Ethernet LAN Access Method: CSMA/CD

CSMA/CD stands for Carrier Sense Multiple Access with Collision Detection. It is the access method used in Ethernet LAN.

Carrier Sense: Before transmitting data, a device checks if the network is busy or not. If the network is busy, the device waits for some time and checks again. If the network is free, the device starts transmitting data.

Multiple Access: In Ethernet, multiple devices share the same communication medium. Therefore, multiple devices can transmit data at the same time.

Collision Detection: In case two devices transmit data at the same time, a collision occurs. When a collision is detected, the transmitting devices stop transmitting and wait for some time before re-transmitting.

Advantages of CSMA/CD:

- Efficient use of the network: With CSMA/CD, multiple devices can share the same communication medium and transmit data at the same time. This increases the efficiency of the network.
- Automatic error correction: When a collision occurs, the transmitting devices automatically stop transmitting and re-transmit after some time. This helps in avoiding data loss and errors.

Disadvantages of CSMA/CD:

- Limited distance: The length of the cable used in Ethernet LAN is limited. Therefore, the distance between devices in the network is also limited.
- Limited speed: The speed of data transmission in Ethernet is limited. Therefore, it may not be suitable for high-speed data transfer applications.

Conclusion:

CSMA/CD is the access method used in Ethernet LAN. It is an efficient method that allows multiple devices to share the same communication medium and transmit data at the same time. However, it has limitations in terms of distance and speed.