by Mark A. Miller, P.E., President, DigiNet Corporation

Remember Y2K? As a quick refresher, on January 1, 2000, computers with clocks that could not handle a date past December 31, 1999 were in jeopardy of freezing up when the turn of the millennium occurred. Widespread havoc could have resulted, as systems that impacted virtually every aspect of our lives – including traffic lights, ATM machines, the air traffic control system and telephone central offices – could have potentially ground to a screeching halt. Fortunately, the telecommunications and computing industries had several years of advance warning, and savvy IT managers leveraged the situation to upgrade their servers, routers, and other systems before the deadline. Perhaps now we know what created the telecom bubble that burst a year or so later (but we’ll save that for another story).

Now, fast forward that clock to February 3, 2011. In ceremony in Montevideo, Uruguay, the Number Resource Organization (NRO) (www.nro.net), the global organization that coordinates the assignment of Internet addresses, announced that the last block of IPv4 addresses had been assigned on January 31, 2011. Does this spell the end of growth for the Internet, just as the industry has been gearing up for 4G wireless smart phones, and streaming video into every family room? Fortunately not, and just like the case of Y2K, the eventual exhaustion of the IPv4 address space had been predicted for some time, giving Internet architects plenty of time to react, and develop a course of action to address the challenge. But let’s back up and first examine the problem, before we look at the solution.

What we now call the Internet was actually born in 1969 as the ARPAnet, developed by the Advanced Research Projects Agency, which was affiliated with the U.S. Department of Defense. The original objective was to develop some means to connect all of the dissimilar government computers that were in use at that time, and the solution to that assignment evolved into what we now know as the Transmission Control Protocol/Internet Protocol (TCP/IP) suite. In short, the IP part of the suite provides for packet addressing and delivery, and the TCP part assures end-to-end message reliability. But the current widespread adoption of TCP/IP did not occur overnight. From the military applications that were developed in the 1960s, the protocol’s popularity expanded to other U.S. Government agencies in the 1970s, and finally into the commercial sector in the 1980s. The use of TCP/IP really took off in the early 1990s with the development of the World Wide Web, and today, it is safe to assume that an implementation of these protocols is now imbedded in every Internet connected device – from the most compact smart phone to the largest supercomputer.

So in a strange way, the Internet became a victim of its own success. When the original architects developed the addressing scheme (one of the key functions of the Internet Protocol), the scope of their vision was somewhat limited to the mainframes and terminals that existed in the 1960s. As a result, when they allocated a 32-bit field for the IP address space, the resulting 4.3 billion addresses (2³²) that were theoretically possible seemed more than adequate. But they could not have foreseen the rapid growth of the personal computer (now estimated at over 1 billion worldwide), or cellular telephone technology (now estimated in the range of 5 Billion subscribers worldwide).

So in 1993, the Internet Engineering Task Force (www.ietf.org), or IETF as it is commonly called, commissioned a task force to examine the address exhaustion, and thus have some solutions ready when that inevitable day (sometimes called the date of doom) arrived, and the last IP address was given out. That development effort became known as Internet Protocol, Next Generation, or IPng, with the resulting protocol named Internet Protocol version 6, or IPv6, to distinguish it from the original IPv4. The baseline specification for IPv6 was published by the IETF as Request for Comments (RFC) document 2460 in December 1998 (see http://www.rfc-editor.org/rfc/rfc2460.txt). Since that time, almost 300 RFC documents have been published that examine the intricacies of the new protocol and its implementation, such as IPv6 Addressing Architecture (RFC 2373), Mobility Support in IPv6 (RFC 3775), Basic Transition Mechanisms for IPv6 Hosts and Routers (RFC 4213), IPv6 over Social Networks (RFC 5514), and many, many more.

So the predicted date finally arrived, and the announcement in early February declared that that the last block of IPv4 addresses had been assigned. The official press release from the NRO announced that “This is an historic day in the history of the Internet, and one we have been anticipating for quite some time,” stated Raúl Echeberría, Chairman of the NRO. “The future of the Internet is in IPv6. All Internet stakeholders must now take definitive action to deploy IPv6.”

So what does definitive action really mean? That is certainly a valid question, but not one that can simply be boiled down to a few action items. We need to start with a good understanding of the shortcoming of the existing protocol (IPv4) plus the capabilities of the new protocol (IPv6); and then be in position to understand the format of these new addresses, how they are implemented within Internet-connected devices, which vendors are at the forefront of the technology, and how existing IPv4 systems can be transitioned to support IPv6.

The Rise of IPv6 is the first in a series of monthly conversations about the origins, evolution, attributes and challenges of IPv6. This is an extraordinarily important topic that will impact virtually every aspect of the networked world.

Author’s Biography

Mark A. Miller, P.E. is President of DigiNet Corporation®, a Denver-based consulting engineering firm specializing in the design of complex networks and multi-protocol internetworks. He is the author of many books on networking technologies, including the Internet Technologies Handbook, published by John Wiley & Sons.