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6.3.1 Mesh Topology

            A mesh topology is a network design where each device or node is directly connected to every other device or node in
            the network. This provides multiple redundant paths for data transmission, ensuring high reliability and fault tolerance.
            Here is a simple diagram illustrating a mesh network (Figure 6.5):

























                                                      Figure 6.5 Mesh Topology
            In Figure 6.5, the lines between the nodes represent the physical connections. This fully connected mesh network
            allows for direct communication between any pair of nodes without relying on a central device or server. A dedicated
            point-to-point link connects every device to every other device. In a mesh topology, we need n(n-1)/2 duplex-mode
            links. Every device must have (n-1) I/O ports to be connected to other n-1 stations.

            Advantages of Mesh Topology
            1.  Multiple paths ensure network reliability even if one link or node fails.

            2.  New nodes can be easily added without disrupting the existing network.
            3.  Parallel transmission across multiple paths enhances data transfer speed.
            4.  No central point of failure makes it difficult for unauthorized access.

            Disadvantages of Mesh Topology

            1.  Requires a significant number of physical connections and network devices.
            2.  Managing and troubleshooting individual links or nodes can be complex.
            3.  Diagnosing and repairing faults or failures can be time-consuming.

            6.3.2 Bus Topology
            In bus topology, various nodes are connected to a long cable, called backbone cable.  The nodes are connected to the
            backbone cable via connectors, also called taps. In Figure 6.6, we show a network that uses bus topology. Messages in a
            bus topology  are broadcast to all nodes. So, the network is called a broadcasting network. Although every node receives
            the message broadcast by a node, a node knows whether it is the intended recipient by examining the message’s
            destination address.  When one device communicates a message, other devices wait for the transmission to complete.



                                                                Tap             Cable
                                              Tap      Tap               Tap


                                                      Figure 6.6 Bus Topology

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