What Is IP Storage?

IP storage is a term for approaches to using the Internet Protocol (TCP/IP) in a storage area network, usually over Gigabit Ethernet. IP storage is an alternative to the Fibre Channel framework of the traditional SAN.

IP storage can extend the data storage capacity of a network indefinetly.

Common Abbreviations

SAN stands for Storage Area Network. IP stands for Internet Protocol. FC often stands for Fibre Channel.

Definitions

Storage networking is a system within which various remote storage devices are combined in such a way so that they appear attached to a local operating system. Internet Protocol (also known as TCP/IP) is a protocol for transmitting data over packet-switched internetworks. Fibre Channel is a giga-bit speed network technology used for storage networking.

Fibre Channel

Fibre Channel SANs use protocols to carry FC frames within IP packets or convert these frames to packets (iFCP) to ride over IP. On the other hand, non-Fibre Channel SANs such as IP storage use the iSCSI protocol to directly convert data to IP packets at reduced expense. The principal issues with Fibre Channel, including expense, complexity and interoperability, have driven the development of IP storage.

Concept

Think of IP storage as a network of linked hard disks, all running the same software, all capable of transferring data freely between them. IP storage thus increases the total storage capacity of a network by spreading the data out over the extent of the available network, in some cases worldwide.

Advantages

When first introduced in the mid-1990s, SANs showed a lot of promise over the Fibre Channel alternative. Taking advantage of common network hardware and technologies was supposed to make IP SANs less complicated to develop and use than Fibre Channel. Also, the hardware for IP storage is less expensive. Additionally, these technologies are widely used, so there are fewer interoperability issues and lower training costs.

TCI/IP Ubiquity

The ubiquity of TCP/IP networks could enable the connection of SANs worldwide. To this end, programmers have developed several technologies for the use of IP SANs. FCIP (Fibre Channel over IP) and iFCP (Internet Fibre Channel Protocol) offer hybrid approaches to extend Fibre Channel frameworks and to transfer from them to an IP storage network, while iSCSI (Internet SCSI) replaces Fibre Channel.