Network topologies

Network topology

A network topology is the layout of the interconnections of the nodes of a computer network. Common layouts are:

 Bus network:

 all nodes are connected to a common medium along this medium. This was the layout used in the original Ethernet, called 10BASE5 and 10BASE2.

 Star network:

 all nodes are connected to a special central node. This is the typical layout found in in a Wireless LAN, where each wireless client connects to the central Wireless access point.

 Ring network: 

each node is connected to its left and right neighbor node, such that all nodes are connected and that each node can reach each other node by traversing nodes left- or rightwards. The Fiber Distributed Data Interface (FDDI) made use of such a topology.

 Mesh network:

 each node is connected to an arbitrary number of neighbors in such a way that there is at least one traversal from any node to any other.

A fully connected network: each node is connected to every other node in the network.

Note that the physical layout of the nodes in a network may not necessarily reflect the network topology. As an example, with FDDI, the network topology is a ring (actually two counter-rotating rings), but the physical topology is a star, because all neighboring connections are routed via a central physical location.