What is Network Topology ?
Network Topology is the arrangement of computers and cable links in a LAN(local area network).
Network Topology types:-
(I) Point-to-point topology: it is usually a part of a WAN(wide area network) and direct connection between two computers.
(II) Bus Network Topology: A bus network is a network topology in which computers are connected through a shared communications line called a bus. Example- motherboard.
(III) Star Topology: Star networks are one of the most common computer network topologies in which each computer is directly connected to the centralized hub or a switch. In this way , when computer 'A' sends a data packet for computer B , C and D the data flows through the switch to which both computers A,B,C and D are connected.
(IV) Token ring or Ring Topology: it is similar to star topology the only difference here is that it creates ring that permits transfer of data from one computer to another computer in a ring or circle. a taken network will pass information based on token system.
(V) Tree Topology: it is combination of characteristics of linear bus and star topologies. It is consists of groups of stars configured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of an existing network with ease.
(VI)Mesh Topology: it is fully connected or complete topology in which there is direct link between all pairs of nodes, every node connected to every other node fast reliable no hub or switch or bus to fail if one device goes down, it is only nodes affected expensive every node must be wired to every other node difficult to add nodes,there at least two nodes with two or more paths between them.
Advantages and Disadvantages of Topology:-
Bus Topology:advantage- available in low cost, good for local area network. disadvantage- have low security, efficiency becomes low when more devices connected.
Star Topology: advantage- due to isolation prevents failure of central network, The central device can handle very high utilization by only one that is central device without affecting other device. disadvantage- high cost, limited capacity of nodes, dependency on central device if central device fails then whole network affected.
Ring Topology:-advantage- to manage connectivity between computers does not requires central nodes, easily finds faults due to point-to-point linked configuration, depends on order or sequence of network every device has opportunity to transmit network. disadvantage-delay in communication, any device changes affects whole network, difficult to troubleshoot.
Tree Topology:-advantage- supported by many hardware and software companies. disadvantage- if one cable segments breakdown then entire network affected.
Mesh Topology:-advantage- it is not affected by if single device failed, high traffic due to interconnection of all devices. disadvantage- highly expensive, high maintenance necessary.