Back in 1981, the Internet Engineering Task Force (IETF) introduced what is now commonly known as Internet Protocol version 4, the next step in the development of the Internet. Two decades later, there is a legitimate concern that address space, or the sheer number of domain names, under v4 is running out. A movement has therefore begun to migrate to IPv6 mainly because it will offer more of this coveted space.
Despite the promise of more addresses being available with v6, however, it doesn’t appear that it is a transition that will happen soon, say some industry observers.
Version 4 arose from a U.S. Department of Defence need to improve its ability to share information internally. What could not have been fathomed back then was the staggering rate at which the Internet would grow. The well of available address space has subsequently been cut in half.
As it is currently structured, the American Registry of Internet Numbers (ARIN) is responsible for handing out IP addresses. The process now is relatively straightforward. An ISP must apply and justify to ARIN the amount of addresses that it would like. This wasn’t originally the case and addresses were being scooped up in large numbers by private institutions and enterprises that didn’t really need those volumes of numbers, but were allocated to them all the same, in the absence of a body that could govern their distribution.
Under IPv4, address space has a maximum of 32 bits. Within this system, there was a class system in place that was intended to help distribute addresses. Class A is a seven-bit network number, followed by a 24-bit host number; B is a 14-bit network number followed by a 16-bit host number and C is a 21-bit network number and is intended for very small network communities with 256 connections or less.
Version 6 will offer 128-bit IP addresses.
“One of the biggest issues around IPv4 and leading to ushering in IPv6 as quickly as it’s starting to take off is the fact that we’re simply running out of IP addresses (and) that’s the biggest reason for IPv6,” said Rob Davidson, technical specialist for Microsoft Canada in Mississauga, Ont. In its Windows 2000 and XP editions, Microsoft has already included support for v6.
Aside from increased address space (other benefits for moving to v6 include embedded security via IPSec and improved quality of service) bandwidth could even be increased or decreased from one transmission point to another for a given service or communication between users, Davidson said.
There is no immediate danger or evidence that suggests IPv4 is going to run out soon. There are already two ways, via tunnelling and dual software stacks from the PC to the server, that will make v4 and v6 interoperable.
But one IP specialist said that even if the transition was made within months, it wouldn’t change one of the core problems.
“Traffic (problems) are not directly related to v4 per se… and more related to content. Even if we switched to v6 tomorrow we would still have the traffic volume,” said Erone Quek, director of IP technology for Bell Canada in Toronto. Quek said part of the need to move to v6, which probably won’t begin for at least another two or three years, is due to emerging markets in Asia and India, VoIP and the growth of wireless devices, both of which consume IP addresses.
When it was suggested to Quek that addresses had been distributed in a haphazard fashion, he countered by arguing that ARIN has been strict with ISPs in regards to how many IP addresses they will allocate, and will only do so if the ISP can justify the quantity for which they have applied. He did agree with Microsoft’s Davidson’s view that the need for v6 is being driven by the potential for more address space becoming available.
Yet there is speculation that ISPs are facing specific challenges deploying v6. It is a more difficult implementation than originally anticipated and there really isn’t a killer application that has enticed either businesses or consumers.
“None of the service providers seem to be all that enthused about v6 addressing today. The interest really isn’t there yet in North America,” said David Kosiur, senior analyst for the Burton Group in Orcas, Wash. He characterized v6 as a new way of defining addresses and their subsequent distributions. Another way that v4 has seen its longevity extended is through classless inter-domain routing (CIDR), he added.
“I don’t get the impression from U.S. customers that they are concerned with v6 at this point. It still seems to be two or three years off from today. IPv6 is really being talked about in Asian countries and Europe,” Kosiur said.