart homes will employ IPv6 chips in appliances, utility systems, and furniture to regulate them more efficiently. According to Paco Cabeza-Lopez, communications officer for the European Committee for Electrotechnical Standardization (Cenelec), the concept of the smart home is maturing and interest from consumer and industry markets is rising. Cenelec is standardizing essential technologies for smart home-based applications and architecture across Europe.

The IPv6 Forum is partnering with Cenelec. Ladid expects their joint efforts to drive large-scale deployment of new smart homes, which will provide a test bed for IPv6 applications.

Network equipment manufacturers, such as Cisco and Juniper, have included IPv6 capabilities in their products for years, and all major operating systems are implementing it. IPv6 proponents say that it will support a new world of distributed applications, and 2005 showed movement out of university and R&D testbeds into the marketplace. It’s a matter of space.

Copyright 2005 IEEE. Reprinted from the IEEE Computer Society's Computer magazine.

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