Data Communication

02. Compare and contrast between the bus and star topology.

 A network architecture in which a set of clients are connected by a shared communications line, called as a bus.
 A network consists of one central switch, hub or computer which acts as a conduit to transmit messages, called as a star.
 Bus networks are the simplest way to connect multiple clients, but often have problems when two clients want to transmit at the same time on the same bus.
 The star topology is a computer network connected via cables to a central system called a hub or switch there are no direct connections between any of the computers, although multiple hubs or switches can be added to increase the number of computers that may be connected to the network.
 A bus topology is the minimum complex network configuration it creates use of a single transmission medium called a coaxial cable.
 The star topology consists of shielded twisted pair wire (STP) or unshielded twisted pair wires (UTP). Due to the high cost of STP wire, most networks use UTP, however, STP wire must be used if the distance between the hub and the node beat 110m.
 In most examples the cable is many different lengths joined by a T-connector which allows the cable to divide into various directions enabling other computers to be connected to the network.
 Subsequently each computer is connected to the hub by a single cable more cable is used in a star topology than a bus topology network. The hub also adds an additional charge. Regardless of the higher cost of the additional wiring and hub the star topology is becoming more popular in current networks.
 Specific hardware is then needed to terminate the coaxial cable ends so that signals traveling to the end of the bus will not return as repeat data transmissions.
 Mostly use coaxial cables to data transmitted between switches and computers. Switches are known who the destinations of its incoming packets are. Therefore not busy as the bus topology.
 The bus topology uses the smallest amount of wire and hardware making it fairly inexpensive and permits for a relatively trouble-free installation.
 The star topology uses the biggest than the bus topology expanse of wires and hardware’s making it expensive than the bus topology.
 One simply connects the cable and T-connector from one computer to the next and then terminates the cable at both ends.
 The star topology is a computer network connected by cables to a central system called a hub or switch.
 There exist several limitations with a bus topology. There is a limit to the number of computers that can be connected by a bus topology the strength of the signal weakens as it travels along the cable, so if more computers need to be added to a network using a bus topology, a repeater will be needed at fixed intervals to strengthen the signal.
 There existing excess un-limit ports with star topology. In mostly hubs have only four ports. But also switches have between or more than 8 to 64 ports. There is a un-limit to the number of computers that can be connected by a star topology by using above mentioned switches.
 A primary problem with the bus topology is that were the cable to break at any point along the bus, the computers on whichever side of the break will lose their termination, causing the signals to repeat and corrupt data.
 A significant advantage to using a star topology is a breakdown in communication between the hub and any one computer does not have any effect on other computers in the network.
 Bus topology is works best with limited number of nodes.
 Star topology has good performance.
 Proper termination is required for bus topology. (Loop must be in closed path).
 Scalable, Easy to set up and to expand in star topology.
 If there is a problem with the cable, the entire network goes down in bus topology.
 Easy to detect faults in star topology.
 If many computers are attached in bus topology, the amount of data flowing causes the network to slow down.
 Data Packets are sent quickly in star topology as they do not have to travel through any unnecessary nodes.
 Bus topology inevitable used for single line control.
 But star topology mostly used for centralized control.
 Bus topology is cheaper than other topologies.
 But star topology is expensive to install.
 Requires less cable length than a star topology for bus topology.
 Extra hardware required for star topology.