Which method is a TCP/IP-based protocol for establishing and managing connections between IP- based storage devices, hosts, and clients?

FCIP tunnels existing Fibre Channel frames over an IP WAN but is not a TCP/IP-native storage protocol - it requires an underlying Fibre Channel infrastructure and does not natively manage IP-based storage device connections.

iFCP is a gateway-to-gateway protocol for interconnecting Fibre Channel SAN islands over IP, not a general-purpose TCP/IP protocol for managing connections between IP-based storage devices and clients.

iSCSI (Internet Small Computer Systems Interface) is a TCP/IP-based protocol that carries SCSI commands over standard IP networks, establishing and managing connections between storage devices, hosts, and clients natively on the IP stack. It requires no dedicated Fibre Channel hardware, making it the direct answer for a protocol that is both TCP/IP-based and purpose-built for IP storage connectivity. iSCSI initiators and targets communicate using standard TCP sessions over port 3260.

FCoE encapsulates Fibre Channel frames over Ethernet and does not use TCP/IP as its transport layer, relying instead on lossless Ethernet via Data Center Bridging rather than a TCP/IP stack.