A collision domain refers to a logical segment in a network wherein the data packets being sent by devices collide with one another. The segment consists of devices that are connected via repeaters. One common protocol where collision domains can be seen is the Ethernet protocol.
In an Ethernet environment, a collision domain is involved in the communication between nodes in the network. Hence, collision domains are often referred to as Ethernet segments.
To avoid collisions, which lessen a network’s efficiency, the domain goes through a set of procedures in managing the nodes. When a particular device in the network sends a data packet to another device in the same network, the domain forces all other devices in the network segment to pay attention to the transfer. This is done until the data packet has reached its destination. Only one device may send data at a time.
This set of procedures, however, does not fully prevent collisions. There may be certain instances where two devices attempt to simultaneously send data to the same destination. When this happens, the domain may not be able to prevent the two data packets from colliding. The target node will then stop the transmission and give a jam signal informing the other nodes that a collision took place. The two devices will subsequently yield and send their data at another time.
Collision domains are associated with a number of devices, such as switches and routers. These pieces of hardware enable two or more collision domains to communicate with one another.