protocol (network)

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A network protocol defines rules and conventions for communication between network devices.  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.

 

Modern protocols for computer networking all generally use packet switching techniques to send and receive messages in the form of packets - messages subdivided into pieces that are collected and re-assembled at their destination.Hundreds of different computer network protocols have been developed each designed for specific purposes and environments.

Internet Protocols

The 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.

Wireless Network Protocols

Thanks to Wi-FiBluetooth and LTE, wireless networks have become commonplace. Network protocols designed for use on wireless networks must support roaming mobile devices and deal with issues such as variable data rates and network security.

More: Guide to Wireless Network Protocols.

Network Routing Protocols

Routing protocols are special-purpose protocols designed specifically for use by network routers on the Internet. A routing protocol can identify other routers, manage the pathways (called routes) between sources and destinations of network messages, and make dynamic routing decisions. Common routing protocols include EIGRP, OSPF and BGP.

More: Top 5 Network Routing Protocols Explained.

How Network Protocols Are Implemented

Modern operating systems contain built-in software services 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.

Each packet transmitted and received over a network contains binary data (ones and zeros that encode the contents of each message). Most protocols add a small header at the beginning of each packet to store information about the message's sender and its intended destination. Some protocols also add a footer at the end.  Each network protocol has the ability to identify messages of its own kind and process the headers and footers as part of moving data among devices.

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.

More: How Computer Networks Work - Introduction to Protocols