Definition

A collision domain is a network segment where data packets can collide with each other when multiple devices transmit at the same time. This can happen when multiple devices share the same communication channel, such as a hub-based network. In a collision domain, if two devices transmit at the same time, their packets will collide and both devices will have to retransmit their packets. This can lead to poor network performance, increased collisions, delays in data transmission and increased network congestion.

Example

Consider a small office network that has a hub as the central connection point for all devices. All the devices in the office, such as computers, printers, and servers, are connected to the hub with Ethernet cables. Because all the devices share the same hub, they are all in the same collision domain.

Resolution

To resolve this issue, a switch can be used to create multiple collision domains within a network. A switch works by creating a separate collision domain for each device connected to it. This means that each device connected to a switch has its own dedicated connection and cannot collide with other devices.

Types of Collision Domain

Shared Collision Domain

A shared collision domain is a network segment where multiple devices share the same communication channel, such as a hub-based network.

In this type of collision domain, all the devices share the same bandwidth and when two devices transmit at the same time, their packets will collide and both devices will have to retransmit their packets. This can lead to poor network performance and increased collisions.

Dedicated Collision Domain

A dedicated collision domain is a network segment where each device has its own dedicated communication channel, such as a switch-based network.

In this type of collision domain, each device is assigned its own bandwidth and when two devices transmit at the same time, their packets will not collide because they are on different channels. This leads to better network performance and fewer collisions.

Dedicated collision domains are more common in modern networks as they are more efficient, and can be created using VLANs (Virtual Local Area Networks) and other technologies.