NETWORKING CONCEPTS Network A network is basically an interconnection of various points to make a connected system e.g Road, Telephone, Social Data Network A computer network therefore refers to an interconnection of computers and other peripherals by use of a communication link Peer to Peer Networks In a peer-to-peer network, all computers are considered equal; they all have the same abilities to use the resources available on the network. Peer-to-peer networks are designed primarily for small to medium local area networks. Strength (Setup Cost is low, simple to manage) Weaknesses (Decentralized, Low security) Client/Server Networks Client/server network operating systems allow the network to centralize functions and applications in one or more dedicated servers. Advantages (Centralized, Scalability, Flexibility, Interoperability, Accessibility) Disadvantages (Cost, maintenance, Dependence one server) Server Types A sever in a network is dedicated to perform some specific task in support of other computers on the network. One server may perform all these tasks, or a separate server may be dedicated to each task. Common server types 1. File server 2. Print server 3. Application server 4. Message server 5. Database server File Server It offers services that allow network users to share files with network .File servers , users can exchange, read, write and manage shared files and the data contained in them. They are designed specifically to support the file services for a network. The file servers include: a) File transfer b) File storage c) File update synchronization d) File archiving File Transfer Network offers file transfer services by typically transferring files between clients and servers. This calls for file security. Every network operating systems has its own level of file security. Higher level use passwords to control system access, File attributes to limit file usage and encryption schemes to prevent data from being obtained by unauthorized individuals. File Update Synchronization It involves keeping all the files up to date. It ensures that changes made to a file are organized in chronological order in which they actually took place and that files are properly updated. File synchronization is usually an added option or an upgrade in most network operating systems File Archiving This is the process of backing up files on offline storage devices such as tapes or optical disks. Print Server A print server on a network will offer the following advantages:
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• Allow user to share printers • Allow users to place the printer where convenient not just near individual computer • Achieve better performance by using high -speed network data transfer and print queues. • Allow user to share network fax services. • Cuts cost by allowing shared access to printing devices. Network operating systems offers print queues, which are special storage, are where print jobs are stored and then sent to the printer in an organized fashion. The print jobs are stored in the queue and then forwarded to the printer when the printer has finished the jobs scheduled ahead of it. At times jobs may be printed in the order of priority according top other criteria Objectives of Networking • Sharing • Backup • Communication • Security Network Components • Clients • Server • NIC • Media • Repeater • Hubs • Bridges Geographical Classification of networks • LAN • MAN • WAN Characteristics of LAN, MAN, WAN LAN (Cheap, fast, radius about 3KM) MAN (Relatively Cheap, fairly fast, radius about 10KM) WAN (Costly, Slow, No limits, not secures) Classification of Network by Processing Modes Distributed networking In a distributed networking each machine is capable of operating independently. The network is used for the easier sharing of data. Centralized Networking Centralized networks are used in mainframe configurations where the network client devices are actually dump terminals where all...