Communication and Network

Physical Connection

Twisted-pair cable(Telephone lines)

Twisted pair cable consists of two independently insulated wires twisted around one another. It is one of the cable type that used in telecommunication for very long time. Cable twisting helps to reduce noise pickup from outside sources and crosstalk on multi-pair cables. While twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network cable, most networks contain some twisted-pair cabling at some point along the network.

Coaxial cable

A coaxial cable be composed of two conductors that share a common axis. It used to carry radio signals, video signals, measurement signals and data signals. Coaxial cable are typically characterized with the impedance and cable loss. Although it more expensive than standard telephone wire, it is much less susceptible to interference and can carry much more data.

Fiber-optic cable

Fiber optic cable is a technology that uses glass (or plastic) threads (fibers) to transmit data. A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated onto light waves.
Optical fiber carries much more information than conventional copper wire and is in general not subject to electromagnetic interference and the need to retransmit signals. Now, most telephone company long-distance lines are made by optical fiber.

Computer Networks

Node

In a networks, node is a connection point, is either a redistribution point or a communication endpoint. In general, node has programmed or engineered capability to recognize and process or forward transmissions to other nodes.

Client

A client is an application or system that accesses a remote service on another computer system. Web browser is a client in its relationship with the computer that is getting and returning the requested HTML file.

Server

A server is a computer or device on a network that manages network resources. A network server is a computer designed to process requests and deliver data to other computers over a local network or the Internet, it is include Web servers, proxy servers, and FTP servers.

Hub

Hub is a common connection point for device in a network. In data communications, a hub is a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions. Hubs are commonly used to connect segments of a local area network.




Network Interface Card (NIC)

NIC is an expansion board which you insert into a computer so that the computer can connected to a network. Most NIC are designed for a particular type of network, such as protocol and media, although some can serve multiple networks.



Network Operating System (NOS)

NOS is an operating system that includes special functions for connecting computers and devices into a local-area network. NOS is also designed for client computers and provide functions so the distinction between network operating systems and stand alone operating systems.



Host Computer

Host computer is a computer system that is accessed by user who are working at a remote location. Basically, this term is used when there are two computer systems connected by modems and telephone lines.

Network Manager

Network Manager is a set of co-operative tools that make networking simple and straightforward. Either wireless or wired, network manager allows you to quickly move from one network to another network.