Physical Topologies

Physical Topology or Network Topology is the Geographical Representation of Linking devices. Following are the four types of physical topology-

1. Mesh Topology: In a mesh topology, each and every device should have a dedicated point-to-point connection with each and every other device in the network. Here there is more security of data because there is a dedicated point-to-point connection between two devices. Mesh Topology is difficult to install because it is more complex.
2. Star Topology: In star topology, the device should have a dedicated point-to-point connection with a central controller or hub. Star Topology is easy to install and reconnect as compared to Mesh Topology. Star Topology doesn’t have Fault Tolerance Technique.
3. Bus Topology: In a bus topology, multiple devices are connected through a single cable that is known as backbone cable with the help of tap and drop lines. It is less costly as compared to Mesh Topology and Star Topology. Re-connection and Re-installation are difficult.
4. Ring Topology: In a ring topology, each device is connected with repeaters in a circle-like ring that’s why it is called Ring Topology. In Ring Topology, a device can send the data only when it has a token, without a token no device can send the data, and a token is placed by Monitor in Ring Topology.

The physical Layer is the bottom-most layer in the Open System Interconnection (OSI) Model which is a physical and electrical representation of the system. It consists of various network components such as power plugs, connectors, receivers, cable types, etc. The physical layer sends data bits from one device(s) (like a computer) to another device(s). The physical Layer defines the types of encoding (that is how the 0’s and 1’s are encoded in a signal). The physical Layer is responsible for the communication of the unstructured raw data streams over a physical medium.