Networking Protocols
Networking protocols are sets of rules and standards that enable computers and other devices to communicate with one another over a network[^c3]. They define the format, timing, sequencing, and error control of data exchanged between network entities. The Internet and most modern data networks rely on a layered architecture of protocols that work together to deliver data reliably across diverse hardware and transmission media.
The foundation of modern networking is packet switching, a technique in which data is broken into smaller units called packets that are transmitted independently through a series of interconnected switches and routers[^c2][^c5]. This contrasts with the circuit-switched approach used by traditional telephone networks. Packet switching enables efficient sharing of network capacity, fault tolerance through dynamic rerouting, and the ability for many simultaneous communications to share the same infrastructure.
Two principal architectural models describe how networking protocols are organized. The Open Systems Interconnection (OSI) model, developed by the ISO in 1984, defines seven conceptual layers ranging from the physical transmission medium to the user-facing application[^c1]. The Internet Protocol Suite (TCP/IP), which is the practical framework used on the global Internet, consolidates these into four layers: the link layer, the Internet layer, the transport layer, and the application layer[^c4][^c6]. Each layer provides services to the layer above it and relies on services from the layer below, a design that allows protocols at different layers to evolve independently.
Key protocol families include the Internet Protocol (IP) for addressing and routing at the network layer, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) for transport-layer data delivery, and application-layer protocols such as HTTP, DNS, and SSH that enable specific networked services. Security protocols such as TLS and SSH provide encryption and authentication to protect data in transit. Routing protocols including OSPF and BGP enable routers to discover paths through complex networks and exchange reachability information across the global Internet.