Carrier Sense (CS) • Computers have the ability to ‘listen’ to a shared communications channel and only transmit when it is free.
Multiple Access (MA) • This means that many computers can use the same channel without every message smashing into the next.
Collision Detection (CD) • If two messages do collide, the computers ‘hear’ this and back off a random period of time before re-transmitting
CSMA/CD • Collisions are natural on a Bus Topology. • However, if there are too many computers on the network, the number of collisions will go up and the network performance will slow down dramatically.