This two-part article presents IPv6, the next generation of the protocol that powers the Internet. The first installment of the article introduces IPv6 and discusses its raison d’etre. The second installment will provide a overview of some of its features and benefits, and the market outlook for IPv6.

IPv6 (Internet Protocol Version 6) is the name given to the next generation of the Internet Protocol. IPv6 will eventually replace IPv4 (Internet Protocol Version 4), the workhorse of today’s Internet. The Internet Protocol provides the envelope within which information is packaged and transported across the world-wide Internet. For example, when you connect to Lokvani.com from your computer, the content from Lokvani.com’s web server is sent to your PC packaged in IPv4 information packets. The Internet Protocol suite also provides the set of rules and procedures using which Internet-connected devices address each other and communicate with each other over the Internet.

Even though IPv4 is an established and entrenched technology today, it is over a quarter of a century old. The exponential growth in the number of devices connecting to the Internet, and the daily blooming of new applications for the Internet is pushing IPv4 to bulge at its seams, and it is anticipated that it will not be too long before the fabric bursts at its seams. IPv6 is the Internet Engineering community’s answer to IPv4’s problems. IPv6 addresses a number of issues with IPv4, while its design incorporates the lessons learned from the IPv4 experience.

IPv6 solves the address crunch in today’s Internet that is an inherent consequence of IPv4’s design. Consider a developing country which decides that a 4 digit zip code (about 10,000 towns) will meet its needs, based on its expectations of population growth and distribution. If the country experiences a sudden boom and population centers start proliferating everywhere, then the zip code system will have to be extended with more digits, if it is to be useful anymore. Now Imagine the Internet is that country and the devices attached to the Internet are the towns. The zip codes then correspond to what are known as IP addresses. Twenty five years ago, the designers of IPv4 decided that a 32 bit (binary digit) IP address would meet the needs of the Internet. This corresponds to about 4 billion addresses, even though address allocation practices limits the actual number to a few hundred million. This may appear to be a large number, but remember that the population of the US alone is about 300 million. Think about the variety of Internet-connected devices that one carries today, and how immensely popular and ubiquitous personal computers, cell phones, Personal Digital Assistants (PDA) and other Internet-enabled personal devices have become. Also, remember that new devices that sport net connectivity are announced every day, ranging from wrist-watches, photo frames, phones, radios, and refrigerators. The relentless proliferation of Internet endpoints points to an eventual exhaustion of the IPv4 address space. IPv4 has been coping with this explosion of Internet end points in the short term using certain address conservation technologies such as Classless Internet Domain Routing (CIDR) and Network Address Translation (NAT). IPv6 provides a longer term solution to the lurking address famine by providing a 128 bit address space. This works out to an unimaginably huge number of addresses (a number with 38 zeros at the end), and corresponds to an average of trillions of addresses for every person on the planet!

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