Topology can simply be defined as the geographical orientation as well as arrangement of networking components of a network. Similarly, protocol can be described as the set of rules and procedures which govern the transmission of messages over a physical networking medium.
Here, in this post, we’re going to describe about Bus Topology, which is a major type of topology in networking. Before knowing about Bus Topology, let us first know about Ethernet Topology.
Ethernet Topology was developed at the University of Hawaii so as to connect the computers on the various islands of Hawaii. It was a radio-based design. The term ‘Ethernet’ is a compound word of ether which means air and net which means network. Later, Robert Metacafe went to Xerox’s Palo Alto Research Center (PARC) laboratories. The radio portion was eliminated and changed to coaxial cabling. This was string from station to station. This station to station topology was named linear bus.
Ethernet uses bus topology. This is the simplest and widely used network topologies. Ethernet’s bus consists of one continuous length of coaxial cabling (trunk) and a terminating resistor (terminator) at each end. The Ethernet message travels along the bus in both directions until it is picked up by a Network Interface Card (NIC) of workstation. If the message is missed or not recognized, it reaches the cabling and dissipates at the terminator. If it weren’t for the terminator, the message would reflect back towards the trunk and cause harmful collisions.
All workstations have equal access to the trunk. The number of nodes and length of the trunk can be expanded easily with repeaters.
If a break occurs in the cabling or if too many nodes try to access the trunk simultaneously, the whole topology crashes. In general, the bus topology is flexible and inexpensive which makes it ideal for Ethernet LANs.
The major advantages of Ethernet are:
- It is a cheap way to achieve high-speed Local Area Network transmissions, i.e. 10 to 100 MBPS.
- IT is the technology which supports various writing configurations.
- It works well with a large number of Local Area Networks and micro-to-mainframe applications.
- Its installation is quite easier.
The disadvantages of Ethernet are:
- Ethernet is not a high-level performer in high-load environments. This protocol (CSMA/CD: Carrier Sense Multiple Access/Collision Detection) can slow down dramatically if hundreds of workstations are competing for the same cabling trunk.
- Its linear bus cabling system can sometimes make it difficult to isolate problems.