Which of the following is not a controlled access method of media access control?
A)Token passing
B)CSMA/CD
C)polling
D)roll call polling
E)hub polling

Question

Quizplus · Accepted Answer

CSMA/CD (Carrier Sense Multiple Access with Collision Detection) is not a controlled access method but is instead a contention-based access method. In CSMA/CD, every node listens to the network media before transmitting data. If no other node is transmitting, the node can send data. If a node senses some carrier signal, it waits for some time before trying to send the data again. This delay helps to avoid collisions.

Token passing, polling, roll call polling, and hub polling are all examples of controlled access methods. In token passing, a token is passed among a group of nodes, and only the node with the current token can transmit data. In polling, a central node asks each node in turn if it has data to send. In roll call polling, each node's turn is predetermined, so that the central node knows in advance which node will respond. In hub polling, the hub controls access to the network by instructing each node when it can transmit data.

Which of the Following Is Not a Controlled Access Method