Network Topologies

The term Computer Network is used when two or more computers connected together to share data files, Internet, printer, applications etc. Network can be very simple, such computers that are connected to share the resources using a hub (or switch) or they can be very complex covering large geographical areas that use multiple media and protocols.

LAN means Local Area Network, and usually limited to a specific area or location. The term   "Topology" is used to explain the broad layout of the network cables and workstations, and the location of all network components. It is also indicative of how the information or data flows within the network.

There are several Network Topologies that can be used for set LAN in our organization.

1.      Bus Topology: 

In this topology all the computers are attached to a single continuous cable, which is typically a co-axial one, and terminated at both the ends, that ensures that the signals are not reflected after reaching the end of the cable.  Using Bus Topology, the information signals are available at every individual workstation; they discard information that is not meant for them. 

Figure 1

2.      Star Topology: 

In a star topology each computer is connected to a centrally placed Hub or a Switch by a separate cable. The simplest form of the star topology consists of multiple cables one for each network device attached to a single, central connection device. Only required physical characteristic is that each network device be connected by its own cable to the central connection point.

 Figure 2

3.      Ring Topology:

In the ring topology each computer is connected directly to two other computers (one in the up-stream, and another in the down-stream) in the network. Here individual devices are connected to a central hub, just as they are in a star or distributed star network. However, within each hub the physical connections form a ring. Each open end is connected to an open end of some other hub (each to a different hub), so that the entire network cable forms one physical ring.

 

Figure 3

4.      Mesh Topology:

In Mesh topology, a path exists from each node to one or more nodes in the network. In a Full Mesh, every node will have a connection to every other node in the network. Partial mesh topology uses fewer connections, and though less expensive is also less fault-tolerant. Partial and hybrid meshes are usually found in peripheral networks connected to a full-mesh backbone

Figure 4