Page 131 - DCAP516_COMPUTER_SECURITY

Unit 10: Network Concepts

Notes
Figure 10.3: Ring Topology

Disadvantages

(i) Failure of one node brings the whole network down.
(ii) Error detection and network administration becomes difficult.
(iii) Moves, adds and changes of devices can effect the network.
(iv) It is slower than star topology under normal load.
Generally, bus architecture is preferred over the other topologies - of course, this is a very
subjective opinion and the final design depends on the requirements of the network more than
anything else. Lately, most networks are shifting towards the star topology. Ideally we would
like to design networks, which physically resemble the star topology, but behave like bus or
ring topology.

Self Assessment

State whether the following statements are true or false:
6. A topology, which is a pattern of interconnections among nodes, influences a network’s
cost and performance.

7. There are Five primary types of network topologies which refer to the physical and
logical layout of the Network cabling.
8. Bus is the simplest and the oldest and all the telephone switches are based on this.

9. Bus consists of a single cable, called a Backbone that connects all workstations on the
network using a single line.
10. The purpose of the terminators at either end of the network is to stop the signal being
reflected back.

10.8 Summary

A network consists of two or more computers that are linked in order to share resources
(such as printers and CD-ROMs), exchange files or allow electronic communications. The
computers on a network may be linked through cables, telephone lines, radio waves,
satellites or infrared light beams.

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