View source for Engineering:Fibre Channel

{{Short description|Computer storage networking technology}}

'''Fibre Channel''' ('''FC''') is a high-speed data transfer protocol providing in-order, lossless<ref name="fibrechannel.org">{{cite web |url=http://fibrechannel.org/wp-content/uploads/2018/02/FCIA_Fibre_Channel_Performance_Congestion_Slowdrain_and_Over_Utilization_Final.pdf |title=Archived copy |access-date=2018-02-28 |url-status=live |archive-url=https://web.archive.org/web/20180301164420/http://fibrechannel.org/wp-content/uploads/2018/02/FCIA_Fibre_Channel_Performance_Congestion_Slowdrain_and_Over_Utilization_Final.pdf |archive-date=2018-03-01 }}</ref> delivery of raw block data.<ref>{{cite web |url=https://images.apple.com/server/docs/Fibre_Channel_Basics_TB_v10.4.pdf |title=Archived copy |access-date=2018-03-22 |url-status=live |archive-url=https://web.archive.org/web/20170829075557/http://images.apple.com/server/docs/Fibre_Channel_Basics_TB_v10.4.pdf |archive-date=2017-08-29 }}</ref> Fibre Channel is primarily used to connect [[Computer data storage|computer data storage]] to [[Server (computing)|servers]]<ref name="Preston">{{cite book |last1=Preston |first1=W. Curtis |title=Using SANs and NAS |year=2002 |publisher=O'Reilly Media |location=Sebastopol, CA |isbn=978-0-596-00153-7 |oclc=472853124 |chapter=Fibre Channel Architecture |pages=19–39 }}</ref><ref name="Riabov">{{cite book |last1=Riabov |first1=Vladmir V. |editor1-first=Hossein  |editor1-last=Bidgoli |title=The Internet Encyclopedia. Volume 3, P-Z |year=2004 |publisher={{wipe|John Wiley & Sons}} |location=Hoboken, NJ |isbn=978-0-471-68997-3 |oclc=55610291 |chapter=Storage Area Networks (SANs) |pages=329–338 }}</ref> in [[Storage area network|storage area network]]s (SAN) in commercial [[Data center|data center]]s.

Fibre Channel networks form a [[Switched fabric|switched fabric]] because the switches in a network operate in unison as one big switch.  Fibre Channel typically runs on [[Engineering:Optical fiber|optical fiber]] cables within and between data centers, but can also run on copper cabling.<ref name="Preston" /><ref name="Riabov" /> 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. [[Engineering:Fibre Channel Protocol|Fibre Channel Protocol]] (FCP) is a protocol that transports SCSI commands over Fibre Channel networks.<ref name=Preston /><ref name=Riabov /> 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|flash memory]] storage medium by transporting [[Engineering:NVM Express|NVMe]] protocol commands.

== Etymology ==
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.<ref name=Tate>{{cite book |title=Introduction to Storage Area Networks |year=2016 |publisher=[[Company:IBM|IBM]] |chapter=Fibre Channel internals |pages=33 }}</ref>

== History ==
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 [[Engineering:SCSI connector|SCSI]], [[Engineering:HIPPI|HIPPI]]  and [[ESCON]].

Fibre Channel was designed as a [[Serial communication|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 [[Engineering:Parallel SCSI|Parallel SCSI]]. FC was developed with leading-edge [[Engineering:Multi-mode optical fiber|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 [[Finance:Economies of scale|economies of scale]] for advanced technologies and deployments became economical and widespread.

Commercial products were released while the standard was still in draft.<ref name=ZG940168>[https://www-01.ibm.com/common/ssi/rep_ca/8/877/ENUSZG94-0168/index.html IBM 7319 Model 100 Fibre Channel Switch 16/266 and IBM Fibre Channel Adapter/266]</ref> By the time the standard was ratified lower speed versions were already growing out of use.<ref>Fibre Channel Physical and Signaling Interface (FC-PH) Rev 4.3, June 1, 1994</ref> Fibre Channel was the first serial storage transport to achieve gigabit speeds<ref>[https://www.pearsonhighered.com/assets/samplechapter/0/3/2/1/0321136500.pdf Tom Clark, Designing Storage Area Networks: A Practical Reference for Implementing Fibre Channel and IP SANs]</ref> where it saw wide adoption, and its success grew with each successive speed. Fibre Channel has doubled in speed every few years since 1996.

Fibre Channel has seen active development since its inception, with numerous speed improvements on a variety of underlying transport media. The following table shows the progression of native Fibre Channel speeds:<ref>{{cite web
 |title       = Roadmaps
 |url         = https://fibrechannel.org/roadmap/
 |publisher   = Fibre Channel Industry Association
 |access-date  = 2023-03-05
}}</ref>
{| class="wikitable sortable" style="margin: 1em auto 1em auto"
|+ {{vanchor|Fibre Channel variants}}<ref>[https://fibrechannel.org/roadmap/ Fibre Channel Speedmap]</ref>
! Name
! Line-rate ([[Baud|gigabaud]])
! Line coding
! Nominal throughput<br />per direction (MB/s)
! Market availability
|-
! 133 Mbit/s
| 0.1328125
| 8b10b
| align="right" | 12.5
| 1993
|-
! 266 Mbit/s
| 0.265625
| 8b10b
| align="right" | 25
| 1994<ref name=ZG940168 />
|-
! 533 Mbit/s
| 0.53125
| 8b10b
| align="right" | 50
| {{dunno}}
|-
! 1GFC
| 1.0625
| 8b10b
| align="right" | 100
| 1997
|-
! 2GFC
| 2.125
| 8b10b
| align="right" | 200
| 2001
|-
! 4GFC
| 4.25
| 8b10b
| align="right" | 400
| 2004
|-
! 8GFC
| 8.5
| 8b10b
| align="right" | 800
| 2008
|-
! 10GFC
| 10.51875
| 64b66b
| align="right" | 1,200
| 2008
|-
! 16GFC
| 14.025
| 64b66b
| align="right" | 1,600
| 2011
|-
! 32GFC (Gen 6)
| 28.05
| 256b257b
| align="right" | 3,200
| 2016<ref name=g620release>Brocade 32Gb platform released, Storagereview.com {{cite web |url=http://www.storagereview.com/brocade_g620_gen_6_fibre_channel_switch_released |title=Brocade G620 Gen 6 Fibre Channel Switch Released |date=March 2016 |access-date=2016-04-04 |url-status=live |archive-url=https://web.archive.org/web/20160404014046/http://www.storagereview.com/brocade_g620_gen_6_fibre_channel_switch_released |archive-date=2016-04-04 }}</ref>
|-
! 64GFC (Gen 7)
| 28.9
| 256b257b (FC-FS-5)
| align="right" | 6,400
| 2020
|-
! 128GFC (Gen 6)
| 28.05 ×4
| 256b257b
| align="right" | 12,800
| 2016<ref name=g620release />
|-
! 256GFC (Gen 7)
| 28.9 ×4
| 256b257b
| align="right" | 25,600
| 2020
|-
! 128GFC (Gen 8)
| 57.8
|256b257b
| align="right" | 12,800
|Planned 2024
|}
{{Reflist|group=v}}In addition to a modern physical layer, Fibre Channel also added support for any number of "upper layer" protocols, including [[Asynchronous Transfer Mode|ATM]], [[Internet Protocol|IP]] ([[IPFC]]) and FICON, with [[Engineering:SCSI|SCSI]] ([[Engineering:Fibre Channel Protocol|FCP]]) being the predominant usage.

==Characteristics==
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.<ref name="fibrechannel.org"/>

==Topologies==
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 [[Engineering:Computer port (hardware)|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.<ref name=Preston />

[[Image:Ben ptpt.svg|thumb|320px|right|Topology diagram of a Fibre Channel point-to-point connection]]
* '''{{visible anchor|Point-to-point}}''' (see ''FC-FS-3''). Two devices are connected directly to each other using N ports. This is the simplest topology, with limited connectivity.<ref name=Preston /> The bandwidth is dedicated. 
* '''[[Arbitrated loop]]''' (see ''FC-AL-2''). In this design, all devices are in a loop or ring, similar to [[Token Ring]] networking. Adding or removing a device from the loop causes all activity on the loop to be interrupted. The failure of one device causes a break in the ring. Fibre Channel hubs exist to connect multiple devices together and may bypass failed ports. A loop may also be made by cabling each port to the next in a ring.
** A minimal loop containing only two ports, while appearing to be similar to point-to-point, differs considerably in terms of the protocol.
** Only one pair of ports can communicate concurrently on a loop.
** Maximum speed of 8GFC.
** Arbitrated Loop has been rarely used after 2010 and its support is being discontinued for new gen switches.
* '''Switched Fabric''' (see ''FC-SW-6''). In this design, all devices are connected to Fibre Channel switches, similar conceptually to modern [[Ethernet]] implementations. Advantages of this topology over point-to-point or Arbitrated Loop include:
** The Fabric can scale to tens of thousands of ports.
** The switches manage the state of the Fabric, providing optimized paths via Fabric Shortest Path First (FSPF) data routing protocol.
** The traffic between two ports flows through the switches and not through any other ports like in Arbitrated Loop.
** Failure of a port is isolated to a link and should not affect operation of other ports.
** Multiple pairs of ports may communicate simultaneously in a Fabric.

{| class="wikitable sortable" style="margin: 1em auto 1em auto"
|-
! Attribute
! Point-to-point
! Arbitrated loop
! Switched fabric
|-
! Max ports
|| 2 || 127 || ~16777216 (2<sup>24</sup>)
|-
! Address size
| {{N/A}} || 8-[[Bit|bit]] ALPA || 24-bit port ID
|-
! Side effect of port failure
|| Link fails || Loop fails (until port bypassed) || {{N/A}}
|-
! Access to medium
|| Dedicated || Arbitrated || Dedicated
|}

== Layers ==
Fibre Channel does not follow the [[OSI model]] layering, and is split into five layers:
[[File:Fibre Channel layers.svg|thumb|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.]]
* '''FC-4''' – Protocol-mapping layer, in which upper level protocols such as [[Engineering:NVM Express|NVM Express]] (NVMe), [[Engineering:SCSI|SCSI]], IP, and FICON are encapsulated into Information Units (IUs) for delivery to FC-2. Current FC-4s include FCP-4, FC-SB-5, and FC-NVMe.
* '''FC-3''' – Common services layer, a thin layer that could eventually implement functions like [[Encryption|encryption]] or RAID redundancy algorithms; multiport connections;
* '''FC-2''' – Signaling Protocol, defined by the Fibre Channel Framing and Signaling 4 (FC-FS-5) standard, consists of the low level [[Fibre Channel network protocols]]; port to port connections;
* '''FC-1''' – Transmission Protocol, which implements line coding of signals;
* '''FC-0''' – [[Physical layer|physical layer]], includes cabling, connectors etc.;
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.

==Ports==
[[File:Fibre Channel Topologies.svg|thumb|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:
* '''N_Port (Node port)''' An N_Port is typically an HBA port that connects to a switch's F_Port or another N_Port.  Nx_Port communicating through a PN_Port that is not operating a Loop Port State Machine.<ref name="FC-FS-4" />
* '''F_Port (Fabric port)''' An F_Port is a switch port that is connected to an N_Port.<ref name="FC-SW-6" />
* '''E_Port (Expansion port)''' Switch port that attaches to another E_Port to create an Inter-Switch Link.<ref name="FC-SW-6" />

Fibre Channel Loop protocols create multiple types of Loop Ports:
* '''L_Port (Loop port)''' FC_Port that contains Arbitrated Loop functions associated with the Arbitrated Loop topology.<ref name="FC-SW-6" />
* '''FL_Port (Fabric Loop port)''' L_Port that is able to perform the function of an F_Port, attached via a link to one or more NL_Ports in an Arbitrated Loop topology.<ref name="FC-SW-6" />
* '''NL_Port (Node Loop port)''' PN_Port that is operating a Loop port state machine.<ref name="FC-SW-6" />

If a port can support loop and non-loop functionality, the port is known as:
* '''Fx_Port''' switch port capable of operating as an F_Port or FL_Port.<ref name="FC-FS-4" />
* '''Nx_Port''' end point for Fibre Channel frame communication, having a distinct address identifier and Name_Identifier,providing an independent set of FC-2V functions to higher levels, and having the ability to act as an Originator, a Responder, or both.<ref name="FC-FS-4" />

[[File:Logical Port Structures.png|thumb|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:
* '''PN_Port''' entity that includes a Link_Control_Facility and one or more Nx_Ports.<ref name="FC-SW-6" />
* '''VF_Port (Virtual F_Port)''' instance of the FC-2V sublevel that connects to one or more VN_Ports.<ref name="FC-SW-6" />
* '''VN_Port (Virtual N_Port)''' instance of the FC-2V sublevel. VN_Port is used when it is desired to emphasize support for multiple Nx_Ports on a single Multiplexer (e.g., via a single PN_Port).<ref name="FC-FS-4" />
* '''VE_Port (Virtual E_Port)''' instance of the FC-2V sublevel that connects to another VE_Port or to a B_Port to create an Inter-Switch Link.<ref name="FC-SW-6" />

The following types of ports are also used in Fibre Channel:
* '''A_Port (Adjacent port)''' combination of one PA_Port and one VA_Port operating together.<ref name="FC-SW-6">Fibre Channel - Switch Fabric 6 (FC-SW-6)</ref>
* '''B_Port (Bridge Port)''' Fabric inter-element port used to connect bridge devices with E_Ports on a Switch.<ref name="FC-FS-4">Fibre Channel - Framing and Signaling - 4 (FC-FS-4)</ref>
* '''D_Port (Diagnostic Port)''' A configured port used to perform diagnostic tests on a link with another D_Port.<ref name="BCFA Nutshell" />
* '''EX_Port''' A type of E_Port used to connect to an FC router fabric.<ref name="BCFA Nutshell" />
* '''G_Port (Generic Fabric port)''' Switch port that may function either as an E_Port, A_Port, or as an F_Port.<ref name="FC-SW-6" />
* '''GL_Port (Generic Fabric Loop port)''' Switch port that may function either as an E_Port, A_Port, or as an Fx_Port.<ref name="FC-SW-6" />
* '''PE_Port''' LCF within the Fabric that attaches to another PE_Port or to a B_Port through a link.<ref name="FC-FS-4" />
* '''PF_Port''' LCF within a Fabric that attaches to a PN_Port through a link.<ref name="FC-FS-4" />
* '''TE_Port (Trunking E_Port) A trunking expansion port that''' expands the functionality of E ports to support VSAN trunking, Transport quality of service (QoS) parameters, and Fibre Channel trace (fctrace) feature.<ref>{{Cite web|url=https://www.cisco.com/c/en/us/td/docs/switches/datacenter/mds9000/sw/4_1/configuration/guides/fm_4_1/fmguide.html|title=Cisco MDS 9000 Family Fabric Manager Configuration Guide, Release 4.x|date=November 11, 2013|publisher=Cisco Systems, Inc.|access-date=June 28, 2016|url-status=live|archive-url=https://web.archive.org/web/20160821064642/https://www.cisco.com/c/en/us/td/docs/switches/datacenter/mds9000/sw/4_1/configuration/guides/fm_4_1/fmguide.html|archive-date=August 21, 2016}}</ref>
* '''U_Port''' '''(Universal port)''' A port waiting to become another port type<ref name="BCFA Nutshell">{{Cite web|url=https://www.brocade.com/content/dam/common/documents/content-types/education-study-tools/brocade-bcfa-nutshell-certification-study-tools.pdf|title=BCFA in a Nutshell Study Guide for Exam|date=February 2014|publisher=Brocade Communications, Inc.|access-date=June 28, 2016|url-status=live|archive-url=https://web.archive.org/web/20150907185312/http://www.brocade.com/content/dam/common/documents/content-types/education-study-tools/brocade-bcfa-nutshell-certification-study-tools.pdf|archive-date=September 7, 2015}}</ref>
* '''VA_Port (Virtual A_Port)''' instance of the FC-2V sublevel of Fibre Channel that connects to another VA_Port.<ref name="FC-SW-6" />
* '''VEX_Port''' VEX_Ports are no different from EX_Ports, except underlying transport is IP rather than FC.<ref name="BCFA Nutshell" />

==Media and modules==
{{Incomplete|section|legacy copper interfaces|date=November 2023}}{{Contradict section|date=November 2023}}
[[File:Fibre Channel Media and Modules.png|thumb|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|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 [[Engineering:Single-mode optical fiber|single-mode optical fiber]] as shown in the table below.  SFP modules use duplex fiber cabling with LC connectors.
[[File:SFP-DD SMT 17c.png|thumb|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.
{| class="wikitable sortable"
|-
! Fiber <br/>type
! Speed <br/>(MB/s)
! Transmitter<ref>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 [http://www.incits.org/ INCITS] {{webarchive|url=https://web.archive.org/web/20100915022630/http://www.incits.org/ |date=2010-09-15 }}.</ref>
! Medium variant
! Distance
|-
! rowspan="17" |Single-mode<br />Fiber (SMF)
| rowspan="2" |12,800
|1,310&nbsp;nm longwave light
|128GFC-PSM4
|0.5m - 0.5&nbsp;km
|-
|1,270, 1,290, 1,310 and 1,330&nbsp;nm longwave light
|128GFC-CWDM4
|0.5 m – 2&nbsp;km
|-
|6,400
|1,310&nbsp;nm longwave light
|64GFC-LW
|0.5m - 10&nbsp;km
|-
|3,200
|1,310&nbsp;nm longwave light
|3200-SM-LC-L
|0.5 m - 10&nbsp;km
|-
| rowspan="2" | 1,600
| 1,310&nbsp;nm longwave light<ref group="ITS" name="FC-PI-5 Clause 6.3">FC-PI-5 Clause 6.3</ref>
| 1600-SM-LC-L<ref group="ITS" name="FC-PI-5 Clause 8.1">FC-PI-5 Clause 8.1</ref> || 0.5 m – 10&nbsp;km
|-
| 1,490&nbsp;nm longwave light<ref group="ITS" name="FC-PI-5 Clause 6.3" />
| 1600-SM-LZ-I<ref group="ITS" name="FC-PI-5 Clause 8.1" /> || 0.5 m – 2&nbsp;km
|-
| rowspan="2" | 800
| rowspan="2" | 1,310&nbsp;nm longwave light<ref group="ITS" name="FC-PI-4 Clause 6.3">FC-PI-4 Clause 6.3</ref>
| 800-SM-LC-L<ref group="ITS" name="FC-PI-4 Clause 8.1">FC-PI-4 Clause 8.1</ref> || 2 m – 10&nbsp;km
|-
| 800-SM-LC-I<ref group="ITS" name="FC-PI-4 Clause 8.1" /> || 2 m – 1.4&nbsp;km
|-
| rowspan="3" | 400
| rowspan="3" | 1,310&nbsp;nm longwave light<ref group="ITS" name="FC-PI-4 Clause 6.3" /><ref group="ITS" name="FC-PH-2 lists 1300nm (see clause 6.1 and 8.1)">FC-PH-2 lists 1300nm (see clause 6.1 and 8.1)</ref>
|| 400-SM-LC-L<ref group="ITS" name="FC-PI clause 8.1">FC-PI clause 8.1</ref> || 2 m – 10&nbsp;km
|-
|| 400-SM-LC-M<ref group="ITS" name="FC-PI-4 Clause 8.1" /> || 2 m – 4&nbsp;km
|-
|| 400-SM-LL-I<ref group="ITS" name="FC-PH-2 clause 8.1">FC-PH-2 clause 8.1</ref> || 2 m – 2&nbsp;km
|-
| rowspan="3" | 200
| 1,550&nbsp;nm longwave light<ref group="ITS" name="FC-PI-4 Clause 11">FC-PI-4 Clause 11</ref>
| 200-SM-LL-V<ref group="ITS" name="FC-PI-4 Clause 11" /> || 2 m – 50&nbsp;km
|-
| rowspan="2" | 1,310&nbsp;nm longwave light<ref group="ITS" name="FC-PH-2 lists 1300nm (see clause 6.1 and 8.1)" /><ref group="ITS" name="FC-PI-4 Clause 6.3" />|| 200-SM-LC-L<ref group="ITS" name="FC-PI clause 8.1" /> || 2 m – 10&nbsp;km
|-
| 200-SM-LL-I<ref group="ITS" name="FC-PH-2 clause 8.1" /> || 2 m – 2&nbsp;km
|-
| rowspan="3" | 100
| 1,550&nbsp;nm longwave light<ref group="ITS" name="FC-PI-4 Clause 11" />
| 100-SM-LL-V<ref group="ITS" name="FC-PI-4 Clause 11" /> || 2 m – 50&nbsp;km
|-
| rowspan="2" | 1,310&nbsp;nm longwave light<ref group="ITS">FC-PH lists 1300nm (see clause 6.1 and 8.1)</ref><ref group="ITS" name="FC-PI-4 Clause 6.3" />
| 100-SM-LL-L<ref group="ITS" name="FC-PH Clause 8.1">FC-PH Clause 8.1</ref><br/>100-SM-LC-L<ref group="ITS" name="FC-PI clause 8.1" /> || 2 m – 10&nbsp;km
|-
| 100-SM-LL-I<ref group="ITS" name="FC-PH Clause 8.1" /> || 2 m – 2&nbsp;km
|-
! rowspan="23" |Multi-mode<br />Fiber (MMF)
|12,800
| rowspan="23" |850&nbsp;nm shortwave light<ref group="ITS">FC-PI-5 Clause 6.4</ref><ref group="ITS">FC-PI-4 Clause 6.4</ref><ref group="ITS">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)</ref>
|128GFC-SW4
|0 – 100 m
|-
|6,400
|64GFC-SW
|0 - 100m
|-
|3,200
|3200-SN
|0 – 100 m
|-
| rowspan="4" | 1,600
| 1600-M5F-SN-I<ref group="ITS" name="FC-PI-5 Clause 8.2">FC-PI-5 Clause 8.2</ref> || 0.5 m – 125 m
|-
| 1600-M5E-SN-I<ref group="ITS" name="FC-PI-5 Clause 8.2" /> || 0.5–100 m
|-
| 1600-M5-SN-S<ref group="ITS" name="FC-PI-5 Clause 8.2" /> || 0.5–35 m
|-
| 1600-M6-SN-S<ref group="ITS">FC-PI-5 Annex A</ref> || 0.5–15 m
|-
| rowspan="4" | 800
| 800-M5F-SN-I<ref group="ITS" name="FC-PI-5 Clause 8.2" /> || 0.5–190 m
|-
| 800-M5E-SN-I<ref group="ITS" name="FC-PI-4 Clause 8.2">FC-PI-4 Clause 8.2</ref> || 0.5–150 m
|-
| 800-M5-SN-S<ref group="ITS" name="FC-PI-4 Clause 8.2" /> || 0.5–50 m
|-
| 800-M6-SN-S<ref group="ITS" name="FC-PI-4 Clause 8.2" /> || 0.5–21 m
|-
| rowspan="4" | 400
| 400-M5F-SN-I<ref group="ITS" name="FC-PI-5 Clause 8.2" /> || 0.5–400 m
|-
| 400-M5E-SN-I<ref group="ITS" name="FC-PI-4 Clause 8.2" /> || 0.5–380 m
|-
| 400-M5-SN-I<ref group="ITS" name="FC-PI Clause 8.2">FC-PI Clause 8.2</ref> || 0.5–150 m
|-
| 400-M6-SN-I<ref group="ITS" name="FC-PI Clause 8.2" /> || 0.5–70 m
|-
| rowspan="3" | 200
| 200-M5E-SN-I<ref group="ITS" name="FC-PI-4 Clause 8.2" /> || 0.5–500 m
|-
| 200-M5-SN-I<ref group="ITS" name="FC-PI Clause 8.2" /> || 0.5–300 m
|-
| 200-M6-SN-I<ref group="ITS" name="FC-PI Clause 8.2" /> || 0.5–150 m
|-
| rowspan="5" | 100
| 100-M5E-SN-I<ref group="ITS">PC-PI-4 Clause 8.2</ref> || 0.5–860 m
|-
| 100-M5-SN-I<ref group="ITS" name="PC-PI Clause 8.2">PC-PI Clause 8.2</ref> || 0.5–500 m
|-
| 100-M6-SN-I<ref group="ITS" name="PC-PI Clause 8.2"/> || 0.5–300 m
|-
| 100-M5-SL-I<ref group="ITS" name="PC-PI Clause 8.2"/> || 2–500 m
|-
| 100-M6-SL-I<ref group="ITS">FC-PH Annex C and Annex E</ref> || 2–175 m
|}

{| class="wikitable sortable"
|-
! Multi-mode fiber !! Fiber diameter !! FC media designation
|-
! OM1
|| 62.5&nbsp;µm || M6
|-
! OM2
|| 50&nbsp;µm || M5
|-
! OM3
|| 50&nbsp;µm || M5E
|-
! OM4
|| 50&nbsp;µm || M5F
|-
! OM5
|| 50&nbsp;µm || N/A
|}

Modern Fibre Channel devices support [[Small form-factor pluggable transceiver|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==
[[File:Fibre Channel Storage Area Network.png|thumb|The Fibre Channel SAN connects servers to storage via Fibre Channel switches.]]
The goal of Fibre Channel is to create a [[Storage area network|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, [[Engineering:Tape library|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.

==Switches==
[[File:Fibre Channel Director.jpg|thumb|301x301px|Fibre Channel director with SFP+ modules and LC optical fiber connectors with Optical M<nowiki/>ultimode 3 (OM3)  fiber (aqua<nowiki/>)]]
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:

* '''Directors''' offer a high port-count in a modular (slot-based) chassis with no single point of failure (high availability).
* '''Switches''' are typically smaller, fixed-configuration (sometimes semi-modular), less redundant devices.

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==
[[File:QLogic QLE2562 8Gb FC HBA.jpg|thumb|200px|Dual port 8Gb FC host bus adapter card]]
[[File:Qlogic qle2672-ck.jpg|thumb|200px|Dual port 16Gb FC host bus adapter card]]
Fibre Channel [[Engineering:Host adapter|HBA]]s, as well as [[Converged network adapter|CNA]]s, are available for all major [[Open system (computing)|open systems]], computer architectures, and buses, including [[Engineering:Peripheral Component Interconnect|PCI]] and [[Engineering:SBus|SBus]]. 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 [[Byte|byte]]s). 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.

==See also==
{{div col|colwidth=25em}}
* [[Arbitrated loop]]
* 8b/10b encoding, 64b/66b encoding
* [[Converged network adapter]] (CNA)
* Fibre Channel electrical interface
* Fibre Channel fabric
** [[Fabric Application Interface Standard]]
** Fabric Shortest Path First – routing algorithm
** Fibre Channel zoning
** Registered State Change Notification
** Virtual Storage Area Network
* [[Fibre Channel frame]]
* Fibre Channel Logins (FLOGI)
* [[Fibre Channel network protocols]]
* Fibre Channel over Ethernet (FCoE)
* [[Fibre Channel over IP]] (FCIP), contrast with [[Internet Fibre Channel Protocol]] (iFCP)
* Fibre Channel switch
* Fibre Channel time-out values
* [[Gen 5 Fibre Channel]]
* Host Bus Adapter (HBA)
* [[Engineering:Interconnect bottleneck|Interconnect bottleneck]]
* FATA, IDE, ATA, [[Engineering:SATA|SATA]], [[Engineering:Serial Attached SCSI|SAS]], [[ATA over Ethernet|AoE]], [[Engineering:SCSI|SCSI]], [[ISCSI|iSCSI]], [[Engineering:PCI Express|PCI Express]]
* [[IPFC|IP over Fibre Channel]] (IPFC)
* [[List of Fibre Channel standards]]
* List of device bandwidths
* N Port ID Virtualization
* [[Engineering:Optical communication|Optical communication]]
* [[Engineering:Optical fiber cable|Optical fiber cable]]
* [[Engineering:Parallel optical interface|Parallel optical interface]]
* [[Serial Storage Architecture]] (SSA)
* [[Storage area network|Storage Area Network]]
* Storage Hypervisor
* [[World Wide Name]]
{{Div col end}}

==References==
{{Reflist|30em}}

===INCITS standards===
{{Reflist|group=ITS}}

==Sources==
* Clark, T. ''Designing Storage Area Networks'', Addison-Wesley, 1999. {{ISBN|0-201-61584-3}}

==Further reading==
* {{IETF RFC|2625}} – IP and ARP over Fibre Channel
* {{IETF RFC|2837}} – Definitions of Managed Objects for the Fabric Element in Fibre Channel Standard
* {{IETF RFC|3723}} – Securing Block Storage Protocols over IP
* {{IETF RFC|4044}} – Fibre Channel Management [[Management information base|MIB]]
* {{IETF RFC|4625}} – Fibre Channel Routing Information MIB
* {{IETF RFC|4626}} – MIB for Fibre Channel's Fabric Shortest Path First (FSPF) Protocol

== External links ==
<!-- ATTENTION! Please do not add links without discussion and consensus on the talk page. Undiscussed links will be removed. -->
* [http://www.fibrechannel.org/ Fibre Channel Industry Association] (FCIA)
* [http://www.t11.org/index.html INCITS technical committee responsible for FC standards(T11)]
* [http://www.redbooks.ibm.com/redbooks.nsf/0/f98c75e7c6b5a4ca88256d0c0060bcc0?OpenDocument IBM SAN Survival Guide]
* [http://www.redbooks.ibm.com/abstracts/sg245470.html?Open Introduction to Storage Area Networks]
* [http://hsi.web.cern.ch/HSI/fcs/spec/overview.htm Fibre Channel overview]
* [http://www.iol.unh.edu/training/fc/tutorials/fc_tutorial.php Fibre Channel tutorial] (UNH-IOL)
* [http://www.snia.org Storage Networking Industry Association] (SNIA)
* [http://thetechnologychronicle.blogspot.in/2013/12/virtual-fibre-channel-in-hyper-v.html Virtual fibre Channel in Hyper V]
* [https://blog.osnexus.com/2012/03/20/understanding-fc-fabric-configuration-5-paragraphs/ FC Switch Configuration Tutorial]

{{Computer-bus}}
{{Solid-state drive}}

[[Category:Computer storage buses]]

{{Sourceattribution|Fibre Channel}}