Folsom Lake Center
Carrier Sense Multiple Access with Collision Detection is a contention based networking protocol, and it works at the Media Access sub layer of the OSI reference model. It is a contention based media access method because any machine can transmit when it needs to if no other machine is in transmission. The contention occurs during the time it takes to transmit and receive a frame. Because there is a time lapse between the transmission and reception of a frame, another machine can transmit a frame in this same duration. The contention time is the window for collisions to occur.