CSMA/CD Operation

CSMA/CD Operation

Ethernet operates using CSMA/CD. By definition, CSMA/CD is half-duplex communication. Half duplex implies that only one device on the Ethernet LAN "talks" at a time, and devices connected to the same Ethernet network are considered to be part of the same collision domain. Devices sending traffic in the same collision domain have the potential of their packets colliding with each other when two devices attempt to transmit at the same time. The logical definition of this range of devices is called a domain, hence the term collision domain.

The old style telephone party line example best illustrates the concept of a collision domain, as shown in Figure 1-3.

Table 1-2 lists each party line operation and compares it to Ethernet