lossless Ethernet

Ethernet is not conceptually predestined to transmit data without packet loss. This is due to the fact that Ethernet can drop data packets in the event of overload and buffer overflow. In true lossless data transmission, all data packets must reach the receiving station without any dropout. This is important in backups, grid computing and cloud computing, server-to-server communications, and various other data center applications.

To enable Ethernet to be used in these application areas, IEEE has addressed the issue of Lossless Ethernet in its 802.1working group. The 802.1Q (bb) working group specifies a corresponding pause-based method with Priority Flow Control( PFC). The PFC protocol can simultaneously create eight separate logical links over the same physical link. Using a pause mechanism specified by priorities, each individual traffic pattern can be temporarily paused while the others continue to be transmitted. This technique transmits completely lossless without dropouts.

Lossless Ethernet is used in Fibre Channel over Ethernet( FCoE) as a low-cost alternative to Fibre Channel and in Data Center Ethernet( DCE).