what are network topologies with structure?

WHAT ARE NETWORK TOPOLOGIES WITH STRUCTURE?

The topology of a network is the structure defined by the interconnection scheme. This structure can be viewed as a graph with vertices representing the switching nodes and the branches representing the transmission channels. 

The choice of topology involves many interrelated factors:

1. Expected traffic
2. Routing method
3. channel capacity
4. cost

The various topologies are:

1. Mesh
2. Ring
3. Bus
4. Tree
5. Star

 Mesh Topology

In this type of structure each node is directly connected to every other node. Each device has a point to  point link with each other device. This topology provides alternative routes between nodes. A very large wire length is required and cost may become too high to be justified. 

Mesh topology

Public and private data communication networks use this kind of topologies. It is also known as fully connected topology.

Ring topology

In this topology , the host computer and workstation are connected in series forming a complete ring, for data communication . The links are unidirectional (clockwise/anticlockwise). 

Ring topology

It is economical and no collision of data takes place between two workstations. Problem arises while adding new devices in the networking series. It is used in LANs.

BUS topology

In this kind of structure, there is no central host computer. There is a single data cable which is shared by the workstations . It allows flexible networking as devices can be easily attached. It is economical , because single cable is involved possibility of data collision occurs.

Bus topology

Tree Topology

It is also known as hierarchical or vertical network. There may be more than one central nodes as it follow tree like architecture.

 It one center fails, the network can continue to be partially operational . This kind of structure is used in Remote access networks.

Tree topology

Star Topology

In this, different workstations are connected by cables with the centrally located host computer known as server or HUB. 

Star topology

The server is responsible for routing traffic and fault isolation. The failure of workstation does not effect structure but failure of centrally located host computer, HUB causes  complete  breakdown of communication network.