congestion notification (802.1Qau) (CN)

Congestion Notification (CN) is one of the protocols developed by the IEEE802.1working group for Data Center Bridging( DCB), others are Priority Flow Control( PFC), Enhanced Transmission Selection( ETS) and Data Center Bridging Exchange ( DCBX).

Congestion Notification is about congestion control for end-to-enddata centerconnections. And it is for those protocols that do not have a built-in mechanism for congestion control such as Fibre Channel over Ethernet( FCoE). The CN protocol takes into account appropriate indications of traffic congestion.

In Data Center Bridging (DCB), the Quantized Congestion Notification( QCN) described in IEEE 802.1Qau is used, which offers significant advantages in lossless transmission.