ITWissen.info - Tech know how online

fibre channel reference model

The Fibre Channel is built on a five-layer layer model. These five layers are designated FC-0, FC-1, FC-2, FC-3 and FC-4 and support specific transmission functions and service characteristics for transmission. The FC layer model is somewhat similar to the OSI reference model.

The lowest layerFibre Channel 0, (FC-0) is the physical layer in which the physical connection, the FC transmission media with their parameters and connections, and the data rates are specified. These are 133 Mbit/s, 266 Mbit/s, 531 Mbit/s and 1.0625 Gbit/s with payloads of 12.5 MB/s, 25 MB/s, 50 MB/s and 100 MB/s respectively. Optical fiber, coaxial cable and STP cable are specified as transmission media, and LEDs, lasers and ECL technology are specified as drivers.

At the Fibre Channel 1, (FC-1) level, the encoding and decoding of the signals to be transmitted takes place. Fibre Channel uses 8B/10B coding to improve transmission characteristics

Flow control with Fibre Channel

Flow control with Fibre Channel

Fibre Channel is designed for high-speed transmission of large amounts of data, which is expressed in the length of the FC data frame, which can be 2 Kbytes and larger with variable length.

The Fibre Channel 2, (FC-2) layer is where flow control takes place, which operates on a credit basis and has two mechanisms: buffer-to-buffer flow control( BB_Buffer) for links and end-to-end flow control between two end devices.

Service characteristics of the different FC classes

Service characteristics of the different FC classes

In order to ensure the most efficient data transmission for the different types of traffic, Fibre Channel distinguishes between several FC service classes. These are implemented in the FC-2 layer by controlling the data sequences. These service classes are confirmed and unconfirmed connectionless services.

The Fibre Channel 3, (FC-3) layer supports services such as multicast broadcasts, where one piece of information is sent to many receivers, and striping, where bandwidth is increased by connecting ports in parallel.

Fibre Channel layer model

Fibre Channel layer model

The next higher FC layer, Fibre Channel 4, (FC-4) defines the application interfaces and adapts the higher protocols to Fibre Channel. The known access mechanisms of local networks are based on this layer, so that Fibre Channel can also be used in LANs. In addition to network protocols such as the IP protocol, this layer also supports bus protocols such as Small ComputerSystem Interface( SCSI). Different data formats can be transported simultaneously via the physical interface. Thus from SCSI, Intelligent Peripheral Interface( IPI), High Performance Parallel Interface( HIPPI), AAL5, in Single Byte Command Code Set( SBCCS) and IEEE 802.2.

Above FC-4 are the Upper Layer Protocols( ULP). These application-oriented protocols determine whether an FC network operates as an IP network or as a storagearea network ( SAN).

Informations:
Englisch: fibre channel reference model
Updated at: 03.10.2013
#Words: 425
Links: layer, layer model, fiber coupler (FC), transmission, service
Translations: DE
Sharing:    

All rights reserved DATACOM Buchverlag GmbH © 2024