A report on File Transfer Protocol

Illustration of starting a passive connection using port 21

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

- File Transfer Protocol
Illustration of starting a passive connection using port 21

33 related topics with Alpha

Overall
A Simplified TCP State Diagram. See TCP EFSM diagram for a more detailed state diagram including the states inside the ESTABLISHED state.

Transmission Control Protocol

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One of the main protocols of the Internet protocol suite.

One of the main protocols of the Internet protocol suite.

A Simplified TCP State Diagram. See TCP EFSM diagram for a more detailed state diagram including the states inside the ESTABLISHED state.
Connection termination
TCP sequence numbers and receive windows behave very much like a clock. The receive window shifts each time the receiver receives and acknowledges a new segment of data. Once it runs out of sequence numbers, the sequence number loops back to 0.

TCP is used extensively by many internet applications, including the World Wide Web (WWW), email, File Transfer Protocol, Secure Shell, peer-to-peer file sharing, and streaming media.

Network address translation between a private network and the Internet

Network address translation

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Method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device.

Method of mapping an IP address space into another by modifying network address information in the IP header of packets while they are in transit across a traffic routing device.

Network address translation between a private network and the Internet
Network address mapping
In bidirectional NAT the session can be established both from inside and outside realms.
How dynamic NAT works.

Some protocols can accommodate one instance of NAT between participating hosts ("passive mode" FTP, for example), sometimes with the assistance of an application-level gateway (see below), but fail when both systems are separated from the internet by NAT.

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

Communication protocol

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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.

Examples of protocols that use plain, human-readable text for its commands are FTP (File Transfer Protocol), SMTP (Simple Mail Transfer Protocol), and the finger protocol.

Example of a website with digital certificate

Transport Layer Security

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Cryptographic protocol designed to provide communications security over a computer network.

Cryptographic protocol designed to provide communications security over a computer network.

Example of a website with digital certificate
Simplified illustration of the full TLS 1.2 handshake with timing information.

In applications design, TLS is usually implemented on top of Transport Layer protocols, encrypting all of the protocol-related data of protocols such as HTTP, FTP, SMTP, NNTP and XMPP.

Diagram of the first internetworked connection

Internet protocol suite

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Set of communication protocols used in the Internet and similar computer networks.

Set of communication protocols used in the Internet and similar computer networks.

Diagram of the first internetworked connection
An SRI International Packet Radio Van, used for the first three-way internetworked transmission.
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.
Encapsulation of application data descending through the layers described in RFC 1122

Examples of application layer protocols include the Hypertext Transfer Protocol (HTTP), the File Transfer Protocol (FTP), the Simple Mail Transfer Protocol (SMTP), and the Dynamic Host Configuration Protocol (DHCP).

Application layer

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Abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network.

Abstraction layer that specifies the shared communications protocols and interface methods used by hosts in a communications network.

File transfer: File Transfer Protocol (FTP), Trivial File Transfer Protocol (TFTP)

Blue arrows depict implementation of SMTP variations

Simple Mail Transfer Protocol

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Internet standard communication protocol for electronic mail transmission.

Internet standard communication protocol for electronic mail transmission.

Blue arrows depict implementation of SMTP variations

The use of the File Transfer Protocol (FTP) for "network mail" on the ARPANET was proposed in RFC 469 in March 1973.

FTPS

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FTPS (also known FTP-SSL, and FTP Secure) is an extension to the commonly used File Transfer Protocol (FTP) that adds support for the Transport Layer Security (TLS) and, formerly, the Secure Sockets Layer (SSL, which is now prohibited by RFC7568) cryptographic protocols.

The Internet Messenger by Buky Schwartz, located in Holon, Israel

Internet

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Global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices.

Global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices.

The Internet Messenger by Buky Schwartz, located in Holon, Israel
T3 NSFNET Backbone, c. 1992.
ICANN headquarters in the Playa Vista neighborhood of Los Angeles, California, United States.
2007 map showing submarine fiberoptic telecommunication cables around the world.
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>

By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9, the HyperText Markup Language (HTML), the first Web browser (which was also a HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd), the first web server, and the first Web pages that described the project itself.

OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.

Operating system

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System software that manages computer hardware, software resources, and provides common services for computer programs.

System software that manages computer hardware, software resources, and provides common services for computer programs.

OS/360 was used on most IBM mainframe computers beginning in 1966, including computers used by the Apollo program.
PC DOS was an early personal computer OS that featured a command-line interface.
Mac OS by Apple Computer became the first widespread OS to feature a graphical user interface. Many of its features such as windows and icons would later become commonplace in GUIs.
The first server for the World Wide Web ran on NeXTSTEP, based on BSD.
Ubuntu, desktop Linux distribution
Linux, a unix-like operating system was first time released on September 17, 1991, by Linus Torvalds. Picture of Tux the penguin, mascot of Linux.
A kernel connects the application software to the hardware of a computer.
Privilege rings for the x86 microprocessor architecture available in protected mode. Operating systems determine which processes run in each mode.
Many operating systems can "trick" programs into using memory scattered around the hard disk and RAM as if it is one continuous chunk of memory, called virtual memory.
File systems allow users and programs to organize and sort files on a computer, often through the use of directories (or "folders").
A screenshot of the Bash command line. Each command is typed out after the 'prompt', and then its output appears below, working its way down the screen. The current command prompt is at the bottom.
A screenshot of the KDE Plasma 5 graphical user interface. Programs take the form of images on the screen, and the files, folders (directories), and applications take the form of icons and symbols. A mouse is used to navigate the computer.

Network services include offerings such as file sharing, print services, email, web sites, and file transfer protocols (FTP), most of which can have compromised security.