The Internet Messenger by Buky Schwartz, located in Holon, Israel
Diagram of the first internetworked connection
T3 NSFNET Backbone, c. 1992.
An SRI International Packet Radio Van, used for the first three-way internetworked transmission.
ICANN headquarters in the Playa Vista neighborhood of Los Angeles, California, United States.
Conceptual data flow in a simple network topology of two hosts (A and B) connected by a link between their respective routers. The application on each host executes read and write operations as if the processes were directly connected to each other by some kind of data pipe. After establishment of this pipe, most details of the communication are hidden from each process, as the underlying principles of communication are implemented in the lower protocol layers. In analogy, at the transport layer the communication appears as host-to-host, without knowledge of the application data structures and the connecting routers, while at the internetworking layer, individual network boundaries are traversed at each router.
2007 map showing submarine fiberoptic telecommunication cables around the world.
Encapsulation of application data descending through the layers described in RFC 1122
Packet routing across the Internet involves several tiers of Internet service providers.
Number of mobile cellular subscriptions 2012–2016
As user data is processed through the protocol stack, each abstraction layer adds encapsulation information at the sending host. Data is transmitted over the wire at the link level between hosts and routers. Encapsulation is removed by the receiving host. Intermediate relays update link encapsulation at each hop, and inspect the IP layer for routing purposes.
Conceptual data flow in a simple network topology of two hosts (A and B) connected by a link between their respective routers. The application on each host executes read and write operations as if the processes were directly connected to each other by some kind of data pipe. After the establishment of this pipe, most details of the communication are hidden from each process, as the underlying principles of communication are implemented in the lower protocol layers. In analogy, at the transport layer the communication appears as host-to-host, without knowledge of the application data structures and the connecting routers, while at the internetworking layer, individual network boundaries are traversed at each router.
A DNS resolver consults three name servers to resolve the domain name user-visible "www.wikipedia.org" to determine the IPV4 Address 207.142.131.234
Creating a subnet by dividing the host identifier
This NeXT Computer was used by Tim Berners-Lee at CERN and became the world's first Web server.
Share of population using the Internet. See or edit source data.
Internet users per 100 population members and GDP per capita for selected countries.
Internet users per 100 inhabitants Source: International Telecommunication Union.
Internet users in 2015 as a percentage of a country's population Source: International Telecommunication Union.
'''Fixed broadband Internet subscriptions in 2012
as a percentage of a country's population''' Source: International Telecommunication Union.
'''Mobile broadband Internet subscriptions in 2012
as a percentage of a country's population''' Source: International Telecommunication Union.
Banner in Bangkok during the 2014 Thai coup d'état, informing the Thai public that 'like' or 'share' activities on social media could result in imprisonment (observed 30 June 2014).
Internet users by language<ref name=NIUBL-IWS>{{cite web|url=http://www.internetworldstats.com/stats7.htm|title=Number of Internet Users by Language|archive-url=https://web.archive.org/web/20120426122721/http://www.internetworldstats.com/stats7.htm|archive-date=26 April 2012|website=Internet World Stats, Miniwatts Marketing Group|date=31 May 2011|access-date=22 April 2012}}</ref>
Website content languages<ref name=UofCLBWApril2013>{{cite web|title=Usage of content languages for websites|url=http://w3techs.com/technologies/overview/content_language/all|work=W3Techs.com|access-date=26 April 2013|archive-url=https://www.webcitation.org/66ZQzUXh6?url=http://w3techs.com/technologies/overview/content_language/all|archive-date=31 March 2012|url-status=live}}</ref>

The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices.

- Internet

The Internet protocol suite, commonly known as TCP/IP, is the set of communications protocols used in the Internet and similar computer networks.

- Internet protocol suite
The Internet Messenger by Buky Schwartz, located in Holon, Israel

13 related topics

Alpha

Network Packet

Internetworking

Practice of interconnecting multiple computer networks, such that any pair of hosts in the connected networks can exchange messages irrespective of their hardware-level networking technology.

Practice of interconnecting multiple computer networks, such that any pair of hosts in the connected networks can exchange messages irrespective of their hardware-level networking technology.

Network Packet

The most notable example of internetworking is the Internet, a network of networks based on many underlying hardware technologies.

The Internet Protocol Suite, also known as the TCP/IP model, was not designed to conform to the OSI model and does not refer to it in any of the normative specifications in Request for Comments and Internet standards.

Encapsulation of application data carried by UDP to a link protocol frame

Internet Protocol

Encapsulation of application data carried by UDP to a link protocol frame
A timeline for the development of the transmission control Protocol TCP and Internet Protocol IP.
First Internet demonstration, linking the ARPANET, PRNET, and SATNET on November 22, 1977

The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries.

Its routing function enables internetworking, and essentially establishes the Internet.

Rack containing several enterprise class routers connected to multiple networks

Router (computing)

Networking device that forwards data packets between computer networks.

Networking device that forwards data packets between computer networks.

Rack containing several enterprise class routers connected to multiple networks
Home and small office wireless router
A typical home or small office DSL router showing the telephone socket (left, white) to connect it to the internet using ADSL, and Ethernet jacks (right, yellow) to connect it to home computers and printers.
A screenshot of the LuCI web interface used by OpenWrt. This page configures Dynamic DNS.
The first ARPANET router, the Interface Message Processor was delivered to UCLA August 30, 1969, and went online October 29, 1969

Routers perform the traffic directing functions on the Internet.

A router is connected to two or more data lines from different IP networks.

ARPANET logical map, March 1977

ARPANET

ARPANET logical map, March 1977
ARPANET access points in the 1970s
First ARPANET IMP log: the first message ever sent via the ARPANET, 10:30 pm PST on 29 October 1969 (6:30 UTC on 30 October 1969). This IMP Log excerpt, kept at UCLA, describes setting up a message transmission from the UCLA SDS Sigma 7 Host computer to the SRI SDS 940 Host computer.
ARPA network map 1973
Internetworking demonstration, linking the ARPANET, PRNET, and SATNET in 1977
ARPANET in a broader context

The Advanced Research Projects Agency Network (ARPANET) was the first wide-area packet-switched network with distributed control and one of the first networks to implement the TCP/IP protocol suite.

Both technologies became the technical foundation of the Internet.

Figure 2. The TCP/IP model or Internet layering scheme and its relation to some common protocols.

Communication protocol

System of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity.

System of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity.

Figure 2. The TCP/IP model or Internet layering scheme and its relation to some common protocols.
Figure 3. Message flows using a protocol suite. Black loops show the actual messaging loops, red loops are the effective communication between layers enabled by the lower layers.
Figure 5: Protocol and software layering. The software modules implementing the protocols are represented by cubes. The information flow between the modules is represented by arrows. The (top two horizontal) red arrows are virtual. The blue lines mark the layer boundaries.

The development of a complete protocol suite by 1989, as outlined in and, laid the foundation for the growth of TCP/IP as a comprehensive protocol suite as the core component of the emerging Internet.

The Internet architecture as seen by the INWG.

International Networking Working Group

Group of prominent computer science researchers in the 1970s who studied and developed standards and protocols for computer networking.

Group of prominent computer science researchers in the 1970s who studied and developed standards and protocols for computer networking.

The Internet architecture as seen by the INWG.

CCIT went on to adopt the X.25 standard in 1976, based on virtual circuits, and ARPA ultimately developed the Internet protocol suite, based on the Internet Protocol as connectionless layer and the Transmission Control Protocol as a reliable connection-oriented service.

The INWG continued to work on protocol design and formal specification until the 1990s when it disbanded as the Internet grew rapidly.

Decomposition of an IPv4 address from dot-decimal notation to its binary value

IP address

Numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.

Numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.

Decomposition of an IPv4 address from dot-decimal notation to its binary value
Decomposition of an IPv6 address from hexadecimal representation to its binary value

However, because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP (IPv6), using 128 bits for the IP address, was standardized in 1998.

Computers not connected to the Internet, such as factory machines that communicate only with each other via TCP/IP, need not have globally unique IP addresses.

Network Packet

Computer network

Set of computers sharing resources located on or provided by network nodes.

Set of computers sharing resources located on or provided by network nodes.

Network Packet
Common network topologies
A sample overlay network
Network links
Fiber optic cables are used to transmit light from one computer/network node to another
2007 map showing submarine optical fiber telecommunication cables around the world.
Computers are very often connected to networks using wireless links
An ATM network interface in the form of an accessory card. A lot of network interfaces are built-in.
A typical home or small office router showing the ADSL telephone line and Ethernet network cable connections
Firewalls
The TCP/IP model and its relation to common protocols used at different layers of the model.
Message flows between two devices (A-B) at the four layers of the TCP/IP model in the presence of a router (R). Red flows are effective communication paths, black paths are across the actual network links.
SONET & SDH
Asynchronous Transfer Mode
Routing calculates good paths through a network for information to take. For example, from node 1 to node 6 the best routes are likely to be 1-8-7-6, 1-8-10-6 or 1-9-10-6, as these are the shortest routes.
Partial map of the Internet, based on the January 15, 2005 data found on opte.org . Each line is drawn between two nodes, representing two IP addresses. The length of the lines is indicative of the delay between those two nodes. This graph represents less than 30% of the Class C networks reachable.

In 1974, Vint Cerf, Yogen Dalal, and Carl Sunshine published the Transmission Control Protocol (TCP) specification,, coining the term Internet as a shorthand for internetworking.

IP network delays can range from a few milliseconds to several hundred milliseconds.

Chantenay-Saint-Imbert railway station

Louis Pouzin

French computer scientist.

French computer scientist.

Chantenay-Saint-Imbert railway station

His work, and that of his colleagues Hubert Zimmerman and Gérard Le Lann, were acknowledged by Vinton Cerf as substantial contributions to the design of TCP/IP, the protocol suite used by the Internet.

Illustration of starting a passive connection using port 21

File Transfer Protocol

Standard communication protocol used for the transfer of computer files from a server to a client on a computer network.

Standard communication protocol used for the transfer of computer files from a server to a client on a computer network.

Illustration of starting a passive connection using port 21

Until 1980, FTP ran on NCP, the predecessor of TCP/IP.

It was never widely accepted on the Internet, and is now assigned Historic status by the IETF.