Post on 03-Jan-2016
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LAN (Local Area Network)◦A group of computers and
associated devices (printers, etc.) ◦ connected through a wired or
wireless medium◦ by networking devices (hubs,
switches, routers)◦ administered by a single
organization.◦Use protocol for communication
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Two types of physical connections: Dedicated or Point-to-point◦Direct connection between two computers
Shared◦Multiple computers share the media
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Advantages Each network connection is
independent and so can be customised to suit the type of data which it will transport.
Disadvantages There are many more
connections than there are computers.In practice, point to point is seldom used between more than 2 computers.
Computer A
Point to Point network
Black links show four connections from computer A to all computers in the network
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Most local area network (LAN) technologies use shared access to medium for computers connected to the LAN.
Topology is the term used to classify a network into a category depending on how it laid out.
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Some of the popular network topologies are:◦Star Topology Distributed Star◦Bus Topology◦Ring Topology◦Tree Topology◦ Mesh Full Mesh Partial Mesh
Physical bus topology consists of a trunk (main) cable with only two end points.
Advantage ◦ cost: no hubs are required,
and shorter lengths of cable can be used. It is also easy to expand
Disadvantages : ??
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Individual computers are connected to a central point, called a hub.
Max distance between nodes and hub IS 100 m when UTP cable is used
Advantages The failure of a single
computer will not affect the rest of the network
Disadvantages Hub failure can bring down
the network Network prone to bottlenecks
More complex form of the physical star topology, with multiple central connection points connected to form a string of stars.
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Computers are connected to each other to form a closed loop.
Advantages The data carrying capacity of
the network is shared by all users
Disadvantages Adding and removing
computers disrupts the network. computer
cable
Also called a "hierarchical" or "star of stars" topology
Nodes are connected in groups of star-configured workstations that branch out from a single "root,"
The root node usually controls the network and sometimes network traffic flow.
This topology is easy to extend: when new users need to be added
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Full mesh topology◦ each node is physically
connected to every other node Full mesh is generally
utilized as a backbone where there are few nodes but a great need for fault tolerance
Advantage ◦ Highly fault tolerant: when one
node fails, traffic can easily be diverted to other nodes
Disadvantages: ?Partial Mesh
Full Mesh
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At the center of any cellular technology is the cellular transceiver, an omni-directional antenna whose range projects a circular "footprint." This footprint is the "cell" that gives cellular technology its name
As the cellular user moves from one cell to another, the user's signal is transferred from one antenna to another
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Click on VM Workstation symbol on your desktop Start a virtual machine as follows:
Group 1 (Tues. 9-11) : 1017-01 Group 2 (Tues. 11-1) : 1017-02 Group 3 (Wed. 11.30-1.30) : 1017-03
Username and password are same e.g.: username:1017-01, password:1017-01
Use CTRL-alt keys to toggle between main machine and virtual machine.
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You have complete admin rights on VM Please use the same PC for next few weeks All tasks will be performed on this virtual machines When installing a software on VM, ◦ PLEASE DO NOT USE C:\ drive, ◦click browse button to select E:\ drive
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Set up a network using following Topologies◦ Star◦Distributed Star◦ Point-to-point ◦ Tree
Refer to your task sheet for details
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