The new Fibre Channel over Ethernet (FCoE) protocol standard has the goal of allowing an evolutionary approach to 10 Gigabit Ethernet (10 GbE)-based I/O consolidation in the data center by preserving all Fibre Channel (FC) SAN constructs – maintaining the latency, security, and traffic management attributes of FC, while preserving investments in FC tools, training, and SAN infrastructure. FCoE enables the transport of FC storage traffic over a new lossless Ethernet medium, Data Center Bridging (DCB). FCoE runs over Ethernet and does not utilize TCP/IP; thus avoiding the 'best effort' network delivery and server CPU processing (especially at 10 Gbps or higher data rates) limitations of the TCP/IP protocol stack.

More Here