Computer network programming involves writing

computer programs A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program i ...

that enable processes to communicate with each other across a

computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...

Connection-oriented and connectionless communications

Very generally, most of communications can be divided into

connection-oriented Connection-oriented communication is a network communication mode in telecommunications and computer networking, where a communication session or a semi-permanent connection is established before any useful data can be transferred. The establish ...

, and

connectionless Connectionless communication, often referred to as CL-mode communication,Information Processing Systems - Open Systems Interconnection, "Transport Service Definition - Addendum 1: Connectionless-mode Transmission", International Organization for ...

. Whether a communication is connection-oriented or connectionless, is defined by the

communication protocol A communication protocol is a 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. The protocol defines the rules, syntax, semantics (computer scien ...

, and not by . Examples of the connection-oriented protocols include and , and examples of connectionless protocols include , "raw IP", and .

Clients and servers

For connection-oriented communications, communication parties usually have different roles. One party is usually waiting for incoming connections; this party is usually referred to as "

server Server may refer to: Computing *Server (computing), a computer program or a device that provides functionality for other programs or devices, called clients Role * Waiting staff, those who work at a restaurant or a bar attending customers and su ...

". Another party is the one which initiates connection; this party is usually referred to as "

client Client(s) or The Client may refer to: * Client (business) * Client (computing), hardware or software that accesses a remote service on another computer * Customer or client, a recipient of goods or services in return for monetary or other valuable ...

". For connectionless communications, one party ("server") is usually waiting for an incoming packet, and another party ("client") is usually understood as the one which sends an unsolicited

packet Packet may refer to: * A small container or pouch ** Packet (container), a small single use container ** Cigarette packet ** Sugar packet * Network packet, a formatted unit of data carried by a packet-mode computer network * Packet radio, a form ...

to "server".

Popular protocols and APIs

Network programming traditionally covers different layers of OSI/ISO model (most of application-level programming belongs to L4 and up). The table below contains some examples of popular protocols belonging to different OSI/ISO layers, and popular APIs for them.

References

* W. Richard Stevens:

UNIX Network Programming Unix Network Programming is a book written by W. Richard Stevens. It was published in 1990 by Prentice Hall and covers many topics regarding UNIX networking and Computer network programming. The book focuses on the design and development of netwo ...

, Volume 1, Second Edition: Networking APIs: Sockets and XTI, Prentice Hall, 1998, {{reflist Computer programming Inter-process communication Computer networks

Connection-oriented and connectionless communications

Clients and servers

Popular protocols and APIs

See also

References