Collision Domain and Broadcast Domain

What is Domain?

Domain means a territory or a region. From the networking point of view, domain is a territory of all the connected devices where devices data travel on that domain.

In networking, Domain refers to any group of devices, computers, printers, servers, etc. that are connected with each other and can share their resources on the network.


What is Collision domain?

A collision domain is a network segment where data packets from multiple devices can collide with each other when they are transmitted at the same time. This can happen when multiple devices try to use the same communication medium (such as a cable or a wireless channel) to send data simultaneously.

In a collision domain, all devices share the same bandwidth and compete for the same transmission resources. If two devices try to send data at the same time, their packets will collide and become corrupted, resulting in the loss of data. This can cause network congestion, slow down data transfer, and lead to errors in communication.

Collision domains are typically found in Ethernet networks that use shared media, such as coaxial cable or hub-based Ethernet. In these networks, all devices connected to the same segment share the same bandwidth and compete for access to the communication medium. If two devices try to send data at the same time, their packets will collide and have to be retransmitted.

When collisions occur, the data packets are lost, and the devices must retransmit their data. This results in decreased network performance and slower data transfer rates.

A shared media is a medium of data transfer where two or more users can transfer data at the same medium. Ethernet hubs and BUS topology are used in shared media where data signals travel on the same medium. Both work in half-duplex mode.

bus topology collision domain 1

In this example of BUS topology, all the devices are connected with the LAN cable, which is shared with all the devices. In this network, if more than one device sends a message, then it will collide because it has a single collision domain.

As the same happens on the HUB network because all devices have the same collision domain.

How to prevent Collision Domains

  • Use switches instead of hubs: Switches create separate collision domains for each connected device, allowing devices to communicate with each other without interference from other devices on the network.
  • Implement collision detection: Collision detection mechanisms, such as Carrier Sense Multiple Access with Collision Detection (CSMA/CD), can help prevent collisions by detecting them when they occur and retransmitting data as necessary.
  • Use point-to-point connections: Point-to-point connections between devices, such as switches or routers, can prevent collisions by providing a dedicated communication path between the sender and receiver.
  • Use full-duplex communication: Full-duplex communication allows devices to send and receive data simultaneously, which reduces the possibility of collisions.


What is Broadcast domain?

A broadcast domain refers to a network area where all devices can receive broadcast messages within the same segment.

The size of a broadcast domain can have a significant impact on network performance. If a broadcast domain is too large, it can result in increased network traffic, slower data transfer rates, and decreased network performance.

To optimize network performance, network administrators can use techniques such as subnetting, which creates smaller broadcast domains by dividing a larger network segment into smaller subnetworks. This results in decreased network traffic, faster data transfer rates, and improved network performance.


You should also read: Unicast, Broadcast and Multicast


error: Content is protected !!