SECTION A: (2 Marks for each question) FILL IN ... - Peace Corps Wiki

SECTION B
(Short answer questions) 15 points each
1. What is a communication network What are the disadvantages of a network
A communication network is a group of interconnected computers that share resources
such as peripherals, disk space, processing power etc using a common set of protocols
over a shared communication medium such as Co-axial cable, Unshielded Twisted Pair
Cable (UTP) or Fibre Optic Cable, the medium could also be wireless using Satellite,
Microwave or radio frequency technologies.
The largest network in the world is based on the IP (Internet Protocol) suite and is known
as the internet.
Resources may be shared on a peer-to-peer or a client/server basis.
With the client/server model, the server has the resource and makes it available to the
clients – this is common practice for sharing disk space (file server) and printers (printer
server).
Application servers allow users to run applications on a remote machine thus making use
of the servers CPU and memory instead of that of the local machine.
Servers may be installed to provide services for local users only (INTRANET), for a
wider but specific audience such as business partners (EXTRANET) or to the whole of
the community of interconnected networks (INTERNET).
In the peer-to-peer model both participants have resources that are shared by the other on
an equal basis, thus people can copy files to each other’s disks or use messaging systems
to communicate with each other using peer-to peer software.
Napster and similar file sharing systems allow people to share music and files over a peer
to peer network.
Networks can be classified by the area that they cover: Local area networks (LANs) are
confined within a small area such as a classroom Campus Area Networks (CANs) cover
a college Campus, Metropolitan area networks (MANs)cover a town while wider areas
are serviced by Wide Area Networks (WANs).
The disadvantages of networks include:
• Cost of installation
• On-going cost of maintenance
• The need for trained experts to provide the installation and maintenance
• The need for a reliable stable electricity supply
• The need to secure data and equipment so that only authorized users can access
them.
• The danger of propagation of viruses, worms and other malware through the
network.
• Server failure, cable failure or other network component failure may prevent
access to resources upon which people have come to rely.
• As network use increases the performance may degrade unless the network is
properly designed, maintained and continually upgraded.