Internet Fibre Channel Protocol

Internet Fibre Channel Protocol (iFCP) is a gateway to gateway protocol which provides fibre channel fabric services to fibre channel devices over a TCP/IP network.

Overview

Within the iFCP congestion control and error detection and recovery are provided through the use of TCP (Transmission Control Protocol). The primary objective of iFPC is to allow existing fibre channel devices to be network and interconnected over an IP based network at wire speeds.

The method of frame address translation defined and the protocol permit the fibre channel storage devices to be attached to an IP-based fabric by using transparant gateways.

Unlike a layered network architecture (exemplified by the OSI model), a fibre channel network is largely specified by functional elements and the interfaces between them making the fibre channel network the fundamental entity in fibre channel. The elements within the fibre channel network consist of any of the following:

• N PORTs -- The end points for fibre channel traffic
• FC Devices -- The fibre channel devices to which the N_PORTs provide access.
• Fabric Ports -- The interfaces within a fibre channel network that provide attachement for an N_PORT.
• The network infrastructure for carrying frame traffic between N_PORTs.
• Within a switched or mixed fabric, a set of auxiliary servers, including a name server for device discovery and network address resolution.

The iFCP protocol enables the implementation of fibre channel functionality over an IP network within which the fibre channel switching and routing infrastructure is replaced by IP components and technology.

The iFCP protocol layer's main function is to transport fibre channel frame images between N_PORTs attached both locally and remotely. The iFCP layer encapsulates and routes the fibre channel frames that make up each fibre channel information unit via a predetermined TCP connection for transport across the IP network when transporting frames to a remote N_PORT.

When the iFCP receives fibre channel frame images from the IP network, the iFCP layer de-encapsulates and delivers each frame to the appropriate N_PORT.

The following types of traffic are processed by the iFCP layer:

• FC-4 frame images associated with a fibre channel application protocol.
• FC-2 frames comprising fibre channel link service requests and responses
• Fibre channel broadcast frames
• iFCP control messages required to setup, manage or terminate an iFCP session.

See Also

• Fibre Channel over IP (FCIP)
• Internet SCSI (iSCSI)