In a bus topology, each network device is connected to a cable backbone. The most common cable used to create a backbone is coaxial. 10Base2 (thinnet) and 10Base5 (thicknet) are used to create the backbone function.
A bus topology requires that each network device share the same network connection, the backbone. When a packet is sent on the backbone, each of the network devices reads the packet header and determines if it is destined for itself. Each network device needs to see all the traffic on the backbone to work properly.
There are several advantages when a bus network is used. They are as follows:
Uses a limited amount of cable: A bus topology allows you to install a network with a limited amount of cable. Since each network device is connected directly tot he backbone, you do not need to add cable for a network connection.
Ease of installation: Since coaxial cable is used for bus topologies, the learning curve for understanding the installation process is small. All network devices connect to the same backbone, so ensuring the proper drops are installed is easy. This is especially true when designing and implementing a small network.
Limited cost: Coaxial cable is extremely affordable, so cable investment is limited. There is no need to install patch cables for network device connection.
There are several disadvantages when using a bus topology. The include the following:
Network device relocation: Moving a network device from one location to another can be troublesome in a bus topology. You need to ensure a drop exists in the future location and that the cabling in the current location is not left unconnected.
No fault tolerance: When one network device fails due to a cable or network interface card issue, the rest of the network suffers an outage as well. The bus topology is exposed to this issue, because each network device communicates on the same backbone.
Poor troubleshooting: A bus topology is extremely difficult to troubleshoot for errors on each network device can affect the whole network. A slight cable issue with one network printer could cause the entire network to fail.