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2  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

RD-CSY10173 Two types of physical connections:  Dedicated or Point-to-point ◦ Direct connection between two computers  Shared ◦ Multiple computers share the media

RD-CSY10174 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

RD-CSY10175  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.

RD-CSY10176  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 : ?? 7RD-CSY1017

8  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. 9RD-CSY1017

10  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 11RD-CSY1017

 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 12RD-CSY1017

 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 13RD-CSY1017

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 Click on VM Workstation symbol on your desktop Start a virtual machine as follows: Group 1 (Tues. 9-11) : Group 2 (Tues. 11-1) : Group 3 (Wed ) : Username and password are same e.g.: username: , password: Use CTRL-alt keys to toggle between main machine and virtual machine. RD-CSY101715

 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 RD-CSY101716

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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 18RD-CSY1017

 All sections on the sheet should be completed, including observation and reflection, before posting it on your blog. RD-CSY101719