IP SAN (Internet Protocol storage area network)
An IP SAN is a dedicated storage area network (SAN) that allows multiple servers to access pools of shared block storage devices using storage protocols that depend on the Internet Engineering Taskforce standard Internet Protocol suite.
The storage protocols designed to move block-based data between a host server and storage array include the Internet Small Computer Systems Interface (iSCSI), Fibre Channel over IP (FCIP) and Internet Fibre Channel Protocol (iFCP).
The most common type of IP SAN uses iSCSI to encapsulate SCSI commands and assemble data into packets for transfer between the host servers and storage devices. IP SAN protocols typically run over a standard Ethernet network and use the Transmission Control Protocol/Internet Protocol (TCP/IP) for communication. An IP SAN for block-based data is often referred to as an iSCSI SAN.
An IP SAN is generally viewed as lower cost, less complex and simpler to manage than an FC SAN. An FC SAN requires special hardware such as host bus adapters and FC switches, whereas the IP SAN can use commodity Ethernet networking hardware. One potential disadvantage of an IP SAN is higher latency than an FC SAN, which uses deterministic layer 2 switching technology.
