IPv6: The Quiet Revolution
June 9, 2003

By James Klein, Larta VOX Editor

Internet Protocol version 6 is coming! And has been for a long time.

Proponents cite a number of significant improvements provided by IPv6, but point to a coming shortage of IPv4 addresses as the primary reason for establishing a new protocol. Some observers, however, raise issues that could stall its implementation, including concerns over security systems, transition costs, control and distribution of addresses, and a lack of economic incentives, questioning whether the promise of IPv6 justifies the kind of resources required to make the switchover at this time. Whether critics are right or wrong, IPv6 is expected to gradually replace IPv4 over time, with the two coexisting for a number of years during a transition period.

Internet Protocol version 6 (IPv6) was designed to replace IPv4, the predominant protocol in use today. A "protocol" is a naming convention for assigning addresses. Every computer, server, Internet phone, or any device that connects to the Internet needs an address. IPv4 provides a maximum of 4 billion addresses. Supporters of IPv6 insist we need more, and that IPv6 is the only way to get them. Ipv4 is limited because it uses 32-bit numbers for its addresses, four octets of 8-bit blocks (238.14.246.4, for example), while Ipv6's uses 128-bit sequences, which makes the number of possible addresses practically limitless.

IPv6 has been called "…one of the most significant developments in the history of the communications industry…" by members of the Internet Engineering Task Force (IETF), which helped develop it, but most people have never heard of IPv6, don't know it's going to be implemented, and won't realize it if it is. Some proponents of IPv6 predict that end users will run the protocol without even noticing it as companies incorporate it into their programs.

The Internet may be a virtual environment, but you still need an address. Just as every house, apartment, and business needs an address that is expressed using a particularly convention, usually involving numbers and streets and cities and zip codes. Instead of streets and cities and zip codes, the Internet uses a naming system, a standard "protocol" that allows devices to find each other on the Internet. Sometimes the number of users, however, outstrips the capacity of the protocol to provide enough addresses. A good example is the New York City phone system.

In 1930, telephone subscribers in New York City had five-digit phone numbers.
Colorful two-letter exchange names (BUtterfield, WAverly, KLondike) were introduced in the 1930s and 1940s to provide enough telephone addresses for the growing number of subscribers. Exchange names were widespread by the 1950s, and many people associate these names with the period, immortalized in songs and films of the period, like "Pennsylvania 6-5000" and "Butterfield-8". Exchanges were phased out in the 1960s as the area code system was introduced to accommodate an astronomical increase in the number of U.S. telephone subscribers. When I grew up in New York City in the 1970s, it had one area code, 212. Now it has five.

Not Your Father's Internet

IPv6 has been in development for about ten years, which is how long proponents have been issuing dire predictions about the coming shortage of IP addresses. Even if IPv4 routing can be scaled to support a full IPv4 Internet, IPv6 supporters warn that the Internet will eventually run out of network numbers. "There is no question that an IPng (Internet Protocol Next Generation) is needed, but only a question of when," said Robert M. Hinden of the IETF in a 1995 paper.

When IPv4 was originally implemented, no one imagined that IP addresses would become scarce, but in the 1990s, many predicted the steadily increasing demand for addresses would exceed the ability of IPv4 to supply them. The IETF first raised concerns about a possible shortage of IPv4 addresses in 1992, and began an IPng program to determine the best solution. IPv6 was recommended by the IPng group and approved by the IETF in 1994. Since then, groups including the IETF, the Internet Society (ISOC), and IPv6 Forum have been relentlessly beating the drum for a switch to IPv6. Some companies and individuals have heeded the call, others have put their fingers in their ears, and others have said they simply don't like the beat.

In March of 2002, however, the IETF put a temporary halt on the development of all IPv6 migration tools so it could get a handle on the technology before a slew of standards caused problems. While the technology is stable today, IPv6 is not ready for worldwide adoption because of all the migration tools required, at least according to Margaret Wasserman, IETF next-generation and IPv6 transition working groups co-chair. As reported by Jim Wagener in internetnews.com, the IETF still needs to test all the tools before they will give their seal of approval, and called the development halt so they could at least address the tools already made. Critics say the development shutdown stifles innovation. The IETF has indicated that it will open up IPv6 for tool development this summer and expects worldwide IPv6 adoption sometime in the next couple years.
Has the well run dry?

Whether or how soon you believe the Internet will run out of addresses depends who you ask. Proponents of IPv6 say the Internet is a victim of its own success, and predict a global shortage of addresses within a couple of years. These observers fear devices soon won't be able to use the Internet at all, and see a time when the lack of IP addresses will stifle technology development and economic growth. Others expect it may take a decade or so before the number of devices connected to the Internet outstrips the supply of addresses, and say it's better to wait and see what happens in the near future before driving a switch to the new protocol.

The number of Internet users is expected by many to grow exponentially, particularly in Asia and developing countries. In addition, the number of IP addresses each user requires is projected to increase as new technologies emerge. New generation mobile phones, high-speed data access, wireless voice-over-Internet devices, peer-to-peer applications, as well as Internet-equipped vehicles and household appliances will all need individual IP addresses, multiplying the number of addresses required by each user. According to the U.S. Census Bureau, the world may be inhabited by as many as 9 billion people by 2050. If you count all personal and business communication and information systems, including vehicles and home appliances, each of those 9 billion people might be using dozens of devices, each with its own address, that connect to the Internet.

Besides providing more IP addresses, IPv6 offers many other benefits. IPv6 makes routing and automatic configuring easier, simplifies header formatting, improves support for extensions and options, increases flow labeling capability, provides for greater security, and consolidates authentication and privacy capabilities. IPv6's simplified header architecture and protocol operation could reduce operational expenses, but perhaps the most significant improvement offered by IPv6 is its address autconfiguration capabilities, which allows mobile devices to be quickly recognized as they move among networks. IPv6 is also friendlier to traffic engineering technologies, has mandatory multicast specifications, better support for ad-hoc networking, and other technical compared to IPv4. Even so, the greatest benefit of IPv6 continues to be its ability to provide a practically inexhaustible number of addresses.

Asia Left Out

Asian countries have the most to lose if IPv4 runs out of addresses, and therefore include some of the governments that are most active and vocal in supporting the switch to IPv6. China and India have already run out of IP addresses and are migrating to IPv6, with or without worldwide approval. Some predict there may come a time when there will be a "dual-track Internet" on either side of the Pacific Ocean, as Asia moves rapidly towards IPv6 while North America lags behind.

When IPv4 addresses were originally allocated, about 20 years ago, the U.S. and Europe grabbed most of them. The U.S. controls over 3 billion IP addresses, which represents about 70 percent of all IP addresses available. Asian countries were largely excluded from the address land rush. China and South Korea, for example, were allocated only about 38 million and 23 million IP addresses, respectively. China has fewer IPv4 addresses available than Sony Group. Last year, China had about 17 million Internet subscribers, while some project the figure to reach 62.5 million by 2007. In Japan today, current IPv4 address allocation is insufficient.

China and Japan are investing millions to develop IPv6. Both governments have pledged $32 million dollars to invest in network construction and testing, system development, application technology development and standardization. The Nikkei Electronics news service has reported that the Japanese firm Hitachi will become an Internet service provider (ISP) in China, and will be the first in the country, and probably the world, to use only IPv6 addresses for customers, although non-Asian makers such as Nortel, Cisco, Nokia and others have supported IPv6 in their products for some years. Japan has led the world in IPv6 implementation, especially in its use of protocol stacks.
"We anticipate that this demand [for IPv6] will be strongest in the Asia-Pacific region, which owns far fewer registered IP addresses than does North America. As Internet-accessible wireless devices and Internet use in general grow in Asia-Pacific, service providers targeting that region will seek to build IPv6 backbone networks. Gartner expects that by 2006, 50% of all carriers in this region will have IPv6 running in some portion of their networks," stated Lawrence Orans, senior analyst, Gartner, Inc., in a 2001 Cisco News article.
Supporters of IPv6 also raise humanitarian concerns, describing a worldwide digital divide between those countries, businesses and individuals who are able to acquire Internet addresses and those who can't, resulting in a shortage of IPv4 addresses that could hinder economic development in poorer nations.

Because so many issues have to be worked out in order to facilitate the switch to IPv6, temporary fixes were developed, such as Network Address Translation (NAT), to prevent a shortage of IP addresses. NAT allows a number of hosts to share a single IP address. Proponents of IPv6 emphasize the limitations of NAT technology, especially when used in peer-to-peer networks. NAT also presents challenges for applications that incorporate the host's IP address in the application-layer data, an issue particularly problematic for security protocols such as IPSec.

A Foregone Conclusion?

"We view IPv6 as inevitable," said Andy Ingram of Sun Microsystems, which implemented a dual stack IPv4-IPv6 architecture in the first release of its Solaris 8 system. A paper written by members of the Internet Engineering Task Force (IETF) stated that "The first (and most important) fact is that IPv6 is inevitable." Whether the critics are right or wrong, IPv6 may have gathered enough momentum to make it unstoppable. The ranks of IPv6 supporters have swelled to operatic proportions with a chorus of voices that includes groups like IETF, ISOC, and the IPv6 Forum, as well as ISPs, switching and router companies, and hardware and software producers.

HP, Cisco, NEC, Nokia, NTT, Ericsson, Sony, Hitachi, British Telecom, Matsushita, Sun Microsystems, Microsoft, Juniper, and many other companies have spent millions of dollars testing IPv6 technologies and integrating IPv6 capabilities into their products and services. IPv6 implementation programs have been developed for many different host operating systems and routers, including implementations by Apple, BSDI, Bull, Digital, Epilogue, FreeBSD, FTP Software, Hitachi, HP, IBM, INRIA, Interpeak, Linux, Mentat, Microsoft, NetBSD, Nokia, Novell, NRL, NTHU, OpenBSD, Pacific Softworks, Process Software, SICS, SCO, Siemens Nixdorf, Silicon Graphics, Sun, UNH, and WIDE, and router implementations by 3Com, 6WIND, Bay Networks, Cisco Systems, Digital, Hitachi, IBM, Merit (routing protocols), Nokia, NTHU, Sumitomo Electric, and Telebit Communications. Microsoft has been contributing to the IPv6 standardization effort since 1996. The Internet Assigned Numbers Authority (IANA), which is responsible for allocating Internet addresses has started issuing numbers based on IPv6. Sony plans to start shipping IPv6-enabled products in the fall of 2003.

The Internet needs an upgrade

Upgrades. You love them, you hate them, you can't do without them. Or can you? Sometimes I'm delighted to find all the wondrous new features in an upgrade and do bless the wise and benevolent seers who improved what I now realize was a shoddy and ill-equipped piece of software. More often, however, I am enraged as I'm forced to relearn applications I already mastered. The new versions are usually more complicated than the previous versions, which makes it even more fun. Simple commands are seemingly changed at random. I'm still irked whenever I use an activated table of contents in Microsoft Word as they changed the command from a simple, one-handed click of the mouse to an awkward combination of the control key with one hand and the mouse with the other. It got so that I wouldn't return email from my IT team when they issued requests to upgrade my computer. I'd eat at my desk for fear of running into them in the cafeteria. But proponents of IPv6 insist the transition will be smooth and untroubled.

Supporters claim IPv6 can be installed as a normal software upgrade in Internet devices and is interoperable with the current IPv4. Its deployment strategy is designed to not have any flag days or other dependencies. IPv6 is designed to run well on high performance networks and will also still be efficient for low-bandwidth wireless networks. In addition, IPv6 provides a platform for new Internet functionality that will be required in the near future.
IPv6 includes a transition mechanism that is designed to allow users to adopt and deploy IPv6. In addition, the Simple Internet Transition (SIT) is a set of protocol mechanisms implemented in hosts and routers, along with some operational guidelines for addressing and deployment, designed to make transitioning the Internet to IPv6 work with as little disruption as possible. SIT provides for an incremental upgrade and deployment of IPv6, with minimal upgrade dependencies, easy addressing, and low-cost start-up costs.

Not Everyone's Convinced

The primary reason given for supporting IPv6 is an expectation that the current address naming protocol, IPv4, will soon run out of available addresses, but a stagnant global economy and an excess capacity of bandwidth and networking equipment compel some critics to question whether IPv6 is as crucial as it was once thought to be.

Whether or not the new protocol is required at all has been the subject of some debate within the technical community. While some argue that IPv6 is required for the future growth of the Internet, there remains a sizable camp who argue that the protocol is "too little, too late" and that IPv4 with the addition of network address translation (NAT) offers a viable system for the future.

What proponents of IPv6 sometimes fail to mention is that the number of IP addresses actually used is very low compared with the theoretical total. IP addresses are used by a small number of the Earth's inhabitants. Temporary solutions have been able to fix most of IPv4's problems, and address its limitations, while some critics say IPv6 doesn't fix the system's biggest routing problems. Others have called IPv6 "a full employment act for software engineers."

Vint Cerf, the honorary chairman of the IPv6 Forum, has stated that most businesses are "pretty near" apathetic toward the problem of address depletion, but has also said that proponents faced similar challenges when they encouraged the transition from Arpanet to today's Internet, which also required administrators to overhaul their systems.

George Jetson in China

One of the rationales for IPv6 is the expectation that we'll all have numerous devices connected to the Internet - computers, printers, digital cameras, radios, IP phones, Internet-enabled toasters and web-connected robotic house pets. One of IPv6's most lauded features is its autoconfiguration capability, which is especially useful for consumers with multiple devices. While high-end consumers, computer geeks, Sharper Image shoppers, and George Jetson wannabes may surround themselves with web-connected paraphernalia, it is unlikely that billions of Chinese consumers will be able to afford all these gadgets any time soon, which undermines the figures given as the primary justification for IPv6.

Band-Aids

IPv6 has been delayed in part because temporary fixes such as network address translators and dynamic addressing have resolved the potential lack of IP address, while dual-stack approaches, which allow IPv4 and IPv6 to run on the same device, lessen the need for immediate implementation. While most agree temporary solutions are not as robust, feature-rich or comprehensive as IPv6, critics believe they may provide adequate solutions until a better plan comes along, but IPv6 supporters have warned that continuing to add temporary solutions to IPv4 will only encumber a system that wasn't designed to be a worldwide network in the first place.

NAT has been so successful that some believe IPv6 is unnecessary, but while NAT can be used to cleverly hide high numbers of private addresses behind a much lower number of public addresses, NAT has a number of performance and management problems that could cause problems for some applications, including many peer-to-peer networking programs. IPv6 proponents point out that NAT inhibits many forms of innovative network use, and presents very challenging operational problems when deployed on a global scale.

Some observers speculate it may be possible to reclaim addresses from organizations that no longer need them. However, this solution may require manual renumbering of address networks, which could be costly. A few organizations, such as Stanford University, have returned addresses, but this practice has yet to gain much momentum.

Economic Incentives Lacking

While most observers admit IPv6 has advantages that will improve business on the Internet, skeptics have raised economic issues in their arguments against IPv6, and even proponents admit that a lack of IP addresses alone is not necessarily a strong enough reason to drive the transition to IPv6. IPv6, an Internet Evolution, a paper by the IPv6 Forum, which has "a clear mission to promote IPv6", states that "While the primary reason for the next generation protocol was increased address space, this alone is insufficient to drive an economically sounds transition strategy."

The IPv6 Forum paper explains that IPv6 may be able to be used to create new revenue streams, but doesn't detail what those revenue streams will be, and recognizes that IPv6 is essentially a software upgrade, which will require users to learn and relearn certain features. Cost reductions are cited in the paper, but transition costs are equally significant: "…there is a substantial increase in the theoretical spending for IT (with the adoption of IPv6), which can be directly attributed to the transition costs (new equipment, application upgrades, training)…" The paper goes on to admit that adoption of IPv6 among Internet service providers has been lackluster. "For the ISP, particularly in North America, adoption of IPv6 has generally not been a hot topic. The potentially high cost of transition for the ISP, accompanied by a serious lack of business drivers, has not precipitated a great deal of interest of the telecoms."

The issue of transition costs was raised as early as 1999. A CNET news article from 1999 addressed concerns that the costs of implanting IPv6 may outweigh the benefits: "…those pushing adoption of the protocol face tremendous obstacles because of the expenses businesses would incur to make the change. With IPv6, businesses would have to make massive infrastructure changes to their networks, which are costly and complicated."

"What I'm desperately trying to get the [Internet Engineering Task Force] to understand and face up to is that the solution they put forward is not going to be acceptable in the marketplace," said Noel Chiappa, a networking consultant and critic of IPv6, in the 1999 CNET news article.

Other critics have pointed out the lack of new killer apps that could whet consumers' appetites for IPv6, while others speculate that the new protocol system will open the door for many applications that haven't yet been created. Whether new applications emerge or not, IPv6 will likely provide greater efficiency running existing and future programs on the Internet.

Some observers have likened the dilemma faced by proponents of IPv6 to that faced by some engineers several years ago when they tried to warn governments and businesses of the Y2K problem. Even though the potential economic costs were astronomical, many businesses did nothing in the face of a potential looming disaster because the solutions were prohibitively complicated and expensive.

Say You Want a Revolution

Other issues have been raised in prelude to widespread IPv6 adoption. One issue involves the way address registries distribute IP address blocks to service providers and major customers. As history has proven, revolutions sometimes result in unexpected power-grabs as new leaders are absolutely corrupted by absolute power. Some critics of IPv6 have raised concerns about exactly who will be controlling the new addresses, how they will be distributed, and how privacy will be protected, given that the current system in place hasn't treated all countries fairly. Others warn that the same wasteful tendencies that plagued Ipv4 will affect Ipv6 if the same unfortunate policies are pursued, contending that while IPv6 has a seemingly limitless amount of address space, short-sighted and wasteful allocation policies could result in the adoption of practices that lead to premature exhaustion of the IPv4 address space.

IPv6 address numbers will be assigned and reassigned according to practices implemented by Internet Registries, who distribute IP address space to their members and customers. Local Internet Registries are overseen by National and Regional Internet Registries, who are ultimately controlled by the IANA.

Some observers have also raised privacy issues that should be addressed before full implemented of IPv6 takes place. Part of the IPv6 address is sometimes derived from the LAN address of the computer's network interface card, which could be misused to identify for the computer behind the IP address. It is feared that market researchers could use data-mining techniques to match addresses to individuals. The IETF has addressed this issue by developing an alternative solution in which the fixed identifier is replaced by a randomly generated number.

Some critics also describe flaws in routing directories that help servers on one part of the Internet find addresses on other parts. These routing tables were not designed to handle large volumes of traffic, and could experience problems given the steady growth of Internet usage. IPv6 does nothing to alleviate this problem.

As the debate continues, it's clear that IPv6 proponents would do well to convince more people of the advantages of IPv6. Whether they do or not, however, IPv6 may well become the standard for Internet addressing in the future.

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