Topology is the geometric arrangement of a computer system in the network. Common topologies include a
- Linear bus Topology
- Star Topology
- Tree Topology and
- Ring Topology
Linear Bus
A linear bus topology consists of a central cable with a terminator at each end. All nodes (file server, workstations, and peripherals) are connected to the linear cable.
Advantages of a Linear Bus Topology
- Easy to connect a computer or peripheral to a linear bus.
- It requires less cable length than a star topology.
Disadvantages of a Linear Bus Topology
- The entire network shuts down if there is a break in the main cable.
- Terminators are required at both ends of the backbone cable.
- Difficult to identify the problem if the entire network shuts down.
- Not meant to be used as a stand-alone solution in a large building.
Star Topology
A star topology is designed with each node (file server, workstations, and peripherals) connected directly to a central network hub, switch. Data on a star network passes through the hub, switch, before continuing to its destination. The hub, switch, manages and controls all functions of the network. It also acts as a repeater for the data flow.
Advantages of a Star Topology.
- Easy to install and wire.
- No disruptions to the network when connecting or removing devices.
- Easy to detect faults and to remove parts.
Disadvantages of a Star Topology
- Requires more cable length than a linear topology.
- If the hub, switch fails, nodes attached are disabled.
- More expensive than linear bus topologies because of the cost of the hubs, etc.
Tree topology
A tree topology combines characteristics of linear bus and star topologies. It consists of groups of star configured workstations connected to a linear bus backbone cable. Tree topologies allow for the expansion of an existing network.
Advantages of a Tree Topology
- Point-to-point wiring for individual segments.
- Supported by several hardware and software venders.
Disadvantages of a Tree Topology
- Overall length of each segment is limited by the type of cabling used,
- If the backbone line breaks, the entire segment goes down.
- More difficult to configure and wire than other topologies.
Ring Topology
In-ring network each node connects to exactly two other nodes, forming a single continuous pathway for signals through each node - a ring. Data travels from node to node, with each node along the way handling every packet.
Advantages
- Very orderly network where every device has access to the token and the opportunity to transmit
- Performs better than a star topology under heavy network load
- Does not require a network server to manage the connectivity between the computers
Disadvantages
- One malfunctioning workstation or bad port in the MAU can create problems for the entire network
- Moves, adds and changes of devices can affect the network
- Much slower than an Ethernet network under normal load.