Internet protocol suite

Internet protocol suite. It is the foundational conceptual model and set of communications protocols that enables internetworking and powers the global Internet. Often termed the TCP/IP model, it defines how data is packetized, addressed, transmitted, routed, and received across interconnected networks. Its development, spearheaded by American researchers, fundamentally shifted global telecommunications and underpins virtually all modern digital communication.

Overview

The suite provides end-to-end data communication by specifying how data should be formatted, addressed, and routed. Its design emphasizes robustness and flexibility, allowing diverse network technologies like Ethernet and Wi-Fi to interoperate. This architecture was a radical departure from the more rigid OSI model promoted by the International Organization for Standardization. The protocols are implemented in software across countless devices, from servers running Linux to smartphones using iOS.

Layers

The model is abstractly organized into four functional layers, a simplification of the seven-layer OSI model. The link layer deals with communication between directly connected nodes on a local network segment, such as within a single LAN. The internet layer, primarily using the Internet Protocol, is responsible for addressing and routing packets across multiple networks, forming an internetwork. The transport layer, with protocols like TCP and UDP, handles host-to-host communication and data flow control. Finally, the application layer contains protocols for specific process-to-process data exchange, such as HTTP for web traffic and SMTP for email.

Core protocols

The Internet Protocol is the principal protocol, defining IP addresses and the structure of datagrams for routing. The Transmission Control Protocol provides reliable, ordered, and error-checked delivery of a data stream, crucial for applications like the World Wide Web. In contrast, the User Datagram Protocol offers a simpler, connectionless service for speed-sensitive tasks like DNS queries. Other essential protocols include the Internet Control Message Protocol for diagnostic messages, the Address Resolution Protocol for mapping IP addresses to hardware addresses, and routing protocols like Border Gateway Protocol that direct traffic across autonomous systems.

Development and history

Its origins lie in research funded by the United States Department of Defense's DARPA in the late 1960s, aiming to create a resilient network for ARPANET. Key architects Vint Cerf and Bob Kahn authored the seminal 1974 paper outlining the protocols. A major transition occurred on January 1, 1983, known as flag day, when ARPANET permanently switched from the older Network Control Program to TCP/IP. Standardization was later managed by the Internet Engineering Task Force, with protocols documented in Request for Comments memoranda. The NSFNET's adoption in the 1980s catalyzed its spread beyond military and academic use.

Implementations and usage

A ubiquitous implementation is the suite integrated into the Berkeley Software Distribution, which popularized it in UNIX systems and influenced later operating systems like Microsoft Windows and macOS. It is embedded in the firmware of networking hardware from companies like Cisco Systems and Juniper Networks. Its usage is universal, forming the backbone for services from Amazon Web Services cloud infrastructure to the HTTPS connections securing online banking. The suite's scalability and openness were critical enablers for the commercial growth of the Internet and innovations like voice over IP and the Internet of Things.

Category:Internet protocols Category:Computer networking