Network Topology is the arrangement by which computer systems are connected to each other. They can define both the physical and logical aspects of the network. Physical topology implies the physical placement of the components of the network. It’s the actual geometric layout of the workstations. Logical topology deals with how the data flows logically across different components.
Physical topology also includes the cabling layout used to link devices. There are many physical topologies in computer networks.
- Bus Network Topology: In the bus network topology, every workstation is connected to a main cable/component called bus. It can be interpreted therefore that every workstation/system is connected to every other workstation/system. Information can flow in any direction; however, there are at times master/slave architecture is involved where the information flows only in one direction.
There are two kinds of bus topologies:
- Linear bus: In linear bus topology, all the nodes of the network are connected to a common transmission medium which has two endpoints. All the data that has to be transmitted is sent over this medium.
- Distributed bus: In distributed bus topology, all the nodes of the network are connected to a common transmission medium which has more than two endpoints.
- Point-to-Point Topology: It’s probably the simplest topology with two endpoints and a direct connection between them. The essential idea of an end-to-end connection is that of an unimpeded communication. There are two kinds of point-to-point connections:
- Permanent: The end-to-end connection appears to the user as permanent.
- Switched: A point-to-point circuit can be set-up dynamically and it can be dropped when not needed. The most common example of it could be telephony.
- Star Network Topology: There’s a central workstation/computer to which all other workstations are directly connected. Now, that means that every workstation is connected to every other workstation through a central computer.
- Ring Network Topology: The workstations are connected in a closed loop formation. The adjacent pairs of nodes are directly connected. There is no open-endedness. In order for one node to communicate with any other node than the adjacent one, the information will indirectly flow from the intermediary workstations until it reaches the destination.
An important point to make here is that if token ring protocol is used in ring or star network topology then the signal flows in one direction only.
- Mesh Network Topology: It has either partial mesh or full mesh scheme. In full mesh, every system is connected to every other system directly. In partial mesh, some are connected to all the others, some are connected to only a few.
- Tree Network Topology: Basically, it employs two or more star networks connected together. The central systems are connected to a main bus. It can also be said that a tree network is a bus network of star networks.
- Hybrid Networks: Hybrid networks use a hybrid of two or more topologies such that it becomes difficult to tell which topology it is. They exhibit the combination of multiple topologies, using the required features from each topology.