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It started for use primarily in the Supercomputer field, but has become the standard connection type for Storage Area Network s (SAN) in Enterprise Storage . Despite common connotations of its name, Fibre Channel signaling can run on both Twisted Pair Copper Wire and Fiber-optic Cable s. Fibre Channel Protocol (FCP) is the interface protocol of SCSI on the Fibre Channel. HISTORY Fibre Channel started in 1988, with ANSI standard approval in 1994, as a way to simplify the HIPPI system then in use for similar roles. HIPPI used a massive 50-pair cable with bulky connectors, and had limited cable lengths. Fibre Channel was primarily concerned with simplifying the connections and increasing distances, as opposed to increasing speeds. Later, designers added the goals of connecting SCSI disk storage, providing higher speeds and far greater numbers of connected devices. It also added support for any number of "upper layer" protocols, including SCSI , ATM , and IP , with SCSI being the predominant usage. FIBRE CHANNEL TOPOLOGIES There are three major Fibre Channel topologies, describing how a number of Ports are connected together. A ''port'' in Fibre Channel terminology is any entity that actively communicates over the network, not necessarily a Hardware Port . Port is usually implemented in a device such as disk storage, an HBA on server or a Fibre Channel Switch .
FIBRE CHANNEL LAYERS Fibre Channel is a layered protocol. It consists of 5 layers, namely:
FC0, FC1, and FC2 are also known as FC-PH, the physical layers of fibre channel. Fibre Channel routers operate up to FC4 level (i.e. they are in fact SCSI routers), switches up to FC2, and hubs on FC0 only. Fibre Channel products are available at 1 Gbit/s , 2 Gbit/s and 4 Gbit/s. An 8 Gbit/s standard is being developed. A 10 Gbit/s standard has been ratified, but is currently only used to interconnect switches. No 10 Gbit/s initiator or target products are available yet based on that standard. Products based on the 1, 2, 4 and 8 Gbit/s standards should be interoperable, and backward compatible. The 10 Gbit/s standard, however, is not backward compatible with any of the slower speed devices, as it differs considerably on FC1 level ( 64b/66b Encoding instead of 8b/10b encoding). PORTS The following types of ports are defined by Fibre Channel:
OPTICAL CARRIER MEDIUM VARIANTS on the left and older SC (typical for 100 MB/s speeds) on the right]] FIBRE CHANNEL INFRASTRUCTURE Fibre Channel switches are divided into two classes. These classes are not part of the standard, and the classification of every switch is a marketing decision of the manufacturer.
Brocade , Cisco and QLogic provide both directors and switches. If multiple switch vendors are used in the same fabric (i.e. fabric is ''heterogenous''), the fabric will default to "interoperability mode", that is to a pure standarized Fibre Channel protocol. Some proprietary, advanced features may be disabled. FIBRE CHANNEL HOST BUS ADAPTERS Fibre Channel HBA s are available for all major Open Systems , computer architectures, and buses, including PCI and SBus (obsolete today). Some are OS dependent. Each HBA has a unique World Wide Name (WWN), which is similar to an Ethernet MAC Address in that it uses an Organizationally Unique Identifier (OUI) assigned by the IEEE . However, WWNs are longer (8 bytes). There are two types of WWNs on a HBA; a node WWN (WWNN), which is shared by all ports on a host bus adapter, and a '''port WWN (WWPN)''', which is unique to each port. Some Fibre Channel HBA manufacturers are Emulex , LSI , QLogic and ATTO Technology . FIBRE CHANNEL REFERENCES ;RFCs:
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