Network Topology Advantages and Disadvantages

 Network Topology Advantages and

 Disadvantages

Topology is a method in which networks are physically connected together networks. Topology determines complexity of connecti ve computers and therefore the cost of network cable installation it also determine the strategy for physically expanding the networks in future.

Different topologies are as follows-

BusTopology 

In Bus Topology computers are connected by a single length cable with a terminator at each end. It is very simple and most widely used for Lan Computing. It is passive topology that means only one computer can send message at a time. So, the numbers of ocmputers connected in a bus affects the speed of the network. A computer must wait until the bus is free before it can transmit each node is connected to two others except the machine at either end of the cable which are connected only two one other node (Linear Topology)

Advantages of Bus Topology

• The Bus Topology is simple reliable easty to use and understand small sized Lan's.

• Bus requires or needs least amount of cable to connect the computers. Therefore, it is less  expensive than other cabling arrangements.

• It is easy to extend a bus. Two cables can be joined into one longer cable with a connector. It allows computers to join the computer network.

 Disadvantages of Bus Topology

• Heavy network traffic can slow down a bus considerably. This is because any computer can transmit any time.

• A bus network with many computer can spend a lot of Bandwidth with the computers interuppting each other instead of communicating.

• Trouble shooting  a bus is difficult cable can break from any where that cause communication fault.

• Cable break or loose connectors causes the whole network down.

 Ring Topology

This layout is similar to the linear bus bus except that the nodes are connected in a circle using cable segment. In this layout each node is physically connected only to two other nodes.

Each node passes information passage along to the next until it arrives intendent destination. Since each compute retransmit wht it receive.  There is no termination because there is no end after ring. Performance of on this topology is faster  because each portion of the cabling system is handling only data floor between two machine.

It can  be found of P2P networkwhere each machine manages both information processing and distribution of the file. It is known as Circular topology.

 Advantages of Ring Topology

• Because every computer is given equal access to the token no noone computer can monopolies the network.

• The fair sharing of the network allows the network to Degrade gracefully. It continues the function in a slower manner to fail completely.

 Disadvantages of Ring Topology

• Failure of one computer on the ring affects the whole network.

• It is difficult to trouble shoot.

• Adding or removing computers disrupts the network.

 Star Topology

Each computer on a star network communicates with a central hub that recents the message either to all the computers or all only to destination computer. The hub in a broadcast star network can be active or passive. Star is a example of centralize topology  where a central computer (server) is responsible for the whole network . Nodes request to server for communication. It is known as Centralize Topology.

 Advantages of Star Topology

• It is much easier to modify or add new computers to a star network.

• Single computers failures do not necessarily bring down the whole star network.

• The hub can detect the network fault on isolate offending computer or network cable and allow rest of network to continue its operations.

• You can use several cable type in the same network with the hub that can accomodate multiple cable types.

 Disadvantages of Star Topology

• If the central hub fails the whole network fails to operate.

• many star network requires a device at the central point to re-broadcast  or switch the network traffic.

• It is costly to manage star network.

Mesh Topology (Pully connected)

It is a fully connected topology in this all devices are connected with many redudant interconnection between network nodes.

In a well connected topology, every node has a connection to every other node in the network. The cable requires are high. Failure in one of the computer does not cause the network breakdown , as they have alternative parts to othe computer. No of connected input and output devices.

Advantages of Mesh Topology

• Use of dedicated links eleminates traffic problems.

• Failure in one of the computer doesn't affect the entire network.

• Point to point link makes fault isolation easy.

• It's robust.

• Privacy between computers is maintained as message travel along dedicated path.

Disadvantages of Mesh Topology

• The amount of cabling required is high.

• A large number of Input/Output ports are required.

Tree Topology (Hairarchy Topology)

Tree topology is a LAN topology in which only one root exit between two any node on the computer. The pattern of connections resembles a tree in which all branches spring from root. Tree topology is a Hybrid Topology . It is similar to the star topology but nodes are connected to the secondary hub which in term each to the central hub. In this topology all groups are star configured network are connected  to linear bus backbone.

Advantages of Tree Topology

• More than one server.

• Installation and configuration are easy.

• Fault can be detected or teased easily.

• The addition of secondary hub allows more devices to be attached to central hub.

• Support multitypes cable such as – STP, UTP, ordinary telephone cable etc.

 Disadvantages of Tree Topology

• More cable require.

• Failure in the root hub brings to entire network to the hard.

 Difference between Tree and Star Topology

Tree Topology	Star Topology
All devices are not connected to the central hub directly.	All devices are connected to the central hub.
More than one central hub are possible.	There is only one central hub.
The addition of secondary hub allows more devices to be attach the central hub.	In orders for the nodes to communicate hub allows more devices to be across the network data always passes through the central hub.
Less cabling is required in compared to star topology.	More cabling is required