Fördelarna med Fibre Channel-teknik återspeglas främst

(1) Hög bandbredd, dataöverföringshastigheten på 200MB/s har uppnåtts för närvarande, och 400MB/s har klarat testet;

(2) Hög-adresseringskapacitet och kapacitetsutvidgningskapacitet, som kan komma åt 16 miljoner noder;

(3) Mycket centraliserad data och global delning av lagringskapacitet;

(4) Det långa anslutningsavståndet mellan varje par av noder, den optiska multi-modekabeln kan nå 500 meter och den optiska enkel-modekabeln kan nå 10 kilometer;

(5) Modulär expansion och anslutning;

(6) Hög tillgänglighet eller -feltolerant servicesystem kan upprättas genom att använda optiska fiberomkopplare och relaterad programvara;

(7) Det kan underlätta etableringen av lastbalansering och serverklustersystem.

Fibre Channel technology is a new technology developed by combining the advantages of "channel technology" and "network technology": channel technology is a hardware-intensive technology, because it is designed to quickly transmit a large amount of data in the buffer area, which can Connect devices directly without using too much logic; network technology is software-intensive because packets need to be routed across the network to one node among many devices, and network technology has the ability to operate a large number of nodes. Fibre Channel technology has been designed from the outset to combine the above-mentioned advantages of channel technology and network technology. Five independent layers are defined in the Fibre Channel protocol, from the physical medium to the high-level protocol transmitted in the Fibre Channel, which contains the overall picture of the Fibre Channel technology. The following are the functional modules of these five layers: ① FC-0, physical layer, defines the physical port characteristics of the connection, including the physical characteristics, electrical characteristics and optical characteristics of the medium and connectors (drivers, receivers, transmitters, etc.), transmission speed and some other port characteristics. Physical media are fiber optic, twisted pair, and coaxial cable. This layer defines how light travels on optical fibers and how the transmitter and receiver work over various physical media.

②FC-1, transmission protocol, FC-1 stipulates the encoding method and transmission protocol of 8B/10B according to the ANSI X3 T11 standard, including serial encoding, decoding rules, special characters and error control. The transfer encoding must be DC balanced to meet the electrical requirements of the receiving unit. Special characters ensure that what appears in the serial bit stream is a short character length and a certain transition signal for clock recovery. This layer is responsible for taking a sequence of signals and encoding them into usable character data.

③ FC-2, frame protocol, defines the transmission mechanism, including frame positioning, frame header content, usage rules, and flow control. Fibre Channel data frames are of variable length and addressable. The length of the Fibre Channel data frame used to transmit data is up to 2K, so it is very suitable for the transmission of large-capacity data. The content of the frame header includes control information, source address, destination address, transmission sequence identification and switching equipment. The 64-byte optional header is used for protocol mapping when other types of networks are transmitted over Fibre Channel. Fibre Channel relies on the contents of the data frame header to initiate operations.

④ FC-3, public service, provides public services with advanced features, that is, structural protocol and flow control between ports, it defines three services: striping (Striping), search group (Hunt Group) and multicast (Multicast) ). The purpose of striping is to use multiple ports to transmit in parallel on multiple connections, so that the I/O transmission bandwidth can be extended to a corresponding multiple; the search group is used for multiple ports to respond to an address with the same name. Improve efficiency by reducing the probability of reaching a "busy" port; multicast is used to deliver a message to multiple destinations.

⑤ FC-4, the protocol mapping layer, defines the mapping relationship between the bottom layer of Fibre Channel and the upper layer protocol (Upper Layer Protocol) and the application interface with the current standard. The current standard here includes all existing channel standards and network protocols. , such as SCSI interface and IP, ATM, HIPPI, etc.

Det kan ses att Fibre Channel-protokollstacken är överföringsbäraren för olika-högnivådataprotokoll, särskilt överföringen av SCSI- och IP-data. Processen att överföra hög-dataprotokollet som bärare är faktiskt en process för att mappa hög-dataprotokollet till protokollstackens fysiska lageröverföringstjänst. Bland dem är det mest använda Fibre Channel Protocol mappningen av SCSI-data, kommandon och statusinformation till FC:s fysiska lageröverföringstjänst. FCP har oberoendet att arbeta med alla Fiber Path-topologier och alla typer av tjänster.