Almost 20 years after Tim Berners-Lee posted a summary of his World Wide Web project onto the alt.hypertext newsgroup, there are more than two billion users worldwide, and billions more web pages. It has transformed the way we socialize, conduct business, and even changed the way we do science. But unfortunately, the number of available Internet addresses has not grown in the same time to accommodate these changes.
The number of Internet addresses is fixed because of the way the Internet operates: data is routed through the Internet in packets that use numeric addresses to encode its origin and its destination. The layer of communication at this level is called Internet Protocol (IP), originally developed by Vint Cerf, a program manager at the US Department of Defense Advanced Research Projects Agency and now Vice President and Chief Internet Evangelist of Google, USA, and member of numerous boards including Commissioner for the Broadband Commission for Digital Development in 2010.
IPv4 addresses, which are currently used, have a 32-bit integer value, capable of supporting only about four billion unique addresses. Twenty years ago, four billion seemed like a large number. In February 2011, however, the groups that manage IP addresses (Internet Corporation For Assigned Names and Numbers (ICANN) and the Internet Assigned Numbers Authority (IANA) announced that the last IPv4 blocks had been assigned to the Regional Internet Registries. And just two months later, the Asia Pacific Network Information Centre released its final batch of addresses to the region.
The solution to this long-anticipated problem is to replace IPv4 with IPv6, a 128-bit system that offers 240 billion, billion, billion, billion Internet addresses. IPv6 was first described in 1998, but deployment has been slow thus far. Now, with worldwide exhaustion of IPv4 addresses expected by the end of 2011, this is no longer the case.
Switching the LHC grid to IPv6
As IPv6 is phased in, it will coexist with IPv4. Adoption by Internet services and web companies has moved at a snail's pace - understandably so, as it requires changing the language of every device connected to the web. Currently, only 0.34% of all Internet users are capable of running on IPv6.
This is a huge problem that all computing grids will also have to tackle, as they require IP addresses to transfer data between users all over the world. If the computing grid at the LHC remained on IPv4, for example, "We would be unable to communicate with some of our users, in particular Asia Pacific," said Jean-Michel Jouanigot, CERN's IT Communication Systems Group Leader. "CERN would be unable to fulfill its mission, which is to give access to all our users."
"We started, more than a year ago, an aggressive plan to be IPv6 ready at the infrastructure level. This will last several more years, and will require significant effort to test all devices, systems, and adapt our network management framework. But all the applications - home made, public domain, and commercial - will need even more resources to be adapted," Jouanigot said.
Too fast, too soon
IPv6 was not implemented first because no one realized that the Internet would grow as quickly or become as large as it has today.
In the 1980s, although TCP/IP had been implemented in the US, European organizations were not as keen. At the time, there was resistance to American technology, and European industry was worried about TCP/IP. "They didn't want anything to rock the boat," said Ben Segal, a retired honorary member of CERN. This resistance did not perturb Segal, who introduced TCP/IP usage at CERN in the 1980s.
To Segal, this standard was simple, he recalled. The IP protocol is responsible for forwarding each data packet to an IP address via packet switching and TCP ensures error-free data delivery between applications.
In 1984, Segal proposed a pilot project to install TCP/IP protocols on CERN's key machines, to solve the connectivity problem between open and proprietary computer systems. TCP/IP combined with 'Internet sockets' - an API (Application Programming Interface) that enables software programs to use TCP/IP protocols - would prove to be a breakthrough.
Upon acceptance of Segal's proposal, computers around CERN could remotely communicate via a common framework. "External computer networking and distributed computing were hot," Segal said. Jouanigot, who has now worked at CERN for 20 years, helped build its first external TCP/IP networks with European institutions, helping TCP/IP to be widely adopted in Europe. In December 1988, Francois Fluckiger and Olivier Martin, both from CERN's IT Department, together with four other European TCP/IP enthusiasts, notably Daniel Karrenberg, created RIPE (European IP Networks), a forum to allocate IP addresses and help develop the Internet's infrastructure further.
"It created a series of standards on how to organize the Internet routing which is now used everywhere in the world," Jouanigot said.
When Tim Berners-Lee came on the scene, the stage was set. In 1991, Berners-Lee created the first web infrastructure, which ran on TCP/IP standards. "It was a miracle and a great time," Segal said.The web's power lay on TCP/IP's simple communication layer and the web browser's sophistication, regardless of the computer system used. But they had no idea that it would expand so rapidly. "The dream happened faster than we thought," said Segal.
Today, there are so many requests for IP addresses that companies requesting new IP addresses need to justify their reasons. "This is the trigger for change," Jouanigot said. "Large corporations have been hesitant on spending millions to change their network equipment. Although the protocol was defined some time ago, its implementation has been immature and not all devices are ready."
"This situation is analogous to the millennium bug problem," Jouanigot said, referring to the late 1990s, when it was thought computer systems would crash when reaching the year 2000. "Today's IPv6 task is an even larger job."
To help facilitate the switch, the Internet Society has set up World IPv6 day. On 8th June, the W3C, Google, Facebook, Limelight Networks, and others will pilot a global 24-hour 'test flight' of IPv6. The aim is to motivate Internet service providers, hardware makers, operating-system vendors and web companies to prepare for IPv6. Accepting this standard is the only way for the web to remain sustainable for future generations.
You can test if your computer network is IPv6 readyhere.