Network Topology Network topology is the physical arrangement of computers in a network. Common network topologies include the bus, ring and star . nodes nodes nodes
I) Bus Topology A bus network consists of a single central cable, to which all computers and other devices connect. The bus physical cable that connects the computer and other devices. The bus in a bus network transmits data, instruction and information in both directions. When sending device transmits data, the address of the receiving device is included with the transmission so the data is routed to the appropriate receiving device. Bus networks are and popular on LANs because they are inexpensive and easy to install. One advantage of the bus network is that computers and other device can be attached and detached at any point on the bus without disturbing the rest of the computer.
If one node fail, the busnetwork would still function aslong as the backbone isworking
Advantages Disadvantagesa) easy to implement and extend Limited cable length andb) Cost effective as only a single number of stations cable is used n If there is a problem with thec) Cable faults are easily cable, the entire network goes identified down e Maintenance costs may be higher in the long run. n Performance degrades as additional computers are added or on heavy traffic y Proper termination is required (loop must be in closed path)
II) Ring Topology On a ring network, a cable forms a closed loop (ring) with all computers and device arranged a long the ring. Data transmitted on the ring networks travel from device to device around entire ring, in one direction. When a computer or device send data, the data travels to each computer on the ring until it reaches its destination. If computer or device on a ring network fails, all devices before the failed device are unaffected, but those after the failed device cannot function. A ring network can span a larger distance than a bus network, but it is more difficult to install. The ring topology primarily is used for LANs but also is used in WANs.
If one of the nodes fails, the network will fail to function.
Advantages Disadvantagesa) A physical ring topology has a) If any nodes goes down, the minimal cable requirement entire ring goes down.b) No wiring center or closet b) Troubleshooting is difficult needed because communication is onlyc) The message can be one way. automatically acknowledge c) There will be a limit on thed) No collision exist between distance between nodes. nodes.
III) Star Topology All of the computers device (node) on the network connect to the central device, thus forming a star. The central device that provides a common connection point for nodes on the network is called the hub. All data that transfer from one node to another passes through the hub, in both direction. Similar to a bus network, star networks are fairly easy to install and maintain. Nodes can be added to and removed from the network. In one node fails, one that node affected. If the hub fails, the entire network inoperable until the hub is repaired. A star network generally requires more cable
If one nodes fails, the star network can still function as long as the host is working. If the host fails, the network will fail to function.
Advantages Disadvantagesa) Easy to install and wire i Failure of the central hubb) No disruption to the network causes the whole network then connecting or removing failure devices It is slightly more expensivec) Easy to detect faults and to than using bus topology remove parts o Requires more cabled) More suited for larger networkse) Easy to expand networkf) Easy to troubleshoot because problem usually isolates itself
Differentiate between the three types of Network Topology TOPOLOGY BUS RING STARConfigurationCentral Device Not available Not available Hub or switchData Transmitted Both direction One direction Both directionInstallation and Easy Difficult EasyMaintenanceIf one node fails Does not effect the The entire network Does not effect the rest of nodes stop working rest of nodes