Introduction Introduction * Data communication is the transfer of data from one device to another via some form of transmission medium. * A data communications system must transmit data to the correct destination in an accurate and timely manner. * The five components that make up a data communications system are the message, sender, receiver, medium, and protocol. * Text, numbers, images, audio, and video are different forms of information. * Data flow between two devices can occur in one of three ways: simplex, half-duplex, or full-duplex. * A network is a set of communication devices connected by media links. * In a point-to-point connection, two and only two devices are connected by a dedicated link. In a multipoint connection, three or more devices share a link. * Topology refers to the physical or logical arrangement of a network. Devices may be arranged in a mesh, star, bus, or ring topology. * A network can be categorized as a local area network (LAN), a metropolitan-area network (MAN), or a wide area network (WAN). * A LAN is a data communication system within a building, plant, or campus, or between nearby buildings. * A MAN is a data communication system covering an area the size of a town or city. * A WAN is a data communication system spanning states, countries, or the whole world. * An internet is a network of networks. * The Internet is a collection of many separate networks. * TCP/IP is the protocol suite for the Internet. * There are local, regional, national, and international Internet service providers (ISPs). * A protocol is a set of rules that governs data communication; the key elements of a protocol are syntax, semantics, and timing. * Standards are necessary to ensure that products from different manufacturers can work together as expected. * The ISO, ITU-T, ANSI, IEEE, and EIA are some of the organizations involved in standards creation. * Forums are special-interest groups that quickly evaluate and standardize new technologies. * A Request for Comment (RFC) is an idea or concept that is a precursor to an Internet standard. |
All times are GMT +5. The time now is 11:09 AM. |
Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.