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Fibre Channel
Layer 4. Protocol mapping
LUN masking
Layer 3. Common services
Layer 2. Network
Fibre Channel fabric
Fibre Channel zoning
Registered state change notification
Layer 1. Data link
Fibre Channel 8b/10b encoding
Layer 0. Physical

Fibre Channel (FC) is a high-speed data transfer protocol providing in-order, lossless[1] delivery of raw block data.[2] Fibre Channel is primarily used to connect computer data storage to servers[3][4] in storage area networks (SAN) in commercial data centers.

Fibre Channel networks form a switched fabric because the switches in a network operate in unison as one big switch. Fibre Channel typically runs on optical fiber cables within and between data centers, but can also run on copper cabling.[3][4] Supported data rates include 1, 2, 4, 8, 16, 32, 64, and 128 gigabit per second resulting from improvements in successive technology generations. The industry now notates this as Gigabit Fibre Channel (GFC).

There are various upper-level protocols for Fibre Channel, including two for block storage. Fibre Channel Protocol (FCP) is a protocol that transports SCSI commands over Fibre Channel networks.[3][4] FICON is a protocol that transports ESCON commands, used by IBM mainframe computers, over Fibre Channel. Fibre Channel can be used to transport data from storage systems that use solid-state flash memory storage medium by transporting NVMe protocol commands.


When the technology was originally devised, it ran over optical fiber cables only and, as such, was called "Fiber Channel". Later, the ability to run over copper cabling was added to the specification. In order to avoid confusion and to create a unique name, the industry decided to change the spelling and use the British English fibre for the name of the standard.[5]


Fibre Channel is standardized in the T11 Technical Committee of the International Committee for Information Technology Standards (INCITS), an American National Standards Institute (ANSI)-accredited standards committee. Fibre Channel started in 1988, with ANSI standard approval in 1994, to merge the benefits of multiple physical layer implementations including SCSI, HIPPI and ESCON.

Fibre Channel was designed as a serial interface to overcome limitations of the SCSI and HIPPI physical-layer parallel-signal copper wire interfaces. Such interfaces face the challenge of, among other things, maintaining signal timing coherence across all the data-signal wires (8, 16 and finally 32 for SCSI, 50 for HIPPI) so that a receiver can determine when all the electrical signal values are "good" (stable and valid for simultaneous reception sampling). This challenge becomes evermore difficult in a mass-manufactured technology as data signal frequencies increase, with part of the technical compensation being ever reducing the supported connecting copper-parallel cable length. See Parallel SCSI. FC was developed with leading-edge multi-mode optical fiber technologies that overcame the speed limitations of the ESCON protocol. By appealing to the large base of SCSI disk drives and leveraging mainframe technologies, Fibre Channel developed economies of scale for advanced technologies and deployments became economical and widespread.

Commercial products were released while the standard was still in draft.[6] By the time the standard was ratified lower speed versions were already growing out of use.[7] Fibre Channel was the first serial storage transport to achieve gigabit speeds[8] where it saw wide adoption, and its success grew with each successive speed. Fibre Channel has doubled in speed every few years since 1996.

In addition to a modern physical layer, Fibre Channel also added support for any number of "upper layer" protocols, including ATM, IP (IPFC) and FICON, with SCSI (FCP) being the predominant usage.

Fibre Channel has seen active development since its inception, with numerous speed improvements on a variety of underlying transport media. The following tables shows the progression of native Fibre Channel speeds:[9]

Fibre Channel variants[10]
Name Line-rate (gigabaud) Line coding Nominal throughput
per direction (MB/s)
Market availability
133 Mbit/s 0.1328125 8b10b 12.5 1993
266 Mbit/s 0.265625 8b10b 25 1994[6]
533 Mbit/s 0.53125 8b10b 50 ?
1GFC (Gen 1) 1.0625 8b10b 100 1997
2GFC (Gen 2) 2.125 8b10b 200 2001
4GFC (Gen 3) 4.25 8b10b 400 2004
8GFC (Gen 4) 8.5 8b10b 800 2008
16GFC (Gen 5) 14.025 64b66b 1,600 2011
32GFC (Gen 6) 28.05 256b257b 3,200 2016[11]
64GFC (Gen 7) 28.9 256b257b (FC-FS-5) 6,400 2020
128GFC (Gen 8) 57.8 256b257b 12,800 Planned 2024

FC used throughout all applications for Fibre Channel infrastructure and devices, including edge and ISL interconnects. Each speed maintains backward compatibility at least two previous generations (I.e., 32GFC backward compatible to 16GFC and 8GFC)

Inter-Switch Link variants[12]
Name Line-rate (gigabaud) Line coding Nominal throughput
per direction (MB/s)
Market availability
10GFC 10.51875 64b66b 1,200 2009
128GFC (Gen 6) 28.05 × 4 256b257b 12,800 2016[11]
256GFC (Gen 7) 28.9 × 4 256b257b 25,600 2020

Inter-Switch Links, ISLs, are usually multi-lane interconnects used for non-edge, core connections, and other high speed applications demanding maximum bandwidth. ISL’s utilize high bit-rates to accommodate the funneling of edge connections. Some ISL solutions are vendor-proprietary.


Two major characteristics of Fibre Channel networks are in-order delivery and lossless delivery of raw block data. Lossless delivery of raw data block is achieved based on a credit mechanism.[1]


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. This port is usually implemented in a device such as disk storage, a Host Bus Adapter (HBA) network connection on a server or a Fibre Channel switch.[3]

Topology diagram of a Fibre Channel point-to-point connection
Attribute Point-to-point Arbitrated loop Switched fabric
Max ports 2 127 ~16777216 (224)
Address size 8-bit ALPA 24-bit port ID
Side effect of port failure Link fails Loop fails (until port bypassed)
Access to medium Dedicated Arbitrated Dedicated


Fibre Channel does not follow the OSI model layering, and is split into five layers:

Fibre Channel is a layered technology that starts at the physical layer and progresses through the protocols to the upper level protocols like SCSI and SBCCS.

This diagram from FC-FS-4 defines the layers.

Layers FC-0 are defined in Fibre Channel Physical Interfaces (FC-PI-6), the physical layers of Fibre Channel.

Fibre Channel products are available at 1, 2, 4, 8, 10, 16 and 32 and 128 Gbit/s; these protocol flavors are called accordingly 1GFC, 2GFC, 4GFC, 8GFC, 10GFC, 16GFC, 32GFC or 128GFC. The 32GFC standard was approved by the INCITS T11 committee in 2013, and those products became available in 2016. The 1GFC, 2GFC, 4GFC, 8GFC designs all use 8b/10b encoding, while the 10GFC and 16GFC standard uses 64b/66b encoding. Unlike the 10GFC standards, 16GFC provides backward compatibility with 4GFC and 8GFC since it provides exactly twice the throughput of 8GFC or four times that of 4GFC.


FC topologies and port types: This diagram shows how N_Ports can be connected to a fabric or to another N_Port. A Loop Port (L_Port) communicates through a shared loop and is rarely used anymore.

Fibre Channel ports come in a variety of logical configurations. The most common types of ports are:

Fibre Channel Loop protocols create multiple types of Loop Ports:

If a port can support loop and non-loop functionality, the port is known as:

A Port has a physical structure as well as logical or virtual structure. This diagram shows how a virtual port may have multiple physical ports and vice versa.

Ports have virtual components and physical components and are described as:

The following types of ports are also used in Fibre Channel:

Media and modules

This section is missing information about legacy copper interfaces. Please expand the section to include this information. Further details may exist on the talk page. (November 2023)
This section appears to contradict itself. Please see the talk page for more information. (November 2023)
Fibre Channel predominantly uses SFP/SFP+ modules with LC connector and duplex cabling, but 128GFC uses QSFP28 modules with MPO connectors and ribbon cabling.

The Fibre Channel physical layer is based on serial connections that use fiber optics to copper between corresponding pluggable modules. The modules may have a single lane, dual lanes or quad lanes that correspond to the SFP, SFP-DD and QSFP form factors. Fibre Channel does not use 8- or 16-lane modules (like CFP8, QSFP-DD, or COBO used in 400GbE) and there are no plans to use these expensive and complex modules.

The small form-factor pluggable transceiver (SFP) module and its enhanced version SFP+, SFP28 and SFP56 are common form factors for Fibre Channel ports. SFP modules support a variety of distances via multi-mode and single-mode optical fiber as shown in the table below. SFP modules use duplex fiber cabling with LC connectors.

SFP-DD modules are used in high-density applications that need to double the throughput of traditional SFP ports.

SFP-DD modules are used for high-density applications that need to double the throughput of an SFP Port. SFP-DD is defined by the SFP-DD MSA and enables breakout to two SFP ports. Two rows of electrical contacts enable doubling the throughput of SFP modules in a similar fashion as QSFP-DD.

The quad small form-factor pluggable (QSFP) module began being used for switch inter-connectivity and was later adopted for use in 4-lane implementations of Gen-6 Fibre Channel supporting 128GFC. QSFP uses either LC connectors for 128GFC-CWDM4 or MPO connectors for 128GFC-SW4 or 128GFC-PSM4. MPO cabling uses 8- or 12-fiber cabling infrastructure that connects to another 128GFC port or may be broken out into four duplex LC connections to 32GFC SFP+ ports. Fibre Channel switches use either SFP or QSFP modules.

Transmitter[17] Medium variant Distance
Fiber (SMF)
12,800 1,310 nm longwave light 128GFC-PSM4 0.5m - 0.5 km
1,270, 1,290, 1,310 and 1,330 nm longwave light 128GFC-CWDM4 0.5 m – 2 km
6,400 1,310 nm longwave light 64GFC-LW 0.5m - 10 km
3,200 1,310 nm longwave light 3200-SM-LC-L 0.5 m - 10 km
1,600 1,310 nm longwave light[ITS 1] 1600-SM-LC-L[ITS 2] 0.5 m – 10 km
1,490 nm longwave light[ITS 1] 1600-SM-LZ-I[ITS 2] 0.5 m – 2 km
800 1,310 nm longwave light[ITS 3] 800-SM-LC-L[ITS 4] 2 m – 10 km
800-SM-LC-I[ITS 4] 2 m – 1.4 km
400 1,310 nm longwave light[ITS 3][ITS 5] 400-SM-LC-L[ITS 6] 2 m – 10 km
400-SM-LC-M[ITS 4] 2 m – 4 km
400-SM-LL-I[ITS 7] 2 m – 2 km
200 1,550 nm longwave light[ITS 8] 200-SM-LL-V[ITS 8] 2 m – 50 km
1,310 nm longwave light[ITS 5][ITS 3] 200-SM-LC-L[ITS 6] 2 m – 10 km
200-SM-LL-I[ITS 7] 2 m – 2 km
100 1,550 nm longwave light[ITS 8] 100-SM-LL-V[ITS 8] 2 m – 50 km
1,310 nm longwave light[ITS 9][ITS 3] 100-SM-LL-L[ITS 10]
100-SM-LC-L[ITS 6]
2 m – 10 km
100-SM-LL-I[ITS 10] 2 m – 2 km
Fiber (MMF)
12,800 850 nm shortwave light[ITS 11][ITS 12][ITS 13] 128GFC-SW4 0 – 100 m
6,400 64GFC-SW 0 - 100m
3,200 3200-SN 0 – 100 m
1,600 1600-M5F-SN-I[ITS 14] 0.5 m – 125 m
1600-M5E-SN-I[ITS 14] 0.5–100 m
1600-M5-SN-S[ITS 14] 0.5–35 m
1600-M6-SN-S[ITS 15] 0.5–15 m
800 800-M5F-SN-I[ITS 14] 0.5–190 m
800-M5E-SN-I[ITS 16] 0.5–150 m
800-M5-SN-S[ITS 16] 0.5–50 m
800-M6-SN-S[ITS 16] 0.5–21 m
400 400-M5F-SN-I[ITS 14] 0.5–400 m
400-M5E-SN-I[ITS 16] 0.5–380 m
400-M5-SN-I[ITS 17] 0.5–150 m
400-M6-SN-I[ITS 17] 0.5–70 m
200 200-M5E-SN-I[ITS 16] 0.5–500 m
200-M5-SN-I[ITS 17] 0.5–300 m
200-M6-SN-I[ITS 17] 0.5–150 m
100 100-M5E-SN-I[ITS 18] 0.5–860 m
100-M5-SN-I[ITS 19] 0.5–500 m
100-M6-SN-I[ITS 19] 0.5–300 m
100-M5-SL-I[ITS 19] 2–500 m
100-M6-SL-I[ITS 20] 2–175 m
Multi-mode fiber Fiber diameter FC media designation
OM1 62.5 μm M6
OM2 50 μm M5
OM3 50 μm M5E
OM4 50 μm M5F
OM5 50 μm N/A

Modern Fibre Channel devices support SFP+ transceiver, mainly with LC (Lucent Connector) fiber connector. Older 1GFC devices used GBIC transceiver, mainly with SC (Subscriber Connector) fiber connector.

Storage area networks

The Fibre Channel SAN connects servers to storage via Fibre Channel switches.

The goal of Fibre Channel is to create a storage area network (SAN) to connect servers to storage.

The SAN is a dedicated network that enables multiple servers to access data from one or more storage devices. Enterprise storage uses the SAN to backup to secondary storage devices including disk arrays, tape libraries, and other backup while the storage is still accessible to the server. Servers may access storage from multiple storage devices over the network as well.

SANs are often designed with dual fabrics to increase fault tolerance. Two completely separate fabrics are operational and if the primary fabric fails, then the second fabric becomes the primary.


Fibre Channel director with SFP+ modules and LC optical fiber connectors with Optical Multimode 3 (OM3) fiber (aqua)

Fibre Channel switches can be 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:

A fabric consisting entirely of one vendors products is considered to be homogeneous. This is often referred to as operating in its "native mode" and allows the vendor to add proprietary features which may not be compliant with the Fibre Channel standard.

If multiple switch vendors are used within the same fabric it is heterogeneous, the switches may only achieve adjacency if all switches are placed into their interoperability modes. This is called the "open fabric" mode as each vendor's switch may have to disable its proprietary features to comply with the Fibre Channel standard.

Some switch manufacturers offer a variety of interoperability modes above and beyond the "native" and "open fabric" states. These "native interoperability" modes allow switches to operate in the native mode of another vendor and still maintain some of the proprietary behaviors of both. However, running in native interoperability mode may still disable some proprietary features and can produce fabrics of questionable stability.

Host bus adapters

Dual port 8 Gb FC host bus adapter card
Dual port 16 Gb FC host bus adapter card

Fibre Channel HBAs, as well as CNAs, are available for all major open systems, computer architectures, and buses, including PCI and SBus. HBAs connect servers to the Fibre Channel network and are part of a class of devices known as translation devices. 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 an HBA; a World Wide Node Name (WWNN), which can be shared by some or all ports of a device, and a World Wide Port Name (WWPN), which is necessarily unique to each port. Adapters or routers can connect Fibre Channel networks to IP or Ethernet networks.[18]

See also


  1. ^ a b "Fibre Channel Performance: Congestion, Slow Drain, and Over Utilization, Oh My!" (PDF). Fibre Channel Industry Association. February 6, 2018. Archived (PDF) from the original on 2018-03-01. Retrieved 2018-02-28.
  2. ^ "Fibre Channel Basics" (PDF). Apple. Archived (PDF) from the original on 2017-08-29. Retrieved 2018-03-22.
  3. ^ a b c d e Preston, W. Curtis (2002). "Fibre Channel Architecture". Using SANs and NAS. Sebastopol, CA: O'Reilly Media. pp. 19–39. ISBN 978-0-596-00153-7. OCLC 472853124.
  4. ^ a b c Riabov, Vladmir V. (2004). "Storage Area Networks (SANs)". In Bidgoli, Hossein (ed.). The Internet Encyclopedia. Volume 3, P-Z. Hoboken, NJ: John Wiley & Sons. pp. 329–338. ISBN 978-0-471-68997-3. OCLC 55610291.
  5. ^ "Fibre Channel internals". Introduction to Storage Area Networks. IBM. 2016. p. 33.
  6. ^ a b IBM 7319 Model 100 Fibre Channel Switch 16/266 and IBM Fibre Channel Adapter/266
  7. ^ Fibre Channel Physical and Signaling Interface (FC-PH) Rev 4.3, June 1, 1994
  8. ^ Tom Clark, Designing Storage Area Networks: A Practical Reference for Implementing Fibre Channel and IP SANs
  9. ^ "Roadmaps". Fibre Channel Industry Association. Retrieved 2023-03-05.
  10. ^ Fibre Channel Speedmap
  11. ^ a b Brocade 32Gb platform released, "Brocade G620 Gen 6 Fibre Channel Switch Released". March 2016. Archived from the original on 2016-04-04. Retrieved 2016-04-04.
  12. ^ Fibre Channel Speedmap
  13. ^ a b c d e f g Fibre Channel - Framing and Signaling - 4 (FC-FS-4)
  14. ^ a b c d e f g h i j k l Fibre Channel - Switch Fabric 6 (FC-SW-6)
  15. ^ a b c d "BCFA in a Nutshell Study Guide for Exam" (PDF). Brocade Communications, Inc. February 2014. Archived (PDF) from the original on September 7, 2015. Retrieved June 28, 2016.
  16. ^ "Cisco MDS 9000 Family Fabric Manager Configuration Guide, Release 4.x". Cisco Systems, Inc. November 11, 2013. Archived from the original on August 21, 2016. Retrieved June 28, 2016.
  17. ^ Transmitter values listed are the currently specified values for the variant listed. Some older versions of the FC standards listed slightly different values (however, the values listed here fall within the +/− variance allowed). Individual variations for each specification are listed in the references associated with those entries in this table. FC-PH = X3T11 Project 755D; FC-PH-2 = X3T11 Project 901D; FC-PI-4 = INCITS Project 1647-D; FC-PI-5 = INCITS Project 2118D. Copies are available from INCITS Archived 2010-09-15 at the Wayback Machine.
  18. ^ "Hardware". 25 September 2012.

INCITS standards

  1. ^ a b FC-PI-5 Clause 6.3
  2. ^ a b FC-PI-5 Clause 8.1
  3. ^ a b c d FC-PI-4 Clause 6.3
  4. ^ a b c FC-PI-4 Clause 8.1
  5. ^ a b FC-PH-2 lists 1300nm (see clause 6.1 and 8.1)
  6. ^ a b c FC-PI clause 8.1
  7. ^ a b FC-PH-2 clause 8.1
  8. ^ a b c d FC-PI-4 Clause 11
  9. ^ FC-PH lists 1300nm (see clause 6.1 and 8.1)
  10. ^ a b FC-PH Clause 8.1
  11. ^ FC-PI-5 Clause 6.4
  12. ^ FC-PI-4 Clause 6.4
  13. ^ The older FC-PH and FC-PH-2 list 850nm (for 62.5μm cables) and 780nm (for 50μm cables)(see clause 6.2, 8.2, and 8.3)
  14. ^ a b c d e FC-PI-5 Clause 8.2
  15. ^ FC-PI-5 Annex A
  16. ^ a b c d e FC-PI-4 Clause 8.2
  17. ^ a b c d FC-PI Clause 8.2
  18. ^ PC-PI-4 Clause 8.2
  19. ^ a b c PC-PI Clause 8.2
  20. ^ FC-PH Annex C and Annex E


Further reading