Potential Impacts on Communications from IPv4 Exhaustion & IPv6 Transition
Robert Cannon, OSP.
FCC Staff Working Paper 3 (Dec 2010) discusses the Internet’s difficult migration to the new Internet Protocol version 6 (IPv6) address space. This migration is necessary because the original address space, IPv4, is nearly exhausted. Developed in the late 1970s, it has the capacity for about 4 billion unique addresses. It would have been hard to imagine in the 1970s that 4 billion addresses were not going to be enough. But by the early 1990s, Internet engineers recognized that the supply of addresses was relatively limited compared to likely demand, and they set to work designing a successor to IPv4. They developed a new Internet Protocol, IPv6, with a vastly increased address space: 340 trillion trillion trillion addresses.
Because broadband Internet access has become essential to the United States and the rest of the world, the exhaustion of IPv4 addresses and the transition to IPv6 could result in significant, but not insurmountable, problems for broadband Internet services. In the short term, to permit the network to continue to grow, engineers have developed a series of kludges. These kludges include more efficient use of the IPv4 address resource, conservation, and the sharing of IPv4 addresses through the use of Network Address Translation (NAT).
While these work-arounds provide partial mitigation for IPv4 exhaustion, they are not a long-term solution because they increase network costs and merely postpone some of the consequences of address exhaustion without solving the underlying problem. Some of these fixes break end-to-end connectivity, impairing innovation and hampering applications, degrading network performance, and resulting in an inferior version of the Internet. Moreover, these kludges require capital investment and ongoing operational costs by network service providers, diverting investment from other business objectives. Network operators will be confronted with increased costs to offer potentially inferior service.
The short term solutions are necessary because there is not enough time to completely migrate the entire public Internet to "native IPv6" where end users can communicate entirely via IPv6. Network protocol transitions require significant work and investment, and with the exhaustion of IPv4 addresses looming, there is insufficient time to complete the full IPv6 transition. This paper explains why, with the exhaustion of Internet Protocol version 4 (IPv4) addresses looming, there is insufficient time to complete the full transition to IPv6. The paper also explains how the implementation of IPv4 workarounds, while making that old protocol more efficient, are creating new problems of their own.