The most common LAN architecture is Ethernet. Ethernet is used to transport data between devices on a network. These devices include computers, printers, and file servers. All nodes on a shared Ethernet media transmit and receive data using a data frame broadcast method. The performance of a shared medium Ethernet/802.3 LAN can be negatively affected by several factors:

• The data frame delivery of Ethernet/802.3 LANs is of a broadcast nature.
• The carrier sense multiple access/collision detect (CSMA/CD) method allows only one station to transmit at a time.
• Multimedia applications with higher bandwidth demand such as video and the Internet, coupled with the broadcast nature of Ethernet, can create network congestion.
• Normal latency occurs as the frames travel across the Layer 1 medium and through Layer 1, Layer 2, and Layer 3 networking devices.
• Extending the distances and increasing latency of the Ethernet/802.3 LANs by using Layer 1 repeaters.

Ethernet using CSMA/CD and a shared medium can support data transmission rates of up to 100 Mbps. CSMA/CD is an access method that allows only one station to transmit at a time. The goal of Ethernet is to provide a best-effort delivery service and allow all devices on the shared medium to transmit on an equal basis. A certain number of collisions are expected in the design of Ethernet and CSMA/CD. Therefore, collisions can become a major problem in a CSMA/CD network.