1969. 4 mainframe hosts. US Dept of Defense employ Defense Contractors Bolt Beranek and Newman to build and provide ongoing support for the first computer packet-switching network running between the Stanford Research Institute near San Francisco and the research departments at the Universities of Los Angeles, Santa Barbara and Utah. The network is called the ARPANET - from the words Advanced Research Projects Agency.

1971. 20 hosts. Bolt Beranek and Newman establish the Email program using the protocol Username @ Hostname

1973. 40 hosts now connected to the ARPANET (including satellite links to London and Norway), with all Hostnames registered at Stanford. Work on a new system, employing the TCP/IP protocols commences. Jon Postel (1943-1998), researcher at the University of Los Angeles, oversees the RFC — Request for Comments — Editor to document each Transmission Control Protocol (TCP) port, and Internet Protocol (IP) address. Moves to University of Southern California in 1977 where he initiates IANA — the Internet Assigned Numbers Authority — today the central co-ordination function for the Internet.

1980. 200 hosts. IP version 4 protocol is released which allows for up to 4 billion individual IP addresses 0.0.0.0 - 255.255.255.255 and then up to 65535 TCP port numbers. The US National Science Foundation creates a second core network for institutions without access to ARPANET. Three Computer Science depts initially join. Vinton Cerf comes up with a plan for an inter-network connection between this CSNET and the ARPANET.

1983. 500 hosts. At the start of this year, US Dept of Defense make TCP/IP mandatory on every host. The University of California, Berkeley, include a modified version of TCP/IP in their commercial release of BSD UNIX. The Massachusetts Institute of Technology (MIT), in conjunction with DEC and IBM, use TCP/IP in developing a campus-wide model of distributed computing. Called a client/server system, where clients initiate communications by sending requests, and servers respond to such requests, providing the client with the desired data or an informative reply.

At the same time, numerous defense contractor networks and other university networks establish gateways to the ARPANET / CSNET. The ARPANET continues to be administered by Bolt Beranek and Newman under contract to the Defense Data Network's Network Information Center (DDN-NIC) at Stanford, and the CSNET by the National Science Foundation. Now being called the Internet — from internetworking — connecting networks regardless of their different individual protocols to these network backbones and thus indirectly to each other. Note, at this time unrelated commercial use was strictly forbidden.

1985. 2,000 hosts within 100 networks. Domain Name System introduced to simplify the sending of email which is now the major application on the Internet. Each computer's Hostname now includes a domain name. Information on a Hostname's associated IP address now stored within each computer network's Name Server(s), and just the domain name and the IP address(es) of the Name Server(s) registered in a Top Level Domain registry (TLD). Initial TLDs are .arpa, .mil, .gov, .org, .edu, .net and .com. All domain registrations are overseen by the Defense Data Network except .edu registrations which come under Jon Postel at USC. These generic domains are given out for free, along with free IP address blocks.

1986. 5,000 hosts. With the introduction of Country Code Top Level Domains, this registry system is significantly decentralized. Melbourne University in Australia given responsibility by the DDN-NIC for overseeing registrations in the .au domain. In the US, the National Science Foundation builds a third backbone network, the NSFnet, with high speed links to university networks right around the country.

1987. 25,000 hosts. The first email from China to Germany occurred, via the CSNET.

1988. 50,000 hosts. A non-profit company (a consortium of Michigan universities) in Ann Arbor Michigan called Merit Network, partnering with IBM and MCI, upgrades the NSFnet from 56Kbps to 1.5Mbps.Over 170 campus networks come online to the NSFnet. It takes over backbone duties from the ARPANET.

1989. 100,000 hosts within 500 networks and 4,000 domain names. CERN - the world's largest particle physics laboratory in Geneva, Switzerland - comes online to the NSFnet. Also JUNET - Japan's University Network. The first commercial ISP — The World — begins selling file copying access to private dial-up accounts.

1990. 200,000 hosts within 2,000 networks and 10,000 domain names. The ARPANET, having been fully overtaken and replaced by the NSFnet, is decommissioned and dismantled. The National Science Foundation starts a series of workshops and studies to enable the transition of the NSFnet to private industry. In preparation for this, Merit, partnering again with IBM and MCI, forms Advanced Network & Services (ANSnet) which over the next two years upgrades the NSFnet backbone from 1.5Mbps to 45Mbps.

1991. 500,000 hosts within 3,000 networks and 15,000 domain names. Network Solutions (a private company) is appointed by Defense Dept to administer the TLD root zone file which establishes those organizations worldwide who are responsible for each country's TLD registry. Also to work with Jon Postel in administering the generic domain registrations, .com, .org, etc.

1993. 2 million hosts within 15,000 networks. 25,000 domain names and 600 www sites. The National Science Foundation takes over funding responsibility for the Internet from the Dept of Defense. Private companies are becoming involved everywhere.

This same year, IANA issues the Asia-Pacific Network Information Centre (APNIC) with an initial 4 million IP addresses to allow it to become a regional IP address registry, using volunteer labour and donated facilities from a number of countries. Initially based in Tokyo, it now operates out of Brisbane, Australia, with the four major Internet Service Provider (ISP) members in Australia being Telstra, Optus, Connect (now owned by AAPT), and Ozemail (now iiNet).

1994. 3 million hosts within 25,000 networks. 50,000 domain names and 10,000 www sites. Beijing, China comes online as the Institute of High-Energy Physics (IHEP) in Beijing connects to the Stanford Linear Accelerator Center. ANSnet is sold to America Online (AOL). Numerous government institutions and commercial providers in the U.S. create their own backbones and interconnections on the Internet, preparing for an orderly transition.

1995. 5 million hosts within 50,000 networks. 100,000 domain names with an equal number of www sites. The NSFnet is dissolved on April 30, 1995. The high quality commercial networks (Tier 1 networks) including AT&T, Sprint, ANSnet, UUNet and others have formed a mesh network (rather than a single backbone network), interconnecting with each other on a settlement free basis i.e. no fees charged by the receiving network. Known as peering.

1996. 10 million hosts within 100,000 networks. 500,000 domain names / www sites.

1997. 20 million hosts within about 200,000 networks. 1 million domain names / www sites.

1998. US Dept of Commerce takes over responsibility for the Internet from the NSF. They contract with ICANN (Internet Corporation for Assigned Names and Numbers), a non-profit corporation at the University of Southern California, to oversee IANA. This includes regulating the root zone file which establishes those organizations responsible for the TLD registries - currently there are 312. Twelve organizations publish this file, and it is maintained by one of them — initially Network Solutions — then Verisign, who purchased Network Solutions in 2000. Verisign also retained responsibility for the .com and .net TLD registries.

1999-2002. In August 1999 the Wi-Fi™ (IEEE 802.11) alliance was formed to provide a high-speed wireless local area networking standard covering short distances, 30-100 metres maximum. In June 2001, this was followed by the WiMax™ (IEEE 802.16) Forum covering much greater distances, currently up to 50 kms. Next in 2002, the mobile wireless standards body 3GPP — 3rd Generation Partnership Project released 3GPP R5, a framework for the delivery of mobile Internet services complementing GPRS — General Packet Radio Service. GPRS had been commercially launched at 56Kbps on a GSM mobile phone network in the UK in June 2000, followed by a China network in August 2000. 3G was thus implemented via seamless GSM & W-CDMA networks (running at 384Kbps) with the option of much faster speeds using HSDPA.

2000-2001. 100 million hosts within about 300,000 networks. 40 million domain names. The Southern Cross Cable - a network of trans-Pacific telecommunications cables between Sydney, New Zealand, and California - is built and supported by Telecom New Zealand (AAPT) - 50%, Singtel (Optus) - 40%, Verizon - 10%. Overseas transmission costs - previously by satellite - drops by a factor of twenty-five - i.e. from 25 cents per megabyte to one cent (and less) per megabyte. Telstra subsequently invests heavily in the Australia-Japan Cable - it becomes operational in 2001.

2003. A system was released to allow domain names to contain foreign characters. A special syntax called Punycode was developed to employ the prefix "xn--" in the domain label and encode any foreign characters within the label from Unicode into a unique ASCII address — e.g. www.中.com would thus find itself encoded on name servers worldwide as www.xn--fiq.com.

2011. There are now 850 million hosts working within several hundred thousand networks getting service from one of the several hundred backbone Internet Service Providers (ISPs) that make up the core of the Internet. There are now 220 million domain names, with the .com domain registry - administered by Verisign - containing 99 million names, the .cn domain - administered by the Chinese Government's appointee CNNIC - 3 million names, and the .au domain - administered by Australian Government appointee AuDA - two million names. These figures are fairly rough estimates.

Click here for a Snapshot of its Current Hierarchy.

Click here for further Background of its History.