26.1 Network Terminology

   

The area of computer networking and communications is full of terminology. This chapter is focused on some basic terms that are commonly used in daily life.

Local and Wide Area Networks

All networks fall into one of the two main categories. A LAN is a network that spans over a limited distance within a single site. The communication links used in LANs are of relatively high speed, from 10 Mbits for older Ethernet LANs to gigabit speeds for the newer Ethernet LANs. LANs are usually privately owned and used to transfer large amounts of data. Usually a LAN uses a broadcast mechanism for data transfer and is connected by a continuous media.

WANs cover large geographical distances and usually connect LANs to each other. Communication speed is slow compared with LANs. Different types of communication mediums are used in WANs, such as telephone links, satellite, wireless, and fiber optic cables. Typical examples of WANs are the Internet and ATM machine networks used by banks and financial institutions.

Due to different types of communication media, equipment used in LANs and WANs may be of different types. A LAN may require only a cable connection and a network interface adapter for a computer to be connected to a network. On the other hand, a WAN needs sophisticated equipment such as routers for interconnection.

Protocol

A protocol is a set of rules and regulations that govern communication between two computers attached to a network. It may be thought of as a human language where two persons can talk to each other once they know a common language.

Host

A host or node is a computer attached to a network. A host may be an HP-UX system, a PC, or a network device such as a router.

Physical Medium

Physical medium is the communication medium that connects devices in a network. In the simplest form, it is coaxial or twisted pair cable used in LANs. Other media are fiber optic cables, satellite links, and microwaves in wireless LANs.

Network Interface Adapter

A network interface adapter is installed inside a computer. It is used to connect a computer to a physical medium.

Bandwidth

This is the data transfer capacity of the physical medium used to connect hosts in a network. The greater the bandwidth, the faster the data transfer rate.

Client and Server

A client is a system or a user program that requests a service from a host on the network. A server is a host or a software program that responds to a request from a client. Most of the communications on a network take place between a client and a server, and the applications are known as working in client-server mode.

Route

A route is a data communication path between a source and destination host on a network. A route is used to transfer data within two nodes and may be either statically defined or calculated depending on network conditions.


   
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HP Certified
HP Certified: HP-UX System Administration
ISBN: 0130183741
EAN: 2147483647
Year: 2000
Pages: 390
Authors: Rafeeq Rehman

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