Topic 1-Chapter 6: Network Topologies
             Explain the difference between logical and physical topologies. Describe the three different types of topologies.
             Answer: Topology is the basic geometric layout of the network, which shows the different way in which computers are interconnected with each other within the network. So there is a significant difference between logical and physical topology. A logical topology is a conceptual explanation of network activities whereas physical topologies show the physical installation of a network. So logical topology is much like a logical data flow diagram (DFD) and physical topology is like physical DFD.
             The topology shows the ways a network weaves connect different PC's within a network. It concerned about both the physical and logical way network nods are connected to each other. The physical topology describes how the cables are run through the network and the way in which nodes are physically connected to the network line. It is the network layout, which users can see and must actually plug together. On the other hand, logical topology describes how signals flow between different nods and how they interrelate with each other. So logically a network might be described as one way but physically it may be characterized is entirely different way (Rosch, 1988). For example An Ethernet's logical topology is a bus topology but its physical topology is a star topology. (Fizgerald & Dennis, 2002)
             There are different types of network topologies are used in telecommunications networks, among them three are widely used in WAN's and LAN's. They are as follows-
             A bus topology: A bus topology network is the simplest topology in a network in which local processors share the same communication channel. (O'Brien, 2001)
             A star topology: A network that ties all end users computers to a central computer is called a star topology. Here all computers are directly connected to the ce...