Those of you who are as old as I am will remember the multi-year attempt to move the United States from the English system of measurements to the metric system. The most visible push came in the form of dual speed signs placed alongside highways across the country. As I recall, the top sign showed the speed limit in MPH while a lower sign expressed the same speed in km/h. The hope was that people would subconsciously work the metric numbers into their heads and one day all the MPH signs could come down without anyone caring. Well, that didn't happen, and after about seven years, those dual signs reverted back to the original expression of MPH. Total fail.
While the idea of replacing the archaic English system of feet, miles, pounds, quarts, pints, and inches was (and still is) a good one, the voluntary approach was completely wrong. There was no mandate that those dual signs would only be up for a few months before metric became mandatory. Hoping that people would magically stop using the units of measurement they grew up with was ludicrous. Canada, on the other hand, made their switch compulsory and today's Canadians are completely comfortable telling you, "It's 23 degrees Celsius out there, eh."
This brings me to IP Version 6 (IPv6). IPv6 has been around since the 1990s, and yet most networks are still predominately built around the much older and terribly out-of-date IPv4. In fact, every time I speak at a conference or users group, I ask for a show of hands as to how many folks have made the switch to IPv6. I am lucky if I get two hands out of 100 people.
The Internet Protocol (IP) can trace its roots back to the early 1970s and two gentlemen from UCLA, Robert Kahn and Vint Cerf. Not only are they the fathers of IP, but they can also lay claim to defining the Transmission Control Protocol (TCP). Although both protocols have undergone revisions over the years, they are still in wide use and continue to be the workhorses of the Internet and network communications. In fact, your Web browser used TCP/IP to take you to No Jitter and this article.
IP uses a 32-bit addressing scheme to identify network elements. Everyone reading this article should be familiar with the format xxx.xxx.xxx.xxx where xxx is a three-digit (0 – 255) decimal number (or a two-digit hexadecimal number for all you geeks out there). Along with a subnet mask, these four numbers designate the network and host of a network entity.
To demonstrate this, I ran ipconfig on my PC and discovered that my IP address is 10.11.228.58 with a subnet mask of 255.255.255.0. This tells me that I have a Class C IP address with a network address of 10.11.228 and a host address of 58.
32-bits allows for up to 4,294,967,296 (2^32) unique addresses. While that number may have seemed huge back in the day, it didn't take long for the world to exhaust every possible network and host pair, and it quickly became apparent that an overhaul to IP was needed.
IPv6 was primarily created to address (pardon the pun) the need for more IP addresses. By expanding the address size from 32 to 128 bits, IPv6 supports a maximum of 2^128 or 340,282,366,920,938,463,463,374,607,431,768,211,456 possible addresses. Now, I don't know where you come from, but up here in the Land of 10,000 Lakes, that's a mighty big number. According to Wikipedia, that number represents:
Approximately 5×10^28 (roughly 2^95) addresses for each of the roughly 6.5 billion (6.5×10^9) people alive today. In a different perspective, this is 2^52 addresses for every observable star in the known universe.
If that doesn't convince you that we will never run out of IPv6 addresses, there is nothing more I can say.
IPv6 addresses are generally written as follows, where xxxx is a four-digit hexadecimal number:
xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx
In addition to the much larger pool of addresses that IPv6 provides, it delivers efficiency, security, and performance improvements over IPv4. Version 6's techniques to preserve bandwidth while enhancing the ability to enable robust streaming services make it especially suitable for those of us in the business of real-time communications.
I wrote that the adoption rate of IPv6 has been slow at the enterprise level. However, technology manufacturers and software developers have been working hard for many years to ensure that their products support both IPv4 and IPv6. For instance, Microsoft has offered support for IPv6 since Windows 7 and Windows Server 2008. Look back at my Windows 8 ipconfig screen and you will see an IPv6 address even though I am not overtly using it for anything. It's there when I need it, even if the network I attach to has no use for it.
I primarily use an Avaya communications system for telephony, and my Aura 6.3 system is fully IPv6 compliant. I am not sure of exactly when Avaya introduced IPv6 into Communication Manager and many of its adjunct servers, but I know that some components have been IPv6 compliant since version 5.2. I am also positive that communications vendors such as Cisco, Microsoft, Mitel, and Unify have added support to their systems. Still, despite the extensive adoption of IPv6 into nearly every recent network-aware product, it's rare when I encounter anyone who has taken full advantage of it.
Who recalls the loss of the Martian orbiter back in 1999? One engineering team was doing all their calculations in English measurement units while another was expecting metric. That "simple" mistake cost the American taxpayers more than $125 million dollars as Climate Orbiter was hurled out of its Martian orbit and wound up circling the sun. That's one oops moment I hope to never personally experience. I've made some big mistakes in the past, but nothing nearly that expensive.
Although I have yet to hear of any major catastrophes due to IPv4 to IPv6 mishmashes, having two protocols that tackle the exact same problem is rarely a good thing. It's customary for the old version to go away when the new kid comes to town. Clearly, that has not been the case.
While it's still uncommon to find an enterprise that has deployed a full-blown IPv6 communications system, change is in the air. I have recently responded to or helped develop a number of RFPs that contain questions pertaining to IPv6. I expect that some were purely academic or check-the-box questions, but many did not feel that way. Enterprises are beginning to look forward and that means the eventual retirement of IPv4. They see the benefits and don't want to lock themselves in with ancient, out-of-date technology.
If I were king of the forest, I would pull a Canada and set dates where IPv6 became mandatory. Here in the world of communications, a good place to start would be the SIP carriers. After a designated drop-dead date, providers such as Verizon and Level-3 would only deliver SIP trunks via IPv6. Enterprises still on IPv4 could use a session border controller as an IP protocol gateway, but IPv6-compliant enterprises would accept those trunks as they are.
Eventually, through a series of planned IPv4 obsolescence dates, IPv6 would become as common as centimeters in Chilliwack or meters in Montreal. Celsius in Corner Brook? Liters in La Tuque?
Like many things in the world of communications, the bleeding-edge endeavors might be those outside the United States where public IPv4 addresses have been scarce for a number of years. As China, India, and other Asian countries make the switch to IPv6 out of both need and technological correctness, folks here in the United States will play catch-up.
Of course, we here in the States could lead the way with a "just do it" edict. All we need is a real king of the forest to lay down the law and make it happen.
Andrew Prokop writes about all things unified communications on his popular blog, SIP Adventures.
Follow Andrew Prokop on Twitter and LinkedIn!
@ajprokop
Andrew Prokop on LinkedIn
