Standards Watch: IPv6 Leveling the Playing Field?

As debates boil about whether a future shortage of IP addresses threatens certain countries' participation in a global economy, foreign governments are putting research dollars into IPv6. Will the United States be left behind if it sticks with IPv4 for the long term?

Today, only five countries have an adequate number of IP addresses. "The goal should be to have every country, without distinction of its population or economy, sharing freely in the Internet's architecture," says Jim Bound, CTO of the IPv6 Forum (www.ipv6forum.com) and chair of the North American IPv6 Task Force, or NAv6TF (www.nav6tf.org).

Because the United States dominated the Internet early on, its ISPs, universities and companies have more addresses than they need for short-term goals. For the United States and other countries, addresses available through the various registries (ARIN in the Americas, APNIC in Asia-Pacific, and LACNIC in Latin America) are sufficient for present-day goals, yet 139 countries already struggle to meet address demands.

The utilization of Network Address Translation (NAT) also has extended the life of IPv4, as it enables multiple computers to connect to the Internet via a smaller number of global IP addresses. However, such practices have also served to compromise the end-to-end principle of the Internet, as packets and headers have to be intercepted and rewritten-"creating yet another step to manage from a performance perspective," notes Bound, adding that it makes end-to-end security very difficult: "If two people are to talk over VoIP confidentially, both ends need unique IP addresses where devices encrypt and decrypt on either end, without an ISP or vendor in the middle to look at the packets."

That, Bound maintains, is difficult today with IPv4, which requires either manual configuration of addresses or the use of DHCP. "NAT was created as a Band-Aid," he says. "It was not meant to be the heart of Internet infrastructure, as it has become."

Despite that fact, the 20-year-old IPv4 technology has proven quite resilient, which is why most of the equipment and content on the Internet is still based on it.

That means the United States may be able to rest on its laurels for the short term, but the fact that those on the other side of the digital divide are beginning to embrace IPv6 could be a driver to change. "While the U.S. could maybe pull off a sudden need for 10 million mobile addresses, Europe and Asia definitely could not," says Bound.

It's definitely a chicken-and-egg scenario, where content providers are waiting for demand, and service providers are waiting for a reason. "Until the Amazons and eBays of the world move to IPv6, ISPs will see little reason to move," concedes Margaret Wasserman, vice president of development with RFID company, ThingMagic, and one of two Internet area directors responsible for IPv6 working groups under the IETF, which defines the global Internet standards.

The move by Asian and European governments to fund IPv6 research could be an incentive for U.S. companies to take a closer look. "Our government believes our telecom companies are wealthy enough to fund their own telecom research," says Wasserman, "but lack of vision and research into up-and-coming technologies could be detrimental to us down the road."

As a result, IP address allocation could become the biggest quagmire in the global economy since the Y2K problem. Consequently, arguments regarding the number of global allocated and unallocated, used and unused IPv4 addresses, are heating up worldwide.

Is There a Really a Shortage?

The urgency of the issue stems in part from expectations about world population growth.

According to the United Nations, Internet technology can be considered "mass-market" in scope and size when it reaches at least 20 percent of the global population, which was estimated in 2002 to be about 6.3 billion. With 32-bit addresses, IPv4 can only accommodate about one-third of the Earth's population.

That is not a concern right now, as only 17.3 percent of countries (representing less than 15 percent of the total global population) have substantially adopted IPv4 address allocation.

However, it will become one if predictions by the U.S. Bureau of the Census come to fruition. By 2050, there will be more than 9 billion people on the planet, a marked increase from the 6,372,797,742 current inhabitants. To accommodate a large percentage of that number will require 128-bit addressing capabilities-especially if one considers what the future holds for IP-enabled devices.

Forrester Research projects that home devices and appliances, as well as mobile wireless equipment and automotive products, will be just some of the areas where IP will be embedded. That means cars, appliances and all devices could have networking applications accessible over the Internet. Couple that fact with the emergence of broadband access technologies, such as Ethernet-to-the-Home, Wi-Fi and SDSL, and it's easy to see why it's possible that in the future people will need more than the five or so IP addresses that IPv4 could afford the population: "With IPv6, every human on the planet could have as many as 10,000 IP addresses, thus enabling every desktop, every camera-every device-in the world to have a unique IP address," says Wasserman.

The possible applications that could emerge from the freedom to allocate addresses freely will open the floodgates to spending for Internet services. Forrester predicts the European Union's spending around the Internet will go from the 2001 figure of €77 billion to €2.2 trillion in 2006. With such huge demand possibilities, companies like NTT DoCoMo and now Microsoft-as well as 3GPP cell phone manufacturers like Nokia-are testing IPv6.

Roaming as the Key

Companies like NTT DoCoMo think mobility will be a key differentiator in the midst of that expected growth. Such visionaries consider mobility essential to the success of truly ubiquitous connectivity to the Internet.

Mobility requires flexibility in terms of configuration control (for both stateless or stateful configuration) so there can be roaming among WLANs and cellular networks.

When IPv4 was created, the Internet's design was such that it assumed hosts (computers) would be static, without any frequent change in location. That meant that IP addresses-used to identify the hosts and their location for routing-were used for long durations, as the location of the dependent IP address did not change very often.

With IPv4, users moving to new locations with mobile devices and connecting via Ethernet cable had to reconfigure to accommodate new IP addresses. That entailed learning about new default router IP addresses and discovering the IP addresses of new local DNS servers. Users then had to re-boot and hope that network applications would work the same way once IP addresses had been changed.

It boils down to the fact that IPv4 takes up twice as many addresses as would be needed with IPv6 in roaming applications: IPv6 provides location-independent identifiers, so users can send information to the mobile host without grappling with current locations of the device.

IPv6 employs two IP addresses per mobile host-one permanent IP address (also called home-address), used for identification; and another IP address that changes according to the location of the mobile host (called the care-of address, or COA). Then binding associations between these IP addresses can be kept at the home agent-the well-known location.

With IPv6 address space is unlimited so that each mobile device may have its own globally unique IPv6 home address and COA-thus eliminating the need for the special routers required with IPv4. IPv6 has also been designed to optimize handovers, thus minimizing latency and packet loss in hand-offs during real-time audio and video services.

Impact on Billing/OSS?

As IPv6 could open up new genres of applications, its huge address space could also enable innovative billing and OSS capabilities that will make new services more economically feasible.

Currently, billing complexity often increases with the number of applications because of DHCP, which IPv4 uses forto better utilization of existing address space. By assigning one user one address for a limited time, DHCP enables IP addresses to be renewed or given back to a pool of addresses for re-use.

Because billing information is collected from both the DCHP server and one or more application servers, identification of subscribers moving from one application to another requires usage data from application servers and/or network probes. In addition, the DCHP server state information must be accurately correlated by a mediation layer, often in real time.

"IPv6 will be very important to broadband and cable operators wanting to offer mobility to their subscribers," says Bryan Rank, mediation business development manager at Intec. "When you look at RBOCs and LECs, they don't yet have problems as they allow access into their networks, so they know who you are and where you are. They also generate new IP addresses that are not necessarily used outside their networks." However, robustness in addressing will be necessary when these operators want to give unique IP addresses to their customers when offering different access points into their networks.

Currently, users can access the network either through static (routable) IP addresses, which means they can be seen by everyone on the Internet (Web servers or mail servers), or they can go through non-routable IP addresses, getting access by sharing an IP address with other customers, such as when one cable modem in a house is used by multiple computers sharing the same IP address. "IPv6 migration allows a much larger range of address spaces, so those unique identifiers can be assigned more freely," Rank says.

Most billing and OSSs are adapted to IPv4, with mapping through DHCP and tagging of subscribers to their usage. However, with IPv6, billing could be simplified, according to Rank: "With IPv6, you get a MAC address [the hardware address for the piece of equipment accessing the network], which will help tie IP addresses to subscribers and equipment," he says. With IPv4 that is difficult, as IP addresses go back to a pool for re-use by someone else. "With IPv6, you could conceivably correlate that information so you know who used what address at any given time."

He concedes that ethical questions might be an inhibitor in the short term:

"With IPv6, having that one piece of information that allows you to see a person at any point of time and to know the address won't change makes it easier for the provider and for tying information back to billing systems," Rank says. "However, it makes it difficult for people to remain anonymous. It is harder to hide who you are with IPv6."