“By 2010 we will have run out of IP addresses if we don’t do something about it,” Vint Cerf, Google’s chief Internet evangelist and the man commonly referred to as “the father of the Internet,” told ReadWriteWeb last month. (Video embedded below.)

With the number of Internet-enabled devices particularly mobile phones soaring, very few IP addresses remain vacant, and with only about 20 per cent of the world connected to the Net, that’s a problem. And consumers, if you think this doesn’t affect you, think again. That latest gadget you bought – is it IPv6 compatible?
TCP/IP: So, what’s it all about anyway?
To fully understand IPv6 we need to take a look at TCP/IP and this means a quick trip back in time.
It all started way back in 1969, when the Advanced Research Projects Agency Network (ARPANET) was using a transmission protocol known as the Network Control Protocol(NCP) to transmit data across networks. Protocols, if you think of them as languages, are needed so that networks and computers can talk to one another.
Expensive, cumbersome and slow, NCP was found to be limiting and in 1973, the U.S. Defense Advanced Research Projects Agency (DARPA) initiated a research program, known as the Internetting project, to develop a better communication protocol.
The networks which emerged from this research became the basis for what we know as the Internet, and the protocols developed during this time became known as the TCP/IP Protocol Suite.
At its most basic level, the IP part ensured packets were routed to the right place by providing unique identifying numbers to all hosts connecting to the network, and the TCP part managed the transfer of that data.
On January 1, 1983 NCP was deemed obsolete when the ARPANET switched over to the new TCP/IP protocol suite, and as a result, marked this date as the official birth date [for some] of the Internet.
Getting to V1 from V6
According to the Living Internet, after Vint Cerf and Robert Kahn designed TCP/IP, DARPA contracted with three sites to develop operational versions: BBN, Stanford and the University College London, and four increasingly better versions of TCP/IP were developed: TCPv1, TCPv2, which then split into TCPv3 and IPv3. Stability finally arrived with TCPv4 and IPv4; the standard protocol we know and use today.
IPv4 uses 32-bit addresses, which limits the address space to 4,294,967,296 (232) possible unique addresses. But, as some of these are reserved for specific purposes, it reduces the total number available.
IPv6 with its 128 bit addresses increases the number of potential unique addresses to 3.4e+38 (a little bit more than 340 trillion, trillion, trillion). Additionally, it is designed to rectify issues found with IPv4 such as data security.
IPv6 is expected to slowly replace IPv4, with the two protocol systems expected to run simultaneously for many years.
But, what happened to IPv5?
Typically, the most often asked question when talking about IPv4 and IPv6 is what happened to IPv5? IPv5 was known as an experimental streaming audio/video protocol. According to Raffi Krikorian, a protocol named ST, the Internet Stream Protocol was created in the late 1970’s and two decades later revised to become ST2, at which point it was implemented in commercial projects by IBM, NeXT, Apple and Sun. ST and ST2 were already given that magical “5” notes Krikorian. Given it had little to do with the fundamental structure of IP addressing, IPv5 is not commonly recognized.
We’re running out of IP addresses
While the establishment of a single networking protocol was an important step toward maintaining order in the then new internetworked world, no one could have guessed the growth of the Internet, nor the number of IP addresses required to cover the ever growing demand.
“My only defense is that decision was made in 1977, at a time when it was uncertain if the Internet would work,” Cerf said recently, adding that a “128-bit address space seemed excessive back then.”
Watch our video below to get Cerf’s take on IPv6 – and why switching over is so important.
Recorded at SMX West 2009 by ReadWriteWeb
Vint Cerf image: Vint Cerf playing Spacewar on PDP-1
Credit: Flickr Joi