Network Protocols: Meaning and Description

WHAT ARE NETWORK PROTOCOLS?

Network Protocols are a set of rules or procedures for sending information overthe network.

Network Protocols perform such functions as initializing and terminating communications sessions, addressing and routing packets, sending and broadcasting data, performing authentication or encryption,compressing data, and performing error corrections. Some Network Protocols have been specially made by specific vendors and accepted as the defacto standards by the industry but others were initially formed by independent bodies and then accepted and implemented by the vendors.

The most widely implemented network protocols are those relating to Transmission Control Protocol/Internet Protocol (TCP/IP) & the Internet.

TYPES:

Network Protocols are usually classified according to the layer they correspond to in the Open Systems Interconnection (OSI) reference model for networking. Types of network protocols include the following:

A. Data-link protocols:

Govern the framing of data, physical addressing of network nodes, and

media access control methods. For local area networks (LANs), these

primarily include Ethernet, Token Ring, and Fiber Distributed Data

Interface (FDDI). For wide area networks (WANs), they include

Point-to-Point Protocol (PPP), High-level Data Link Control (HDLC), frame relay, Asynchronous Transfer Mode (ATM), and X.25.

B. Network Protocols:

Handle link services and are responsible for addressing, routing, and error

checking. Examples include NetBEUI, Internetwork Packet Exchange (IPX), NWLink, and Internet Protocol (IP).

C. Transport Protocols:

Enable the establishment of sessions and ensure reliable flow of data. Examples include NetBEUI, Sequenced Packet Exchange (SPX), NWLink, and Transmission Control Protocol (TCP).

D. Application Layer Protocols:

Enable applications to access network services. Examples include Hypertext Transfer Protocol (HTTP), File Transfer Protocol (FTP), Telnet, and Simple Mail Transfer Protocol (SMTP), Simple Network Management Protocol (SNMP), Network News Transfer Protocol (NNTP), X.400, X.500, Server Message Block (SMB), and Network File System (NFS).