Page 106 - DCAP104_EXPOSURE_TO_COMPUTER_DISCPLINES

Unit 5: Operations of Network

Notes
Figure 5.19: A Network Router

Internet

DSL/Cable
Modem

Network
Router

Wireless
Access
Point
Computer
equipped with
network adapter

Computer Notebook
equipped with equipped with
wireless adapter wireless
PCMCIA Card

5.4.6 Firewalls

Firewalls are the most important aspect of a network with respect to security. A firewalled
system does not need every interaction or data transfer monitored by a human, as automated
processes can be set up to assist in rejecting access requests from unsafe sources, and allowing
actions from recognized ones. The vital role firewalls play in network security grows in
parallel with the constant increase in ‘cyber’ attacks for the purpose of stealing/corrupting
data, planting viruses, etc.
5.5 Summary

• A network architecture is a blue print of the complete computer communication network,
which provides a framework and technology foundation of network.
• Network topology is the layout pattern of interconnections of the various elements (links,
nodes etc.) of a computer network.
• Protocol specifies a common set of rules and signals of computers on the network use to
communicate.
• Network media is the actual path over which an electrical signal travels as it moves from
one component to another.
• All networks are made up of basic hardware building blocks to interconnect network nodes
such as NICs, bridges, hubs, switches and routers.
5.6 Keywords

Optical fiber cable: Optical fiber cable consists of one or more filaments of glass fiber wrapped
in protective layers that carries a data by means of pulses of light.

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