FC Protocol Stack

It is easier to understand a communication protocol by viewing it as a structure of independent layers.

FCP defines the communication protocol in five layers: FC-0 through FC-4 (except FC-3 layer, which is not implemented).

FC-4 Upper Layer Protocol:

FC-4 is the uppermost layer in the FCP stack.

This layer defines the application interfaces and the way Upper Layer Protocols (ULPs) are mapped to the lower FC layers.

FC-2 Transport Layer

The FC-2 is the transport layer that contains the payload, addresses of the source and destination ports, and link control information.

The FC-2 layer provides Fibre Channel addressing, structure, and organization of data (frames, sequences, and exchanges).

It also defines fabric services, classes of service, flow control, and routing.

FC-1 Transmission Protocol

This layer defines the transmission protocol that includes serial encoding and decoding rules, special characters used, and error control.

At the transmitter node, an 8-bit character is encoded into a 10-bit transmissions character.

At the receiver node, the 10-bit character is passed to the FC-1 layer, which decodes the 10-bit character into the original 8-bit character.

FC-0 Physical Interface

FC-0 is the lowest layer in the FCP stack.

This layer defines the physical interface, media, and transmission of raw bits.

The FC-0 specification includes cables, connectors, and optical and electrical parameters for a variety of data rates.

The FC transmission can use both electrical and optical media.