Network protocols include mechanisms for devices to identify and make connections with each other, as well as formatting rules that specify how data is packaged into messages sent and received. Some protocols also support message acknowledgement and data compression designed for reliable and/or high-performance network communication. Hundreds of different computer network protocols have been developed each designed for specific purposes and environments.
Internet ProtocolsThe Internet Protocol family contains a set of related (and among the most widely used network protocols. Beside Internet Protocol (IP) itself, higher-level protocols like TCP, UDP, HTTP, and FTP all integrate with IP to provide additional capabilities. Similarly, lower-level Internet Protocols like ARP and ICMP also co-exist with IP. In general, higher level protocols in the IP family interact more closely with applications like Web browsers while lower-level protocols interact with network adapters and other computer hardware.
Routing ProtocolsRouting protocols are special-purpose protocols designed specifically for use by network routers on the Internet. Common routing protocols include EIGRP, OSPF and BGP.
How Network Protocols Are ImplementedModern operating systems like Microsoft Windows contain built-in services or daemons that implement support for some network protocols. Applications like Web browsers contain software libraries that support the high level protocols necessary for that application to function. For some lower level TCP/IP and routing protocols, support is implemented in directly hardware (silicon chipsets) for improved performance.
A group of network protocols that work together at higher and lower levels are often called a protocol family. Students of networking traditionally learn about the OSI model that conceptually organizes network protocol families into specific layers for teaching purposes.