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Introduction to Networks. Network. A communication system that enables many users to share computer resources such as personal computers, application software, data/voice/video information, host computers, and printers. Advanced Network. File Server.
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Network A communication system that enables many users to share computer resources such as personal computers, application software, data/voice/video information, host computers, and printers.
File Server File Server A computer and operating system that enables multiple access to other computers so that software applications and data files can be shared.
Host This type of computer has an operating system that allows several computers to access it at the same time. Programs and information may be processed at the host or they may be downloaded to the accessing computer for processing.
Client A computer that is used to access a file server,or another computer which allows multiple access. The client may use the accessed computer in order to process data. Other software and data may be transferred from the main computer to the client for processing.
Workstation • This is any computer that has a CPU. • The workstation may be used as a stand-alone computer for word processing, spreadsheet creation, or other software applications. • It also may be used to access another computer such as a file server.
Client/Server • Many software applications are being written based on networking capabilities. • In client/server systems, processing of data occurs at the workstation (client) and on the host or server. (Example: Exchange)
Common Network Elements • Nodes • Cabling • Data Packets • Addressing • Communication Software • Data Transmission Rate
Node • Any device or entity connected to a network is a node. • Network-connected personal computers, file servers, printers, and mainframes are individual nodes.
Cabling • This is the electrical wire used to connect equipment in order to have a network. • The cable provides a • medium for the • electrical signal that • carries information • from one networked • computer to another.
Network Interface Card (NIC) • This electrical circuit board is used by computers, printers, and other equipment so they are able to connect to a network and transfer data.
Spread Spectrum Technology (SST) • This is used by wireless networks in place of cable so that network equipment can communicate with other equipment attached to the network. Network data is transmitted by means of high frequency radio signals.
Data Packet • This is the unit of information that is sent from one network node to the next. • A computer on the network forms data into small distinct units. The data filled units are sent one-at-a-time to the receiving computer.
Transmission Rate • This is the speed at which data packets are transported on a network. • Transmission rate is affected by network topology and the medium. • On some networks the speed may be as low as 1 megabits per second (Mbps), and on others it may be over 100 Mps.
Address • Network equipment is identified by means of a unique number. • No two network computers, printers, or other network equipment will have the same number or address assigned to them. • 130.17.12.167
Protocol • An established guideline that determines how networked data are formatted into a packet, how they are transmitted, and how they are interpreted at the receiving end.
Protocols Transmission Control Protocol/Internet Protocol (TCP/IP) This is two protocols combined into one. TCP is a reliable connection-oriented data transfer method that uses connectionless routing provided by IP. Internetwork Pack Exchange (IPX) This protocol is used by Novell NetWare and provides best-effort delivery of data packets. This protocol uses a variation of the data transfer algorithm known as routing information protocol. Sequenced Packet Exchange (SPX) This protocol is packet oriented and relies on sequence numbers or acknowledgments (provided by the packet) for data transmission.
Types of Networks • Local Area Network (LAN) This is a series of interconnected computers, printers, and other computer equipment that share hardware and software resources. The service area is usually local to a given floor, office area, or building.
Types of Networks • Metropolitan Area Networks (MAN) This consists of several LANs that are connected to one another; or a network that reaches throughout a large area, such as a city or a large college campus.
Types of Networks • Wide Area Network (WAN) • A far reaching system of networks is called a WAN. • WANs can extend across states and across continents. They make it possible for thousands of users to send data to one another.
Network Capabilities • Electronic mail (e-mail) • File and print services • Host access - Remote Access Server • Client / server software • Information networks - Internet