A history of TCP and IP addresses: time is running out!

You may have heard or read that every computer, every phone and essentially every device connected to the Internet has a unique address, a sort of ID, if you will, that identifies it within a pool of millions of gadgets from all over the world. We’re talking about IP addresses. But what exactly are they and why are they important? Let’s take a look at their definition and history.

A bit of history of the Internet Protocol

The TCP (Transmission Control Protocol) is one of the fundamental protocols of the Internet. It was created between 1973 and 1974 by Vint Cerf and Robert Kahn.

vint-cerf_TCP (Transmission Control Protocol)_don burns_internet
Image courtesy of Johnny Ryan at Flickr.com

Many programs within a data network comprised of computers can use TCP to create connections between them, through which a data stream can be sent. The protocol ensures that data will be delivered to its destination without errors and in the same order they were transmitted. It also provides a mechanism for distinguishing different applications within the same machine, through what is known as ports.

The TCP supports many of the most popular Internet applications, including HTTP, SMTP, SSH and FTP.

The fourth version of the Internet Protocol: IPv4

IPv4 is the fourth version the Internet Protocol and it was the first version of IP to be extensively implemented. It was initially described in RFC 791, a document prepared by the IETF (Internet Engineering Task Force) in September 1981, which made the RFC 760 obsolete.

IPv4 is a data-oriented protocol used for communication between networks through packet switching, with the following features:

  • It’s a protocol of an unreliable datagram service.
  • It doesn’t provide any guarantee of data delivery.
  • It doesn’t provide guarantees for the correctness of data.
  • Its usage may result in duplicate or disorganized packets.

All of these issues are solved at the top level in the TCP/IP model, for instance, via TCP or UDP.

The main purpose of the IP is to provide a unique address to each system to ensure that any computer on the Internet will be able to identify others.

IPv4 uses 32-bit (4 byte) addresses, which limits the number of possible usable ones to 4,294,967,295 unique addresses. However, many of these are reserved for special purposes such as private networks, multicast, and so on. Because of this, the number of IP addresses that can actually be used is reduced. This has led to the creation of IPv6 -which is currently in development- as an eventual replacement for IPv4.

IPv6: The future of addresses

The Internet, based on an early design of the 1980s, has experienced a significant growth in the history of telecommunications, in both users and applications. IPv4 was launched in 1981, which was the first version of the Internet protocol that was widely implemented, and it was a breakthrough for networked communications, because at that time it was thought that was more than enough.

Subsequently, the short-lived fifth version of IP was developed, but it was only an experimental protocol that was aimed at improving the processing audio, voice and video streams.

To fix these shortcomings, since 1992 experts began to seek ways to improve and try to correct the deficiencies we mentioned before. The next generation of the Internet Protocol or IPng (Internet Protocol Next Generation) was proposed by the IETF, which culminated with the specification of a new IP protocol, successor to IPv4, formally known as the sixth version of the Internet Protocol (IPv6) which was released in 1999. This version is the future of communications, and it will help new devices to get connected.

In 1992, the Internet community had developed four separate proposals for IPng: CNAT, IP Encaps, Simple CLNP and Nimrod. After December of that same year, three other proposals appeared: the “PIP” (P Internet Protocol), the “SIP” (Simple Internet Protocol) and the “TP/IX”.

In the spring of 1992, the “Simple CLNP” evolved into the “TUBA” (TCP and UDP With Bigger Addresses and the “IP Encaps” into IPAE (IP Address Encapsulation).

Later, in the IETF meeting of July 1994, in Toronto, Canada, the leaders of said organization recommended the use of IPng and documented this in the RFC 1752 (The recommendation for the IP next generation protocol). On November of the same year, that recommendation was approved by the Internet Engineering Steering Group (IESG) which prepared a draft for a standard.

IPv6-IPv4_IP address_telecomunications_internet_don burns
Image courtesy of thierry ehrmann at Flickr.com

What happens when we run out of IPv4 addresses?

The exponential growth of the Internet is leading to the depletion of IPv4 addresses, a progressive decline in the number of available addresses. This issue has been a concern since the 1980s. As a result, it has become the driving factor in the creation and adoption of various new technologies, including CIDR and IPv6 addresses. It has also been a key element in the adoption of Network Address Translation (or NAT).

Since 2007, IPv6 has been seen as a long-term solution to the IPv4 address exhaustion, although its implementation is being done at a very slow pace. As the deadline of exhaustion of IPv4 addresses approaches, most vendors of devices and ISPs are starting to consider the widespread use of IPv6.

On February 2011, the IANA assigned the last available blocks to Regional Internet Registries, effectively depleting the pool of available IPv4 addresses.


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