What does Converged Enhanced Ethernet (CEE) add to legacy Ethernet to allow it to carry block- based storage traffic?

TCP offload is a NIC-level performance optimization that moves TCP processing to hardware, but it does not make Ethernet lossless or enable it to carry block storage traffic natively.

CEE adds lossless behavior to standard Ethernet through mechanisms like Priority Flow Control (PFC), which prevents frame drops by pausing traffic at the link level - this is essential for block-based storage protocols like FCoE and iSCSI that require reliable, in-order delivery without relying on upper-layer retransmission.

Jumbo frames increase the maximum transmission unit size for efficiency but do not address the lossless requirement; standard Ethernet can drop jumbo frames just as it drops regular frames under congestion.

Data retransmission is a recovery mechanism used by protocols like TCP after loss has already occurred, whereas CEE prevents loss in the first place, making retransmission unnecessary for storage traffic.