Editing Small Form-factor Pluggable

{{short description|Modular communications interface}}
{{Redirect|OSFP|the multi-sport club based in Piraeus, Greece|Olympiacos CFP}}
{{Use American English|date=March 2021}}
{{Use mdy dates|date=March 2021}}

[[file:SFP board 2.jpg|thumb|Small Form-factor Pluggable connected to a pair of [[fiber-optic cable]]s]]

'''Small Form-factor Pluggable''' ('''SFP''') is a compact, [[hot-pluggable]] network interface module format used for both [[telecommunication]] and [[data communications]] applications. An SFP interface on [[networking hardware]] is a modular slot for a media-specific [[transceiver]], such as for a [[fiber-optic cable]] or a copper cable.<ref name="pcmag"/> The advantage of using SFPs compared to fixed interfaces (e.g. [[modular connector]]s in [[Ethernet switches]]) is that individual ports can be equipped with different types of transceivers as required, with the majority including [[optical line terminal]]s, [[network card]]s, [[Network Switch|switches]] and [[Router (computing)|routers]].

The [[Form factor (design)|form factor]] and electrical interface are specified by a [[multi-source agreement]] (MSA) under the auspices of the [[Small Form Factor Committee]].<ref name="sfpmsa"/> The SFP replaced the larger [[gigabit interface converter]] (GBIC) in most applications, and has been referred to as a '''Mini-GBIC''' by some vendors.<ref name="Cisco MGBSX1"/>

SFP transceivers exist supporting [[synchronous optical networking]] (SONET), [[Gigabit Ethernet]], [[Fibre Channel]], [[Passive optical network|PON]], and other communications standards. At introduction, typical speeds were {{nowrap|1 Gbit/s}} for Ethernet SFPs and up to {{nowrap|4 Gbit/s}} for Fibre Channel SFP modules.<ref>{{cite web|url=https://www.flexoptix.net/en/transceiver/sfp-singlemode-transceiver-4g-fc-sm-1310nm-5km-10db-ddm-dom.html?co3101=18397 |title=4G Fibre Channel SFP |publisher=Flexoptix GmbH |access-date=2019-10-05}}</ref> In 2006, '''SFP+''' specification brought speeds up to {{nowrap|10 Gbit/s}} and the later '''SFP28''' iteration, introduced in 2014,<ref>{{Cite web |date=2022-12-02 |title=DRAFT SFF-8402 CB |url=https://members.snia.org/document/dl/35505 |access-date=2024-09-24 |website=SNIA Members |publisher=Storage Networking Industry Association (SNIA)}}</ref> is designed for speeds of {{nowrap|25 Gbit/s}}.<ref name="snia"/>

A slightly larger sibling is the four-lane '''Quad Small Form-factor Pluggable''' ('''QSFP'''). The additional lanes allow for speeds 4 times their corresponding SFP. In 2014, the '''QSFP28''' variant was published allowing speeds up to {{nowrap|100 Gbit/s}}.<ref name="sff-8665"/> In 2019, the closely related '''QSFP56''' was standardized<ref name="sff-8636r2.9.2draft" /> doubling the top speeds to {{nowrap|200 Gbit/s}} with products already selling from major vendors.<ref>{{Cite web|url=http://www.mellanox.com/related-docs/prod_ib_switch_systems/PB_QM8700.pdf|title=Mellanox Quantum 8700 40 port QSFP56 Product Brief}}</ref> There are inexpensive adapters allowing SFP transceivers to be placed in a QSFP port.

Both a '''SFP-DD''',<ref name="SFP-DD MSA"/> which allows for {{nowrap|100 Gbit/s}} over two lanes, as well as a '''QSFP-DD'''<ref name="QSFP-DD MSA"/> specifications, which allows for {{nowrap|400 Gbit/s}} over eight lanes, have been published.<ref name="Lightwave" /> These use a [[Form factor (design)|form factor]] which is directly [[Backward compatibility|backward compatible]] to their respective predecessors.<ref>{{cite web |title=Backward Compatibility: QSFP-DD/QSFP28/QSFP+/SFP+ |url=https://www.qsfptek.com/article/backward-compatibility-qsfp-dd-qsfp28-qsfp-sfp |publisher=Derek |access-date=21 July 2022}}</ref>

An even larger sibling, the '''Octal Small Format Pluggable''' ('''OSFP'''), had products released in 2022<ref>{{Cite web|title=Introduction - NVIDIA QM97X0 NDR SWITCH SYSTEMS USER MANUAL - NVIDIA Networking Docs|url=https://docs.nvidia.com/networking/display/QM97X0PUB/Introduction#Introduction-speeds|access-date=2022-01-18|website=docs.nvidia.com}}</ref> capable of {{nowrap|800 Gbit/s}} links between network equipment. It is a slightly larger version than the QSFP form factor allowing for larger power outputs. The OSFP standard was initially announced in 2016<ref name="OSFP MSA" /> with the 4.0 version released in 2021 allowing for {{nowrap|800 Gbit/s}} via 8×{{nowrap|100 Gbit/s}} electrical data lanes.<ref>{{Cite press release|orig-date=2021-06-03|title=OSFP MSA Announces Release of OSFP 4.0 Specification for 800G Modules|url=https://www.osfpmsa.org/press-releases/pr-20210603.html|access-date=2022-01-18|website=www.osfpmsa.org|quote=With the 800G spec completed, group is developing specification for 1600G modules}}</ref> Its proponents say a low-cost adapter will allow for backwards compatibility with QSFP modules.<ref>{{cite web|url=https://osfpmsa.org/assets/pdf/OSFP-to-QSFP-Adapter.pdf|title=OSFP to QSFP Adapter |access-date=2021-11-02}}</ref>

==SFP types==
SFP transceivers are available with a variety of transmitter and receiver specifications, allowing users to select the appropriate transceiver for each link to provide the required ''optical'' or ''electrical reach'' over the available media type (e.g. [[twisted pair]] or [[Twinaxial cabling|twinaxial]] copper cables, [[multi-mode]] or [[single-mode]] fiber cables). Transceivers are also designated by their transmission speed. SFP modules are commonly available in several different categories.

{| class="wikitable" style="text-align:center;"
|+ Comparison of SFP types
|-
! Name
! Nominal <br/>speed
! Lanes
! Standard
! Introduced 
! Backward-compatible
! [[PHY#Ethernet physical transceiver|PHY]] interface
! Connector
|- 
| align="left" | SFP
| {{nowrap|100 Mbit/s}} 
| 1
| [[Small Form Factor Committee|SFF]] INF-8074i
| 2001-05-01
| {{n/a|None}}
| MII
| LC, RJ45
|-
| align="left" | SFP
| {{nowrap|1 Gbit/s}} 
| 1
| [[Small Form Factor Committee|SFF]] INF-8074i
| 2001-05-01
| {{nowrap|100 Mbit/s}} SFP*
| SGMII
| LC, RJ45
|-
| align="left" | cSFP
| {{nowrap|1 Gbit/s}} 
| 2
|
| 
| 
| 
| LC 
|-
| align="left" |SFP+
| {{nowrap|10 Gbit/s}} 
| 1
| [[Small Form Factor Committee|SFF]] SFF-8431 4.1
| 2009-07-06
| SFP
| XGMII
| LC, RJ45
|-
| align="left" | SFP28
| {{nowrap|25 Gbit/s}} 
| 1
| [[Small Form Factor Committee|SFF]] SFF-8402
| 2014-09-13
| SFP, SFP+
| 
| LC
|-
| align="left" | SFP56
| {{nowrap|50 Gbit/s}} 
| 1
|
| 
| SFP, SFP+, SFP28
| 
| LC 
|-
| align="left" | SFP-DD
| {{nowrap|100 Gbit/s}}
| 2
| rowspan="3" | SFP-DD MSA<ref name=sfp-dd.spec/>
| 2018-01-26
| SFP, SFP+, SFP28, SFP56
| 
| LC 
|-
| align="left" | SFP112
| {{nowrap|100 Gbit/s}} 
| 1
| 2018-01-26
| SFP, SFP+, SFP28, SFP56
| 
| LC 
|-
| align="left" | SFP-DD112
| {{nowrap|200 Gbit/s}} 
| 2
| 2018-01-26
| SFP, SFP+, SFP28, SFP56, SFP-DD, SFP112
| 
| LC 
|-
! colspan="8" | QSFP types
|-
| align="left" | QSFP
| {{nowrap|4 Gbit/s}}
| 4
| [[Small Form Factor Committee|SFF]] INF-8438
| 2006-11-01
| {{n/a|None}}
| GMII
|
|-
| align="left" | QSFP+
| {{nowrap|40 Gbit/s}} 
| 4
| [[Small Form Factor Committee|SFF]] SFF-8436
| 2012-04-01
| {{n/a|None}}
| XGMII
| LC, MTP/MPO
|-
| align="left" | QSFP28
| {{nowrap|50 Gbit/s}}
| 2
| [[Small Form Factor Committee|SFF]] SFF-8665 
| 2014-09-13
| QSFP+
| 
| LC 
|-
| align="left" | QSFP28
| {{nowrap|100 Gbit/s}}
| 4
| [[Small Form Factor Committee|SFF]] SFF-8665 
| 2014-09-13
| QSFP+
| 
| LC, {{nowrap|MTP/MPO-12}}
|-
| align="left" | QSFP56
| {{nowrap|200 Gbit/s}} 
| 4
| [[Small Form Factor Committee|SFF]] SFF-8665 
| 2015-06-29
| QSFP+, QSFP28
| 
| LC, {{nowrap|MTP/MPO-12}}
|-
| align="left" | QSFP112
| {{nowrap|400 Gbit/s}} 
| 4
| [[Small Form Factor Committee|SFF]] SFF-8665 
| 2015-06-29
| QSFP+, QSFP28, QSFP56
| 
| LC, {{nowrap|MTP/MPO-12}}
|-
| align="left" | QSFP-DD
| {{nowrap|400 Gbit/s}} 
| 8
| [[Small Form Factor Committee|SFF]] INF-8628
| 2016-06-27
| QSFP+, QSFP28,<ref name="Cisco-400G_QSFP-DD">{{cite web |title=Cisco 400G QSFP-DD Cable and Transceiver Modules Data Sheet |url=https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/datasheet-c78-743172.html |website=Cisco |access-date=2020-03-27 |language=en}}</ref> QSFP56
| 
| LC, {{nowrap|MTP/MPO-16}}
|}

Note that the QSFP/QSFP+/QSFP28/QSFP56 are designed to be electrically backward compatible with SFP/SFP+/SFP28 or SFP56 respectively. Using a simple adapter or a special direct attached cable it is possible to connect those interfaces together using just one lane instead of four provided by the QSFP/QSFP+/QSFP28/QSFP56 form factor. The same applies to the QSFP-DD form factor with 8 lanes which can work downgraded to 4/2/1 lanes.

=== {{nowrap|100 Mbit/s}} SFP ===
<!--Information below would probably be better presented as a table-->
<!--https://members.snia.org/document/dl/26184-->

* Multi-mode fiber, [[LC connector]], with '''{{fontcolour|black|#f1f5fc|black}}''' or '''{{fontcolour|#CCCC00|#f1f5fc|Beige}}''' color coding
** '''SX'''{{snd}}850&nbsp;nm, for a maximum of 550&nbsp;m 
* Multi-mode fiber, [[LC connector]], with '''{{fontcolour|blue|#f1f5fc|blue}}''' color coding
** '''[[Fast Ethernet#100BASE-FX|FX]]'''  {{snd}}1300&nbsp;nm, for a distance up to 5&nbsp;km. 
** '''[[Fast Ethernet#100BASE-LFX|LFX]]''' (name dependent on manufacturer){{snd}}1310&nbsp;nm, for a distance up to 5&nbsp;km.
* Single-mode fiber, LC connector, with '''{{fontcolour|blue|#f1f5fc|blue}}''' color coding
** '''[[Fast Ethernet#100BASE-LX|LX]]'''{{snd}}1310&nbsp;nm, for distances up to 10&nbsp;km 
** '''[[Fast Ethernet#100BASE-EX|EX]]'''{{snd}}1310&nbsp;nm, for distances up to 40&nbsp;km
* Single-mode fiber, LC connector, with '''{{fontcolour|green|#f1f5fc|green}}''' color coding
** '''[[Fast Ethernet#100BASE-ZX|ZX]]'''{{snd}}1550&nbsp;nm, for distances up to 80&nbsp;km, (depending on fiber path loss)
** '''EZX'''{{snd}}1550&nbsp;nm, for distances up to 160&nbsp;km (depending on fiber path loss)
* Single-mode fiber, LC connector, Bi-Directional, with '''{{fontcolour|blue|#f1f5fc|blue}}''' and '''{{fontcolour|#CCCC00|#f1f5fc|yellow}}'''  color coding
** '''BX''' (officially '''BX10'''){{snd}}1550&nbsp;nm/1310&nbsp;nm, Single Fiber Bi-Directional 100 Mbit SFP Transceivers, paired as '''BX-U''' ({{fontcolour|blue|#f1f5fc|blue}}) and '''BX-D''' ({{fontcolour|#CCCC00|#f1f5fc|yellow}}) for uplink and downlink respectively, also for distances up to 10&nbsp;km. Variations of bidirectional SFPs are also manufactured which higher transmit power versions with link length capabilities up to 40&nbsp;km.
* Copper twisted-pair cabling, [[RJ45 (telecommunications)|8P8C]] (RJ-45) connector
** [[100BASE-TX]]{{snd}} for distances up to 100m.

=== {{nowrap|1 Gbit/s}} SFP ===
<!--Information below would probably be better presented as a table-->
* 1 to 1.{{nowrap|25 Gbit/s}} multi-mode fiber, [[LC connector]], with black or beige extraction lever<ref name="sfpmsa"/>
** '''SX'''{{snd}}850&nbsp;nm, for a maximum of 550&nbsp;m at 1.{{nowrap|25 Gbit/s}} (gigabit Ethernet). Other multi-mode SFP applications support even higher rates at shorter distances.<ref>{{citation |url=http://agilestar.com/p/datasheets/FTLF8524P2BNV-AS.pdf |title=Agilestar/Finisar FTLF8524P2BNV specification}}</ref>
* 1 to 1.{{nowrap|25 Gbit/s}} multi-mode fiber, [[LC connector]], extraction lever colors not standardized
** '''SX+/MX/LSX/LX''' (name dependent on manufacturer){{snd}}1310&nbsp;nm, for a distance up to 2&nbsp;km.<ref>{{Cite web|url=https://www.cdw.com/shop/products/PROLINE-1000BASE-SX-EXT-MMF-SFP-F-CISCO-1310NM-2KM/2240353.aspx|title=PROLINE 1000BASE-SX EXT MMF SFP F/CISCO 1310NM 2KM - SFP-MX-CDW - Ethernet Transceivers|website=CDW.com|access-date=2017-01-02}}</ref> Not compatible with SX or 100BASE-FX. Based on LX but engineered to work with a multi-mode fiber using a standard multi-mode patch cable rather than a mode-conditioning cable commonly used to adapt LX to multi-mode.
* 1 to 2.{{nowrap|5 Gbit/s}} single-mode fiber, LC connector, with blue extraction lever<ref name="sfpmsa"/>
** '''LX'''{{snd}}1310&nbsp;nm, for distances up to 10&nbsp;km (originally, '''LX''' just covered 5&nbsp;km and '''LX10''' for 10&nbsp;km followed later)
** '''EX'''{{snd}}1310&nbsp;nm, for distances up to 40&nbsp;km 
** '''ZX'''{{snd}}1550&nbsp;nm, for distances up to 80&nbsp;km (depending on fiber path loss), with green extraction lever (see GLC-ZX-SM1)
** '''EZX'''{{snd}}1550&nbsp;nm, for distances up to 160&nbsp;km (depending on fiber path loss)
** '''BX''' (officially '''BX10'''){{snd}}1490&nbsp;nm/1310&nbsp;nm, Single Fiber Bi-Directional Gigabit SFP Transceivers, paired as '''BX-U''' and '''BX-D''' for uplink and downlink respectively, also for distances up to 10&nbsp;km.<ref>{{citation|title=Single Fiber Bidirectional SFP Transceiver|url=http://www.interlinkweb.com/systemics/assets/product_images/mrv/MRV-OP-SFPB_A4_HI-1.pdf|archive-url=https://web.archive.org/web/20160419114354/http://www.interlinkweb.com/systemics/assets/product_images/mrv/MRV-OP-SFPB_A4_HI-1.pdf|archive-date=2016-04-19|publisher=MRV}}</ref><ref>{{citation|url=http://yamasakiot.com/yamasaki-sfp-transceivers |title=Gigabit Bidirectional SFPs |publisher=Yamasaki Optical Technology}}</ref> Variations of bidirectional SFPs are also manufactured which use 1550&nbsp;nm in one direction, and higher transmit power versions with link length capabilities up to 80&nbsp;km.
** 1550&nbsp;nm 40&nbsp;km ('''XD'''), 80&nbsp;km ('''ZX'''), 120&nbsp;km ('''EX''' or '''EZX''')
** '''SFSW'''{{snd}}single-fiber single-wavelength transceivers, for bi-directional traffic on a single fiber. Coupled with CWDM, these double the traffic density of fiber links.<ref>{{cite web |url=http://www.lightwaveonline.com/articles/2002/09/single-fiber-single-wavelength-gigabit-transceivers-53448792.html|title=Single-fiber single-wavelength gigabit transceivers |access-date=2002-09-05 |work=Lightwave|date=September 5, 2002 }}</ref><ref>{{cite web |url=http://www.gigalight.com.cn/solutions/&FrontComContent_list01-12987118519831ContId=3878029b-493c-4e70-b97c-766776c55cd0&comContentId=3878029b-493c-4e70-b97c-766776c55cd0&comp_stats=comp-FrontComContent_list01-12987118519831.html |title=The principle of Single Wavelength BiDi Transceiver |publisher=Gigalight |url-status=dead |archive-url=https://web.archive.org/web/20140403232845/http://www.gigalight.com.cn/solutions/%26FrontComContent_list01-12987118519831ContId%3D3878029b-493c-4e70-b97c-766776c55cd0%26comContentId%3D3878029b-493c-4e70-b97c-766776c55cd0%26comp_stats%3Dcomp-FrontComContent_list01-12987118519831.html |archive-date=2014-04-03 |df=mdy-all }}</ref>
** [[Coarse wavelength-division multiplexing]] (CWDM) and [[dense wavelength-division multiplexing]] (DWDM) transceivers at various wavelengths achieve various maximum distances. CWDM and DWDM transceivers usually support link distances of 40, 80 and 120&nbsp;km.
* {{nowrap|1 Gbit/s}} for copper twisted-pair cabling, [[RJ45 (telecommunications)|8P8C]] (RJ-45) connector
** [[1000BASE-T]]{{snd}}these modules incorporate significant interface circuitry for [[Physical Coding Sublayer]] recoding<ref>{{citation |url=http://www.vitesse.com/products/download.php?fid=295&number=VSC8211 |title=VSC8211 media converter/physical layer specification}}</ref> and can be used only for [[gigabit Ethernet]] because of the specific line code. They are not compatible with (or rather: do not have equivalents for) [[Fibre Channel]] or SONET. Unlike most non-SFP, copper 1000BASE-T ports integrated into most routers and switches, 1000BASE-T SFPs usually cannot operate at [[100BASE-TX]] speeds.
* {{nowrap|100 Mbit/s}} copper and optical{{snd}}some vendors have shipped {{nowrap|100 Mbit/s}} limited SFPs for [[fiber-to-the-home]] applications and drop-in replacement of legacy [[100BASE-FX]] circuits. These are relatively uncommon and can be easily confused with {{nowrap|100 Mbit/s}} SFPs.<ref>{{Cite web|url=http://www.fs.com/c/100base-sfp_1668|title=Fiberstore: 100&nbsp;M SFPs}}</ref>
* Although it is not mentioned in any official specification document the maximum data rate of the original SFP standard is {{nowrap|5 Gbit/s}}.<ref>{{cite web|url=http://www.siemon.com/sis/application-guide/2010-08-20-FAQs-for-SFP-plus.asp |title=FAQs for SFP+ |publisher=The Siemon Company |date=2010-08-20 |access-date=2016-02-22}}</ref> This was eventually used by both 4GFC Fibre Channel and the DDR Infiniband especially in its four-lane QSFP form.
*In recent years,{{when|date=January 2020}} SFP transceivers have been created that will allow [[2.5GBASE-T and 5GBASE-T|2.{{nowrap|5 Gbit/s}} and {{nowrap|5 Gbit/s}} Ethernet]] speeds with SFPs with 2.5GBASE-T<ref>{{cite web|url=https://www.flexoptix.net/en/transceiver/sfp-t-transceiver-2h-gigabit-cat-5e-rj-45-100m-100m-1000m-2500-base-t.html?co8829=85744 |title=2.5GBASE-T Copper SFP |publisher=Flexoptix GmbH |access-date=2019-10-04}}</ref> and 5GBASE-T.<ref>{{cite web|url=https://www.flexoptix.net/en/transceiver/sfp-t-transceiver-5-gigabit-cat-5e-rj-45-70m-100m-1000m-5gbase-t.html?co8831=85745|title=5GBASE-T Copper SFP|publisher=Flexoptix GmbH|access-date=2019-10-04}}</ref>

==={{anchor|SFP+}}{{nowrap|10 Gbit/s}} SFP+<!--[[Enhanced small form-factor pluggable transceiver]] redirects here-->===
[[File:10_Gbit_XFP_and_SFP_transceivers.jpg|thumb|350px|right|A [[10 Gigabit Ethernet]] [[XFP transceiver]], ''top'', and a SFP+ transceiver, ''bottom'']]

The '''SFP+''' ('''enhanced small form-factor pluggable''') is an enhanced version of the SFP that supports data rates up to 16&nbsp;[[Gbit/s]]. The SFP+ specification was first published on May 9, 2006, and version 4.1 was published on July 6, 2009.<ref name="spec">{{cite web|url=https://members.snia.org/document/dl/25891|title=SFF-8431 Specifications for Enhanced Small Form Factor Pluggable Module SFP+ Revision 4.1|date=July 6, 2009|access-date=2023-09-25}}</ref> SFP+ supports {{nowrap|8 Gbit/s}} [[Fibre Channel]], [[10 Gigabit Ethernet]] and [[Optical Transport Network]] standard OTU2. It is a popular industry format supported by many network component vendors. Although the SFP+ standard does not include mention of {{nowrap|16 Gbit/s}} Fibre Channel, it can be used at this speed.<ref>{{cite web |url=http://www.tek.com/primer/characterizing-sfp-transceiver-16g-fibre-channel-rate|title=Characterizing an SFP+ Transceiver at the 16G Fibre Channel Rate |author=Tektronix | date= November 2013 }}</ref> Besides the data rate, the major difference between 8 and {{nowrap|16 Gbit/s}} Fibre Channel is the encoding method. The [[64b/66b encoding]] used for {{nowrap|16 Gbit/s}} is a more efficient encoding mechanism than [[8b/10b encoding|8b/10b]] used for {{nowrap|8 Gbit/s}}, and allows for the data rate to double without doubling the line rate. 16GFC doesn't really use {{nowrap|16 Gbit/s}} signaling anywhere. It uses a 14.{{nowrap|025 Gbit/s}} line rate to achieve twice the throughput of 8GFC.<ref>{{cite web
 |title       = Roadmaps
 |url         = https://fibrechannel.org/roadmap/
 |publisher   = Fibre Channel Industry Association
 |access-date  = 2023-03-05
}}</ref>

SFP+ also introduces [[10 Gigabit Ethernet#SFP+ direct attach|direct attach]] for connecting two SFP+ ports without dedicated transceivers. Direct attach cables (DAC) exist in passive (up to 7&nbsp;m), active (up to 15&nbsp;m), and active optical (AOC, up to 100&nbsp;m) variants.

{{nowrap|10 Gbit/s}} SFP+ modules are exactly the same dimensions as regular SFPs, allowing the equipment manufacturer to re-use existing physical designs for 24 and 48-port switches and modular [[line card]]s. In comparison to earlier [[XENPAK]] or [[XFP]] modules, SFP+ modules leave more circuitry to be implemented on the host board instead of inside the module.<ref>{{cite web |url= http://www.lightwaveonline.com/articles/print/volume-23/issue-4/technology/10-gigabit-ethernet-camp-eyes-sfp-53428172.html|title=10-Gigabit Ethernet camp eyes SFP+ |work=LightWave |date=April 2006 }}</ref> Through the use of an active electronic adapter, SFP+ modules may be used in older equipment with [[XENPAK]] ports <ref>{{Cite web|url=https://www.flexoptix.net/en/10-gigabit-xenpak-sfp-plus-adapter.html|title=SFP+ to XENPAK adapter}}</ref> and [[X2 transceiver|X2]] ports.<ref>{{Cite web|url=https://www.optcore.net/product/cisco-cvr-x2-sfp10g-compatible-10gbase-x2-to-sfp-converter-module/|title=10GBASE X2 to SFP+ Converter|date=December 27, 2016 }}</ref><ref>{{Cite web|url=https://unoptix.com/collections/10g-sfp|title=SFP Transceiver}}</ref>

SFP+ modules can be described as ''limiting'' or ''linear'' types; this describes the functionality of the inbuilt electronics. Limiting SFP+ modules include a signal amplifier to re-shape the (degraded) received signal whereas linear ones do not. Linear modules are mainly used with the low bandwidth standards such as [[10 Gigabit Ethernet#10GBASE-LRM|10GBASE-LRM]]; otherwise, limiting modules are preferred.<ref>{{cite web |url= http://www.lightwaveonline.com/general/the-road-to-sfp-examining-module-and-system-architectures-54884162.html |title=The road to SFP+: Examining module and system architectures |date= January 22, 2008 |author= Ryan Latchman and Bharat Tailor |work= Lightwave |access-date=2011-07-26 |archive-url=https://archive.today/20130128011127/http://www.lightwaveonline.com/articles/2008/01/the-road-to-sfp-examining-module-and-system-architectures-54884162.html |archive-date=2013-01-28 }}</ref>

=== {{nowrap|25 Gbit/s}} SFP28 ===
SFP28 is a {{nowrap|25 Gbit/s}} interface which evolved from the [[100 Gigabit Ethernet]] interface which is typically implemented with 4 by {{nowrap|25 Gbit/s}} data lanes. Identical in mechanical dimensions to SFP and SFP+, SFP28 implements one {{nowrap|28 Gbit/s}} lane<ref>{{Cite web|url=http://www.ethernetsummit.com/English/Collaterals/Proceedings/2015/20150414_H13_Neer.pdf|title=Ethernet Summit SFP28 examples}}</ref> accommodating {{nowrap|25 Gbit/s}} of data with encoding overhead.<ref>{{Cite web|url=http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/datasheet-c78-736950.html|title=Cisco SFP28 product examples}}</ref>

SFP28 modules exist supporting single-<ref>{{Cite web|url=http://global-sei.com/company/press/2016/03/prs022.html|title=SFP28 LR 1310&nbsp;nm transceivers}}</ref> or multi-mode<ref>{{Cite web|url=http://www.smartoptics.com/wp-content/uploads/2015/08/SO-SFP28-SR-R4.0.pdf|title=SFP28 850&nbsp;nm example product}}</ref> fiber connections, active optical cable<ref>{{cite web |url=https://www.mellanox.com/related-docs/prod_cables/PB_MFA2P10-Axxx_SFP25G-AOCxxM-TG_25GbE_SFP28_AOC.pdf |title=25GbE SFP28 Active Optical Cable |publisher=Mellanox |access-date=2018-10-25}}</ref> and direct attach copper.<ref>{{cite web |url=https://www.intel.com/content/dam/www/public/us/en/documents/product-briefs/ethernet-sfp28-cables-brief.pdf |title=Intel Ethernet SFP28 Twinaxial Cables |access-date=2018-10-25}}</ref><ref>{{Cite web|url=http://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/datasheet-c78-736950.pdf|title=Cisco SFP28 direct attach cables}}</ref>

===cSFP===
The '''compact small form-factor pluggable''' ('''cSFP''') is a version of SFP with the same mechanical form factor allowing two independent bidirectional channels per port. It is used primarily to increase port density and decrease fiber usage per port.<ref>{{cite web |url=http://www.lightwaveonline.com/articles/2008/02/compact-sfp-compact-sff-msa-group-forms-54884757.html |title=Compact SFP, Compact SFF MSA group forms |work=Lightwave |date=February 20, 2008 |access-date=2018-04-12}}</ref><ref>{{cite web |url=https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver-modules/product_bulletin_c25-682262.html |title=Introducing Compact Small Form-Factor Pluggable Module (Compact SFP) |publisher=[[Cisco Systems]] |access-date=2019-01-12}}</ref>

===SFP-DD===
The '''small form-factor pluggable double density''' ('''SFP-DD''') multi-source agreement is a standard published in 2019 for doubling port density. According to the SFD-DD MSA website: "Network equipment based on the SFP-DD will support legacy SFP modules and cables, and new double density products."<ref>http://sfp-dd.com/ SFP-DD MSA</ref>
SFP-DD uses two lanes to transmit.

Currently, the following speeds are defined:
* SFP112: {{val|100|u=Gbit/s}} using PAM4 on a single pair (not double density)<ref name=sfp-dd.spec>{{cite web |author=SFP-DD MSA|title=SFP-DD/SFP-DD112/SFP112 Hardware Specification for SFP112 AND SFP DOUBLE DENSITY PLUGGABLE TRANSCEIVER Revision 5.1 |url=http://sfp-dd.com/wp-content/uploads/2022/03/SFP-DDrev5.1.pdf |date=March 11, 2022}}</ref>
* SFP-DD: {{val|100|u=Gbit/s}} using PAM4 and {{val|50|u=Gbit/s}} using NRZ<ref name=sfp-dd.spec/>
* SFP-DD112: {{val|200|u=Gbit/s}} using PAM4<ref name=sfp-dd.spec/>
* QSFP112: {{val|400|u=Gbit/s}} (4 × {{val|112|u=Gbit/s}})<ref name=qsfp-dd.msa>{{cite web |last1=QSFP-DD MSA |title=QSFP-DD/QSFP-DD800/QSFP112 Hardware Specification for QSFP DOUBLE DENSITY 8X AND QSFP 4X PLUGGABLE TRANSCEIVERS Revision 6.3 |url=http://www.qsfp-dd.com/wp-content/uploads/2022/07/QSFP-DD-Hardware-Rev6.3-final.pdf |date=July 26, 2022}}</ref>
* QSFP-DD: {{val|400|u=Gbit/s}}/{{val|200|u=Gbit/s}} (8 × {{val|50|u=Gbit/s}} and 8 × {{val|25|u=Gbit/s}})<ref>SFF INF-8628</ref>
* QSFP-DD800 (formerly QSFP-DD112): {{val|800|u=Gbit/s}} (8 × {{val|112|u=Gbit/s}})<ref name=qsfp-dd.msa/>
* QSFP-DD1600 (Draft) {{val|1.6|u=Tbit/s}}<ref>{{cite web |url=http://www.qsfp-dd.com/wp-content/uploads/2024/07/QSFP-DD-Hardware-Rev7.1.pdf |title=QSFP-DD MSA |date=2024-07-25 |access-date=2024-08-15}}</ref>

== QSFP ==
[[file:QSFP-40G-SR4_Transceiver.jpg|thumb|QSFP+ 40&nbsp;Gb transceiver]]

''Quad Small Form-factor Pluggable'' (''QSFP'') transceivers are available with a variety of transmitter and receiver types, allowing users to select the appropriate transceiver for each link to provide the required ''optical reach'' over [[multi-mode fiber|multi-mode]] or [[single-mode fiber]].

; {{nowrap|4 Gbit/s}}: The original QSFP document specified four channels carrying [[Gigabit Ethernet]], 4GFC ([[FiberChannel]]), or DDR [[InfiniBand]].<ref name="inf8438">{{cite web|url=http://ftp.seagate.com/sff/INF-8438.PDF|title=QSFP Public Specification (INF-8438)|last1=SFF Committee|publisher=SFF Committee|page=12|access-date=2016-06-22}}</ref>
; {{nowrap|40 Gbit/s}} (QSFP+): QSFP+ is an evolution of QSFP to support four {{nowrap|10 Gbit/s}} channels carrying [[10 Gigabit Ethernet]], 10GFC [[FiberChannel]], or QDR [[InfiniBand]].<ref name="sff8436">{{cite web|last1=SFF Committee|title=QSFP+ 10&nbsp;Gbs 4X Pluggable Transceiver (SFF-8436)|url=http://ftp.seagate.com/sff/SFF-8436.PDF|access-date=2016-06-22|page=13}}</ref> The 4 channels can also be combined into a single [[40 Gigabit Ethernet#Connectors|40 Gigabit Ethernet]] link.
; {{nowrap|50 Gbit/s}} (QSFP14): The QSFP14 standard is designed to carry FDR [[InfiniBand]], [[Serial Attached SCSI|SAS-3]]<ref>{{cite web|last1=SFF Committee|title=QSFP+ 14&nbsp;Gb/s 4X Pluggable Transceiver Solution (QSFP14)|url=http://ftp.seagate.com/sff/SFF-8685.PDF|access-date=2016-06-22|page=5}}</ref> or 16G Fibre Channel.
; {{nowrap|100 Gbit/s}} (QSFP28): The QSFP28 standard<ref name="sff-8665" /> is designed to carry [[100 Gigabit Ethernet]], EDR [[InfiniBand]], or 32G Fibre Channel. Sometimes this transceiver type is also referred to as ''QSFP100'' or ''100G QSFP''<ref>{{Cite web |url=https://www.arista.com/assets/data/pdf/Arista100G_TC_QA.pdf |title=100G Optics and Cabling Q&A Document |website=www.arista.com |publisher=[[Arista Networks]]}}</ref> for sake of simplicity.
; {{nowrap|200 Gbit/s}} (QSFP56): QSFP56 is designed to carry [[200 Gigabit Ethernet]], HDR [[InfiniBand]], or 64G Fibre Channel. The biggest enhancement is that QSFP56 uses four-level pulse-amplitude modulation ([[PAM-4]]) instead of [[non-return-to-zero]] (NRZ). It uses the same physical specifications as QSFP28 (SFF-8665), with electrical specifications from SFF-8024<ref name="sff-8024">{{cite web|url=https://members.snia.org/document/dl/26423|title=SFF-8024: Management Interface for Cabled Environments|date=2019-02-14|publisher=SNIA SFF Committee|access-date=2019-04-04|version=4.6}}</ref> and revision 2.10a of SFF-8636.<ref name="sff-8636r2.9.2draft">{{cite web|url=https://members.snia.org/document/dl/26418|title=Management Interface for 4-lane Modules and Cables|date=2019-09-24|series=SFF-8636|publisher=SNIA SFF Committee|access-date=2019-10-11|edition=Rev 2.10a}}</ref> Sometimes this transceiver type is referred to as ''200G QSFP''<ref>{{Cite web|url=https://www.arista.com/assets/data/pdf/Datasheets/Arista-400G_Optics_FAQ.pdf|title=Arista 400G Transceivers and Cables: Q&A|website=www.arista.com|publisher=Arista Networks, Inc.|access-date=2019-04-04}}</ref> for sake of simplicity.

Switch and router manufacturers implementing QSFP+ ports in their products frequently allow for the use of a single QSFP+ port as four independent [[10 Gigabit Ethernet]] connections, greatly increasing port density. For example, a typical 24-port QSFP+ [[19-inch rack|1U]] switch would be able to service 96x10GbE connections.<ref>{{Cite web|url=http://www.cisco.com/c/en/us/products/collateral/switches/nexus-5624q-switch/datasheet-c78-733100.html|title=Cisco Nexus 5600 specifications}}</ref><ref>{{Cite web|url=https://www.finisar.com/active-optical-cables/fcbn510qe2cxx|title=Finisar 4 x 10GbE fanout QSFP}}</ref><ref>{{Cite web|url=https://www.arista.com/assets/data/pdf/40G_FAQ.pdf|title=Arista 40Gb port to 4 x 10GbE breakout}}</ref> There also exist fanout cables to adapt a single QSFP28 port to four independent [[25 Gigabit Ethernet]] SFP28 ports (QSFP28-to-4×SFP28)<ref>{{Cite web|url=http://www.prolabs.com/products/direct-attach-cables/msa_standard/QSFP28-SFP28/QSFP28-4XSFP28-DAC-3M-NC/|title=QSFP28-to-SFP28 breakout}}</ref> as well as cables to adapt a single QSFP56 port to four independent [[50 Gigabit Ethernet]] SFP56 ports (QSFP56-to-4×SFP56).<ref>{{cite web|url=https://www.te.com/usa-en/product-4-2334236-1.html|title=QSFP56 : 4-2334236-1 Pluggable I/O Cable Assemblies|website=TE Connectivity}}</ref>

==Applications==
[[Image:Brocade FES24 Front.jpg|thumb|400px|Ethernet switch with two empty SFP slots (lower left)]]

SFP sockets are found in [[Ethernet switch]]es, routers, firewalls and [[network interface card]]s. They are used in Fibre Channel [[host adapter]]s and storage equipment. Because of their low cost, low profile, and ability to provide a connection to different types of optical fiber, SFP provides such equipment with enhanced flexibility. 

SFP sockets and transceivers are also used for long-distance [[serial digital interface]] (SDI) transmission.<ref>{{Cite book |title=For Television — Serial Digital Fiber Transmission System for SMPTE 259M, SMPTE 344M, SMPTE 292 and SMPTE 424M Signals |url=https://ieeexplore.ieee.org/document/7290552 |archive-url=https://web.archive.org/web/20170903063328/http://ieeexplore.ieee.org/document/7290552/ |url-status=dead |archive-date=September 3, 2017 |access-date=2024-01-15 |doi=10.5594/SMPTE.ST297.2006 |isbn=978-1-61482-435-0 }}</ref>

==Standardization==
The SFP transceiver is not standardized by any official standards body, but rather is specified by a [[multi-source agreement]] (MSA) among competing manufacturers. The SFP was designed after the [[GBIC]] interface, and allows greater ''port density'' (number of transceivers per given area) than the GBIC, which is why SFP is also known as mini-GBIC.

However, as a practical matter, some networking equipment manufacturers engage in [[vendor lock-in]] practices whereby they deliberately break compatibility with ''generic'' SFPs by adding a check in the device's [[firmware]] that will enable only the vendor's own modules.<ref>{{cite web |url=http://www.toad.com/gnu/sysadmin/sfp-lockin.html |title=Gigabit Ethernet fiber SFP slots and lock-in |author=John Gilmore |access-date=2010-12-21}}</ref> Third-party SFP manufacturers have introduced SFPs with EEPROMs which may be programmed to match any vendor ID.<ref>{{Cite web|url=https://www.flexoptix.net/en/flexbox-series-configure-universal-transceivers.html?395=1357&co9424= |title=FLEXBOX SERIES - CONFIGURE UNIVERSAL TRANSCEIVERS |access-date=2019-09-20}}</ref>

==Color coding of SFP==

===Color coding of SFP ===
<!---{{partial|''proprietary<br /><small>(non SFF)</small>''}}--->

{| class="wikitable" style="text-align: center; "
|-
! Color
! Standard
! Media
! Wavelength
! Notes
|-
| style="background-color:Black" | <p style="color:White;">Black</p>
| INF-8074
| Multimode
| style="background-color:#C66995" | 850&nbsp;nm
|
|-
| style="background-color:Beige" | {{nowrap|Beige}}
| INF-8074
| Multimode
| style="background-color:#C66995" | 850&nbsp;nm
|
|-
| style="background-color:Black" | <p style="color:White;">Black</p>
| INF-8074
| Multimode
| style="background-color:#C66995" | 1300&nbsp;nm
|
|-
| style="background-color:Blue" | <p style="color:White;">Blue</p>
| INF-8074
| Singlemode
| style="background-color:yellow" | 1310&nbsp;nm
|
|-
| style="background-color:Red" | {{nowrap|Red}}
| {{partial|''proprietary<br /><small>(non SFF)</small>''}}
| Singlemode
| style="background-color:yellow" | 1310&nbsp;nm
| Used on 25GBASE-ER<ref>{{cite web |title=SFP28 Transceiver, 25G SFP28 Optical Transceiver Module |url=https://www.fs.com/de-en/c/25g-sfp28-transceivers-3215 |website=FS Germany |access-date=2020-03-28|language=en}}</ref>

|-
| style="background-color:Green" | {{nowrap|Green}}
| {{partial|''proprietary<br /><small>(non SFF)</small>''}}
| Singlemode
| style="background-color:yellow" | 1550&nbsp;nm
| Used on 100BASE-ZE

|-
| style="background-color:Red" | {{nowrap|Red}}
| {{partial|''proprietary<br /><small>(non SFF)</small>''}}
| Singlemode
| style="background-color:yellow" | 1550&nbsp;nm
| Used on 10GBASE-ER

|-
| style="background-color:White" | {{nowrap|White}}
| {{partial|''proprietary<br /><small>(non SFF)</small>''}}
| Singlemode
| style="background-color:yellow" | 1550&nbsp;nm
| Used on 10GBASE-ZR

|}

===Color coding of CWDM SFP <ref>{{cite web |title=Do You Know the CWDM Transceiver Color Code? {{!}} Optcore.net |date=May 31, 2018 |url=https://www.optcore.net/do-you-know-cwdm-transceiver-color-code/ |access-date=2020-03-28}}</ref> ===
<!---{{partial|''proprietary<br /><small>(non SFF)</small>''}}--->

{| class="wikitable" style="text-align: center; "
|-
! Color
! Standard
! Wavelength
! Notes

|-
| style="background-color:Grey" | {{nowrap|Grey}}
| 
| 1270&nbsp;nm
|
|-
| style="background-color:Grey" | {{nowrap|Grey}}
| 
| 1290&nbsp;nm
|
|-
| style="background-color:Grey" | {{nowrap|Grey}}
| 
| 1310&nbsp;nm
|
|-
| style="background-color:Violet" | {{nowrap|Violet}}
| 
| 1330&nbsp;nm
|
|-
| style="background-color:blue" | {{nowrap|Blue}}
| 
| 1350&nbsp;nm
|
|-
| style="background-color:Green" | {{nowrap|Green}}
| 
| 1370&nbsp;nm
|
|-
| style="background-color:Yellow" | {{nowrap|Yellow}}
| 
| 1390&nbsp;nm
|
|-
| style="background-color:Orange" | {{nowrap|Orange}}
| 
| 1410&nbsp;nm
|
|-
| style="background-color:Red" | {{nowrap|Red}}
| 
| 1430&nbsp;nm
|
|-
| style="background-color:Brown" | {{nowrap|Brown}}
| 
| 1450&nbsp;nm
|
|-
| style="background-color:Grey" | {{nowrap|Grey}}
| 
| 1470&nbsp;nm
|
|-
| style="background-color:Violet" | {{nowrap|Violet}}
| 
| 1490&nbsp;nm
|
|-
| style="background-color:Blue" | {{nowrap|Blue}}
| 
| 1510&nbsp;nm
|
|-
| style="background-color:Green" | {{nowrap|Green}}
| 
| 1530&nbsp;nm
|
|-
| style="background-color:Yellow" | {{nowrap|Yellow}}
| 
| 1550&nbsp;nm
|
|-
| style="background-color:Orange" | {{nowrap|Orange}}
| 
| 1570&nbsp;nm
|
|-
| style="background-color:Red" | {{nowrap|Red}}
| 
| 1590&nbsp;nm
|
|-
| style="background-color:Brown" | {{nowrap|Brown}}
| 
| 1610&nbsp;nm
|
|}

===Color coding of BiDi SFP ===
<!---{{partial|''proprietary<br /><small>(non SFF)</small>''}}--->

{| class="wikitable" style="text-align: center; "
|-
! Name
! Standard
! Side A Color TX
! Side A wavelength TX
! Side B Color TX
! Side B wavelength TX
! Notes
|-
| 1000BASE-BX
| 
| style="background-color:Blue" | {{nowrap|Blue}}
| 1310&nbsp;nm
| style="background-color:purple" | {{nowrap|Purple}}
| 1490&nbsp;nm
|
|-
| 1000BASE-BX
| 
| style="background-color:Blue" | {{nowrap|Blue}}
| 1310&nbsp;nm
| style="background-color:yellow" | {{nowrap|Yellow}}
| 1550&nbsp;nm
|
|-
| 10GBASE-BX <br /> 25GBASE-BX

| 
| style="background-color:Blue" | {{nowrap|Blue}}
| 1270&nbsp;nm
| style="background-color:red" | {{nowrap|Red}}
| 1330&nbsp;nm
|
|-
| 10GBASE-BX
| 
| style="background-color:White" | {{nowrap|White}}
| 1490&nbsp;nm
| style="background-color:White" | {{nowrap|White}}
| 1550&nbsp;nm
|
|}

===Color coding of QSFP ===
<!---{{partial|''proprietary<br /><small>(non SFF)</small>''}}--->

{| class="wikitable" style="text-align: center; "
|-
! Color
! Standard
! Wavelength
! Multiplexing
! Notes
|-
| style="background-color:Beige" | {{nowrap|Beige}}
| INF-8438
| style="background-color:#C66995" | 850&nbsp;nm
| No
|
|-
| style="background-color:Blue" | {{nowrap|Blue}}
| INF-8438
| style="background-color:yellow" | 1310&nbsp;nm
| No
|
|-
| style="background-color:White" | {{nowrap|White}}
| INF-8438
| style="background-color:yellow" | 1550&nbsp;nm
| No
|
|}

==Signals==
[[File:SFP-front-RX-TX.jpg|thumb|right|Front view of SFP module with integrated [[LC connector]] indicating transmission direction of the two optical connectors]]
[[File:SFP internal.jpg|thumb|Disassembled OC-3 SFP. The top, metal canister is the transmitting laser diode, the bottom, plastic canister is the receiving photo diode.]]

SFP transceivers are ''right-handed'': From their perspective, they transmit on the right and receive on the left. When looking into the optical connectors, transmission comes from the left and reception is on the right.<ref>{{cite web |url=https://www.cisco.com/c/en/us/td/docs/interfaces_modules/transceiver_modules/installation/note/78_15160.html |title=Cisco SFP and SFP+ Transceiver Module Installation Notes |publisher=[[Cisco Systems]] |access-date=2021-06-26}}</ref>

The SFP transceiver contains a [[printed circuit board]] with an [[edge connector]] with 20 pads that mate on the rear with the SFP electrical connector in the host system. The QSFP has 38 pads including 4 high-speed transmit data pairs and 4 high-speed receive data pairs.<ref name="inf8438"/><ref name="sff8436"/>

{| {{table}}

|+SFP electrical pin-out<ref name="sfpmsa"/>
|-
! Pad
! Name
! Function
|-
| 1
| VeeT
| Transmitter ground
|-
| 2
| Tx_Fault
| Transmitter fault indication
|-
| 3
| Tx_Disable
| Optical output disabled when high
|-
| 4
| SDA
| 2-wire serial interface data line (using the [[CMOS]] [[EEPROM]] protocol defined for the [[ATMEL]] AT24C01A/02/04 family<ref>INF-8074i B4</ref>)
|-
| 5
| SCL
| 2-wire serial interface clock
|-
| 6
| Mod_ABS
| Module absent, connection to VeeT or VeeR in the module indicates module presence to host
|-
| 7
| RS0
| Rate select 0
|-
| 8
| Rx_LOS
| Receiver loss of signal indication
|-
| 9
| RS1
| Rate select 1
|-
| 10
| VeeR
| Receiver ground
|-
| 11
| VeeR
| Receiver ground
|-
| 12
| RD-
| Inverted received data
|-
| 13
| RD+
| Received data
|-
| 14
| VeeR
| Receiver ground
|-
| 15
| VccR
| Receiver power (3.3&nbsp;V, max. 300&nbsp;mA)
|-
| 16
| VccT
| Transmitter power (3.3&nbsp;V, max. 300&nbsp;mA)
|-
| 17
| VeeT
| Transmitter ground
|-
| 18
| TD+
| Transmit data
|-
| 19
| TD-
| Inverted transmit data
|-
| 20
| VeeT
| Transmitter ground
|-
|}

{| {{table}}

|+QSFP electrical pin-out<ref name="inf8438"/>
|-

! Pad
! Name
! Function
|-
|1
|GND
|Ground
|-
|2
|Tx2n
|Transmitter inverted data input
|-
|3
|Tx2p
|Transmitter non-inverted data input
|-
|4
|GND
|Ground
|-
|5
|Tx4n
|Transmitter inverted data input
|-
|6
|Tx4p
|Transmitter non-inverted data input
|-
|7
|GND
|Ground
|-
|8
|ModSelL
|Module select
|-
|9
|ResetL
|Module reset
|-
|10
|Vcc-Rx
| +3.3&nbsp;V receiver power supply
|-
|11
|SCL
|Two-wire serial interface clock
|-
|12
|SDA
|Two-wire serial interface data
|-
|13
|GND
|Ground
|-
|14
|Rx3p
|Receiver non-inverted data output
|-
|15
|Rx3n
|Receiver inverted data output
|-
|16
|GND
|Ground
|-
|17
|Rx1p
|Receiver non-inverted data output
|-
|18
|Rx1n
|Receiver inverted data output
|-
|19
|GND
|Ground
|-
|20
|GND
|Ground
|-
|21
|Rx2n
|Receiver inverted data output
|-
|22
|Rx2p
|Receiver non-inverted data output
|-
|23
|GND
|Ground
|-
|24
|Rx4n
|Receiver inverted data output
|-
|25
|Rx4p
|Receiver non-inverted data output
|-
|26
|GND
|Ground
|-
|27
|ModPrsL
|Module present
|-
|28
|IntL
|Interrupt
|-
|29
|Vcc-Tx
| +3.3&nbsp;V transmitter power supply
|-
|30
|Vcc1
| +3.3&nbsp;V power supply
|-
|31
|LPMode
|Low power mode
|-
|32
|GND
|Ground
|-
|33
|Tx3p
|Transmitter non-inverted data input
|-
|34
|Tx3n
|Transmitter inverted data input
|-
|35
|GND
|Ground
|-
|36
|Tx1p
|Transmitter non-inverted data input
|-
|37
|Tx1n
|Transmitter inverted data input
|-
|38
|GND
|Ground
|}

==Mechanical dimensions==
[[Image:SFP-side.jpg|thumb|right|Side view of SFP module. Depth, the longest dimension, is {{convert|56.5|mm|abbr=on}}.]]

The physical dimensions of the SFP transceiver (and its subsequent faster variants) are narrower than the later QSFP counterparts, which allows for SFP transceivers to be placed in QSFP ports via an inexpensive adapter. Both are smaller than the [[XFP transceiver]].

{| class="wikitable"

|+Dimensions
! rowspan=2 |
! colspan=2 | SFP<ref name="sfpmsa" />
! colspan=2 | QSFP<ref name="inf8438"/>
! colspan=2 | XFP<ref name="xfpspec">{{cite web |title= INF-8077i: 10 Gigabit Small Form Factor Pluggable Module |publisher= Small Form Factor Committee |date= August 31, 2005 |url= https://ta.snia.org/kws/public/download/97/INF-8077.PDF |access-date= 2017-03-16 |archive-date= March 17, 2017 |archive-url= https://web.archive.org/web/20170317055048/https://ta.snia.org/kws/public/download/97/INF-8077.PDF |url-status= dead }}</ref>
|-
! mm !! in !! mm !! in !! mm !! in
|-
! Height
| {{convert|8.5|mm|disp=table}}
| {{convert|8.5|mm|disp=table}}
| {{convert|8.5|mm|disp=table}}
|-
! Width
| {{convert|13.4|mm|disp=table}}
| {{convert|18.35|mm|disp=table}}
| {{convert|18.35|mm|disp=table}}
|-
! Depth
| {{convert|56.5|mm|disp=table}}
| {{convert|72.4|mm|disp=table}}
| {{convert|78.0|mm|disp=table}}
|}

==EEPROM information==

The SFP MSA defines a 256-byte memory map into an EEPROM describing the transceiver's capabilities, standard interfaces, manufacturer, and other information, which is accessible over a serial [[I²C]] interface at the 8-bit address 0b1010000X (0xA0).<ref>SFF INF-8438i ''6.2.2 Management Interface Timing Specification''</ref>

==Digital diagnostics monitoring==

Modern optical SFP transceivers support standard digital diagnostics monitoring (DDM) functions.<ref>{{citation |url=https://ta.snia.org/kws/public/download/294/SFF-8472.PDF |title=SFF-8472 |date=21 November 2014 |archive-url=https://web.archive.org/web/20170317055100/https://ta.snia.org/kws/public/download/294/SFF-8472.PDF |archive-date=2017-03-17}}</ref> This feature is also known as digital optical monitoring (DOM). This capability allows monitoring of the SFP operating parameters in real time. Parameters include optical output power, optical input power, temperature, laser bias current, and transceiver supply voltage. In network equipment, this information is typically made available via [[Simple Network Management Protocol]] (SNMP). A DDM interface allows end users to display diagnostics data and alarms for optical fiber transceivers and can be used to diagnose why a transceiver is not working.

==See also==
* [[Interconnect bottleneck]]
* [[Optical communication]]
* [[Parallel optical interface]]
* [[C form-factor pluggable]]

==References==

{{Reflist|refs=
<ref name="sfpmsa">{{citation |url=https://members.snia.org/document/dl/26184 |title=INF-8074i Specification for SFP (Small Formfactor Pluggable) Transceiver |author=SFF Committee |date=2001-05-12 |access-date=2020-04-30}}</ref>
<ref name="pcmag">{{Cite web|url=https://www.pcmag.com/encyclopedia/term/64582/sfp|title=SFP Definition from PC Magazine Encyclopedia|website=www.pcmag.com|language=en|access-date=2018-05-10}}</ref>
<ref name="snia">{{cite web|url=https://members.snia.org/document/dl/25869|title=SFF-8402: SFP+ 1X 28 Gb/s Pluggable Transceiver Solution (SFP28)|date=2014-09-13|publisher=SNIA SFF Committee|access-date=26 March 2019|version=1.9}}</ref>
<ref name="Cisco MGBSX1">{{cite web|url=https://www.cisco.com/c/en/us/support/interfaces-modules/mgbsx1-gigabit-sx-mini-gbic-sfp-transceiver/model.html|title=Cisco MGBSX1 Gigabit SX Mini-GBIC SFP Transceiver|access-date=2018-03-25}}</ref>
<ref name="sff-8665">{{cite web|url=https://members.snia.org/document/dl/25963|title=SFF-8665: QSFP+ 28 Gb/s 4X Pluggable Transceiver Solution (QSFP28)|date=2015-06-29|publisher=SNIA SFF Committee|access-date=2019-03-26|version=1.9}}</ref>
<ref name="SFP-DD MSA">{{Cite web|url=http://sfp-dd.com/|title=SFP-DD MSA}}</ref>
<ref name="QSFP-DD MSA">{{Cite web|url=http://www.qsfp-dd.com/|title=QSFP-DD MSA}}</ref>
<ref name="Lightwave">{{Cite web|url=http://www.lightwaveonline.com/articles/2016/11/osfp-msa-targets-400-gbps-optical-transceiver-module.html|title=Lightwave Online news article re: 400Gb|date=November 18, 2016 }}</ref>
<ref name="OSFP MSA">{{Cite web|url=http://osfpmsa.org/|title=OSFP MSA}}</ref>
}}

== External links ==
{{commons category}}

* [https://www.snia.org/sff SNIA SFF Technology Affiliate Technical Work Group]

{{Ethernet}}
{{Use mdy dates|date=February 2012}}

[[Category:Hot-swappable transceiver]]
[[Category:Ethernet]]