Editing Gigabit Ethernet (section)

==Fiber optics==
'''1000BASE-X''' is used in industry to refer to Gigabit Ethernet transmission over fiber, where options include 1000BASE-SX, 1000BASE-LX, 1000BASE-LX10, 1000BASE-BX10 or the non-standard -EX and -ZX implementations. Included are copper variants using the same [[8b/10b]] line code. 1000BASE-X is based on the physical-layer standards developed for [[Fibre Channel]].<ref>IEEE 802.3 Clause 36.1.1</ref>

{{Fibre legend}}

{| class="wikitable" style="line-height:110%;"
|-
! Name
! Standard
! Status
! style="width: 170px;" | Media
! Connector
! <small>Transceiver<br />Module</small>
! Reach<br />in m
! <small>#<br/>{{tooltip|Media|Number of physical media (wires/fibres) needed for bidirectional traffic}}<br/>(⇆)</small>
! <small>#<br/>{{tooltip|Lambdas|Number of wavelengths used in each direction}}<br/>(→)</small>
! <small>#<br/>{{tooltip|Lanes|Number of lanes (on the wire/fibre) in each direction}}<br/>(→)</small>
! Notes
|-
| colspan="11" {{success|'''Gigabit Ethernet (GbE)''' - <small>([[Data signaling rate|Data rate]]: {{nowrap|1000 Mbit/s}} - [[Line code]]: [[8B/10B]] × [[Non-return-to-zero|NRZ]] - Line rate: 1.25&nbsp;[[GBd]] - Full-Duplex {{fontcolour|grey|(''or Half-Duplex''))}}</small>}}
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE-CX|1000BASE‑CX]]}}
| {{nowrap|802.3z-1998}}<br /><small>(CL39)</small>
| {{partial|legacy}}
| {{terminated|[[Twisted pair|TWP]]<br />shielded<br />[[balanced]]}}<br />(150&nbsp;Ω)
| {{terminated|<small>[[Modular connector#8P8C (8 position 8 contact)|8P8C]]<br />[[D-subminiature|DE-9]]<br/>[[Fibre Channel electrical interface#8-pin "HSSDC" cable connector (High Speed Serial Data Connection)|FC/HSSDC]]<br />{{nowrap|CX4 (SFF-8470)}}<br />{{nowrap|(IEC 61076-3-103)}}</small>}}
| {{N/A}}
| style="text-align:right;" | 25
| style="text-align:right;" | 4
| style="text-align:right;" | N/A
| style="text-align:right;" | 4
| <small>[[Data center|Data centres]];<br />predates 1000BASE-T; rarely used.</small>
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE-KX|1000BASE‑KX]]}}
| {{nowrap|802.3ap-2007}}<br /><small>(CL70)</small>
| {{active|current}}
| {{terminated|Cu-[[Backplane]]}}
| {{N/A}}
| {{N/A}}
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| style="text-align:right;" | N/A
| style="text-align:right;" | 4
| <small>[[Printed circuit board|PCBs]]</small>
|-
| rowspan="3" | {{nowrap|[[Gigabit Ethernet#1000BASE‑SX|1000BASE‑SX]]}}
| rowspan="3" | {{nowrap|802.3z-1998}}<br /><small>(CL38)</small>
| rowspan="3" {{active|current}}
| rowspan="3" {{CGuest|Fibre<br /><small>'''{{fontcolour|red|770 – 860&nbsp;nm}}'''</small>}}
| rowspan="3" {{CGuest|ST<br />SC<br />LC<br />MT-RJ <ref name="MTRJ_1GbE_TCVR">{{cite web |url=http://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Data+Sheet%7F1654843%7F1103%7Fpdf%7FEnglish%7FENG_DS_1654843_1103.pdf |title=Gigabit Ethernet Multimode SFP MT-RJ Transceiver |publisher=tyco Electronics |date=November 1, 2003 |access-date=August 26, 2018}}</ref>}}
| rowspan="3" align="center" | <small>'''SFP'''<br />''<del>[[GBIC]]</del>''<br />''direct-plug''</small>
| style="background-color:orange" | {{nowrap|OM1: 275}}
| rowspan="3" align="right" | 2
| rowspan="3" align="right" | 1
| rowspan="3" align="right" | 1
| rowspan="3" |
|-
| style="background-color:orange" | {{nowrap|OM2: 550}}
|-
| style="background-color:#7DF9FF" | {{nowrap|OM3: 1k <ref name="corning multimode 2012">{{cite web |url=https://www.corning.com/catalog/coc/documents/application-engineering-notes/AEN075.pdf |title=Multimode Optical Fiber Selection & Specification |publisher=Corning Cable Systems LLC |date=2012 |access-date=23 December 2022}}</ref>}}
|-
| rowspan="3" | {{nowrap|[[Gigabit Ethernet#1000BASE‑LSX|1000BASE‑LSX]]}}
| rowspan="3" {{partial|''proprietary<br /><small>(non IEEE)</small>''}}
| rowspan="3" {{active|current}}
| rowspan="3" {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1310&nbsp;nm}}'''</small>}}
| rowspan="3" {{CGuest|LC}}
| rowspan="3" align="center" | <small>'''SFP'''</small>
| style="background-color:orange" | {{nowrap|OM1: 2k <ref>{{cite web |url=https://www.moxa.com/getmedia/ea25d5b9-e1dd-4c78-9196-75888e1df95f/moxa-sfp-1g-series-datasheet-v1.0.pdf |title=Datasheet for SFP-1G Series |publisher=MOXA  |date=October 12, 2018 |access-date=March 21, 2020}}</ref>}}
| rowspan="3" align="right" | 2
| rowspan="3" align="right" | 1
| rowspan="3" align="right" | 1
| rowspan="3" | <small>vendor-specific;<br />FP laser transmitter</small>
|-
| style="background-color:orange" | {{nowrap|OM2: 1k <ref>{{cite web |url=https://www.moxa.com/getmedia/ea25d5b9-e1dd-4c78-9196-75888e1df95f/moxa-sfp-1g-series-datasheet-v1.0.pdf |title=Datasheet for SFP-1G Series |publisher=MOXA  |date=October 12, 2018 |access-date=March 21, 2020}}</ref>}}
|-
| style="background-color:#C66995" | {{nowrap|OM4: 2k <ref>{{cite web |url=https://www.fs.com/products/75795.html |title=SFP1G-SX-31 |publisher=FS.com  |date=January 1, 2019 |access-date=March 21, 2020}}</ref>}}
|-
| rowspan="4" | {{nowrap|[[Gigabit Ethernet#1000BASE‑LX|1000BASE‑LX]]}}
| rowspan="4" | {{nowrap|802.3z-1998}}<br /><small>(CL38)</small>
| rowspan="4" {{active|current}}
| rowspan="4" {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1270 – 1355&nbsp;nm}}'''</small>}}
| rowspan="4" {{CGuest|SC<br />LC}}
| rowspan="4" align="center" | <small>'''SFP'''<br />{{fontcolour|grey|''GBIC''}}<br />''direct-plug''</small>
| style="background-color:orange" | {{nowrap|OM1: 550}}
| rowspan="4" align="right" | 2
| rowspan="4" align="right" | 1
| rowspan="4" align="right" | 1
| rowspan="4" |
|-
| style="background-color:orange" | {{nowrap|OM2: 550}}
|-
| style="background-color:#7DF9FF" | {{nowrap|OM3: 550}}
|-
| style="background-color:yellow" | {{nowrap|OSx: 5k}}
|-
| rowspan="4" | {{nowrap|[[Gigabit Ethernet#1000BASE‑LX10|1000BASE‑LX10]]}}
| rowspan="5" | {{nowrap|802.3ah-2004}}<br /><small>(CL59)</small>
| rowspan="4" {{active|current}}
| rowspan="4" {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1260 – 1360&nbsp;nm}}'''</small>}}
| rowspan="5" {{CGuest|LC}}
| rowspan="5" align="center" | <small>'''SFP'''</small>
| style="background-color:orange" | {{nowrap|OM1: 550}}
| rowspan="4" align="right" | 2
| rowspan="5" align="right" | 1
| rowspan="5" align="right" | 1
| rowspan="4" | <small>identical with -LX but with increased power/sensitivity;<br />commonly simply referred to as ''-LX'' or ''-LH'' prior to 802.3ah</small>
|-
| style="background-color:orange" | {{nowrap|OM2: 550}}
|-
| style="background-color:#7DF9FF" | {{nowrap|OM3: 550}}
|-
| style="background-color:yellow" | {{nowrap|OSx: 10k}}
|-
| {{nowrap|[[1000BASE-BX10]]}}
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{nowrap|TX: {{fontcolour|#F88379|1260 – 1360&nbsp;nm}}<br />RX: {{fontcolour|#F49AC2|1480 – 1500&nbsp;nm}}}}'''</small>}}
| style="background-color:yellow" | {{nowrap|OSx: 10k}}
| style="text-align:right;" | 1
| <small>often simply referred to as ''-BX''</small>
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE‑EX|1000BASE‑EX]]}}
| {{partial|''proprietary<br /><small>(non IEEE)</small>''}}
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1310&nbsp;nm}}'''</small>}}
| {{CGuest|SC<br />LC}}
| align="center" | <small>'''SFP'''<br />{{fontcolour|grey|''GBIC''}}</small>
| style="background-color:yellow" | {{nowrap|OSx: 40k}}
| style="text-align:right;" | 2
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>vendor-specific</small>
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE-ZX|1000BASE‑ZX / ‑EZX]]}}
| {{partial|''proprietary<br /><small>(non IEEE)</small>''}} 
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{fontcolour|#F49AC2|1550&nbsp;nm}}'''</small>}}
| {{CGuest|SC<br />LC}}
| align="center" | <small>'''SFP'''<br />{{fontcolour|grey|''GBIC''}}</small>
| style="background-color:yellow" | {{nowrap|OSx: 70k}}
| style="text-align:right;" | 2
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>vendor-specific</small>
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE‑RH|1000BASE‑RHx]]}}
| {{nowrap|802.3bv-2017}}<br /><small>(CL115)</small>
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{fontcolour|orange|650&nbsp;nm}}'''</small>}}
| {{CGuest|[[Fibre optic tranceiver|FOT]]<br /><small>(PMD/MDI)</small>}}
| {{N/A}}
| style="text-align:right;" | {{nowrap|[[Plastic optical fiber|POF]]: ≤ 50}}
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>[[Automotive]], [[Industry (manufacturing)|Industry]], [[Home]]; <ref>{{cite web |url=http://www.ieee802.org/3/bv/public/Sep_2015/perezaranda_3bv_1_0915.pdf |title=1000BASE-RH PHY system simulations |publisher=IEEE 802.3bv Task Force |date=September 8, 2015 |access-date=August 25, 2018}}</ref><ref>{{cite web |url=http://www.respice-sme.eu/fileadmin/cms/downloads/KDPOF-07_Presentation_Optical_Ethernet_Automotive.pdf |title=Optical Ethernet in Automotive |publisher=Knowledge Development for POF S.L. (KDPOF) |date=July 3, 2017 |access-date=August 25, 2018 |archive-date=September 10, 2018 |archive-url=https://web.archive.org/web/20180910014611/http://www.respice-sme.eu/fileadmin/cms/downloads/KDPOF-07_Presentation_Optical_Ethernet_Automotive.pdf |url-status=dead }}</ref><br />'''Line code: [[64b/66b encoding|64b65b]] × PAM16'''<br />'''Line rate: 325&nbsp;MBd'''<br />Variants: -RHA (50&nbsp;m), -RHB (40&nbsp;m), -RHC (15&nbsp;m).</small>
|-
| {{nowrap|1000BASE-PX}}
| {{nowrap|802.3ah-2004<br />802.3bk-2013}}<br /><small>(CL60)</small>
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{nowrap|TX: {{fontcolour|#F88379|1270&nbsp;nm}}}}<br />{{nowrap|RX: {{fontcolour|#F49AC2|1577&nbsp;nm}}}}'''</small>}}
| {{CGuest|SC}}
| align="center" | <small>'''SFP'''<br />XFP</small>
| style="background-color:yellow" | {{nowrap|OSx:<br />10k – 40k}}
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>[[Passive Optical Network|EPON]]; [[FTTH]];<br />using point-to-multipoint topology.</small>
|-
| {{nowrap|[[Gigabit Ethernet#1000BASE‑CWDM|1000BASE‑CWDM]]}}<br /><ref name="Cisco-CWDM-SFP">{{cite web |title=CWDM SFP Datasheet |url=https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/cwdm-transceiver-modules/product_data_sheet09186a00801a557c.html |website=Cisco |access-date=March 22, 2020 |date=December 29, 2005 |language=en}}</ref><ref name="FS-DWDM-info">{{cite web |title=DWDM Technology And DWDM Network Overview |url=https://community.fs.com/blog/complete-analysis-on-dwdm-technology.html |website=FS.com |access-date=March 22, 2020 |language=en |date=November 28, 2016}}</ref>
| {{partial|''ITU-T G.694.2''}}
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1270 – 1610&nbsp;nm}}'''</small>}}
| {{CGuest|LC}}
| align="center" | <small>'''SFP'''</small>
| style="background-color:yellow" | {{nowrap|OSx:<br />40k – 100k}}
| style="text-align:right;" | 2
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>[[CWDM]] makes it possible to have multiple parallel channels over 2 fibers;<br />spectral bandwidth 11&nbsp;nm;<br />capable of 18 parallel channels</small>
|- 
| {{nowrap|[[Gigabit Ethernet#1000BASE‑DWDM|1000BASE‑DWDM]]}}<br /><ref name="Cisco-DWDM-SFP">{{cite web |title=DWDM-SFP Data Sheet |url=https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/dwdm-transceiver-modules/product_data_sheet0900aecd80582763.html |website=Cisco |access-date=March 22, 2020 |language=en}}</ref><ref name="FS-DWDM-info" />
| {{partial|''ITU-T G.694.1''}}
| {{active|current}}
| {{CGuest|Fibre<br /><small>'''{{fontcolour|#F88379|1528 – 1565&nbsp;nm}}'''</small>}}
| {{CGuest|LC}}
| align="center" | <small>'''SFP'''</small>
| style="background-color:yellow" | {{nowrap|OSx:<br />40k – 120k}}
| style="text-align:right;" | 2
| style="text-align:right;" | 1
| style="text-align:right;" | 1
| <small>[[DWDM]] makes it possible to have multiple parallel channels over 2 fibers;<br />spectral bandwidth 0.2&nbsp;nm;<br />capable of 45 to 160 parallel channels</small>
|-
|}

===1000BASE-SX===
1000BASE-SX is an [[optical fiber]] Gigabit Ethernet standard for operation over multi-mode fiber using a 770 to 860 [[nanometer]], [[Infrared|near infrared]] (NIR) [[light]] [[wavelength]].

The standard specifies a maximum length of 220 meters for 62.5&nbsp;μm/160&nbsp;[[Modal bandwidth|MHz×km]] [[multi-mode fiber]], 275&nbsp;m for 62.5&nbsp;μm/200&nbsp;MHz×km, 500&nbsp;m for 50&nbsp;μm/400&nbsp;MHz×km, and 550&nbsp;m for 50&nbsp;μm/500&nbsp;MHz×km multi-mode fiber.<ref>{{Cite web|url=https://kb.wisc.edu/ns/page.php?id=7829|title=Ethernet Media Standards and Distances|website=kb.wisc.edu|access-date=February 1, 2017}}</ref><ref>IEEE 802.3 ''Table 38–2—Operating range for 1000BASE-SX over each optical fiber type''</ref> Fiber optic cable manufacturers have extended the reach of 1000BASE-SX to at least 1km when used with more modern fiber optic grades such as OM3 and OM4.<ref name="corning multimode 2012" />

This standard is highly popular for intra-building links in large office buildings, co-location facilities and carrier-neutral Internet exchanges.

Optical power specifications of SX interface: Minimum output power = −9.5&nbsp;[[dBm]]. Minimum receive sensitivity = −17&nbsp;dBm.

===1000BASE-LSX===
1000BASE-LSX is a non-standard but industry accepted<ref>{{Cite web|url=https://www.moxa.com/getmedia/ea25d5b9-e1dd-4c78-9196-75888e1df95f/moxa-sfp-1g-series-datasheet-v1.0.pdf |title=Datasheet for SFP-1G Series |publisher=MOXA  |access-date=March 21, 2020}}</ref>
term to refer to Gigabit Ethernet transmission. It is very similar to 1000BASE-SX but achieves longer distances up to 2&nbsp;km over a pair of multi-mode fibers due to higher quality optics than a SX, running on 1310&nbsp;nm wavelength lasers. It  is easily confused with 1000BASE-SX or 1000BASE-LX because the use of -LX, -LX10 and -SX is ambiguous between vendors. 
The range is achieved with use of [[Fabry Perot]] laser transmitter.

===1000BASE-LX===
1000BASE-LX is an optical fiber Gigabit Ethernet standard specified in IEEE 802.3 Clause 38 which uses a long wavelength laser (1,270–1,355&nbsp;nm), and a maximum RMS spectral width of 4&nbsp;nm.

1000BASE-LX is specified to work over a distance of up to 5&nbsp;km over 10&nbsp;μm single-mode fiber.

1000BASE-LX can also run over all common types of multi-mode fiber with a maximum segment length of 550 m. For link distances greater than 300&nbsp;m, the use of a special launch conditioning patch cord may be required.<ref>{{Cite web|url=http://www.cisco.com/c/en/us/td/docs/interfaces_modules/transceiver_modules/installation/note/OL_19329.html |title=Mode-Conditioning Patch Cord Installation Note |access-date=February 14, 2009 }}</ref> This launches the laser at a precise offset from the center of the fiber which causes it to spread across the diameter of the fiber core, reducing the effect known as differential mode delay which occurs when the laser couples onto only a small number of available modes in multi-mode fiber.

===1000BASE-LX10===
1000BASE-LX10 was standardized six years after the initial gigabit fiber versions as part of the [[Ethernet in the First Mile]] task group. It is practically identical to 1000BASE-LX, but achieves longer distances up to 10&nbsp;km over a pair of single-mode fiber due to higher quality optics. Before it was standardized, 1000BASE-LX10 was essentially already in widespread use by many vendors as a proprietary extension called either 1000BASE-LX/LH or 1000BASE-LH.<ref>{{Cite web|url=http://www.cisco.com/en/US/prod/collateral/modules/ps5455/ps6577/product_data_sheet0900aecd8033f885.html |title=Cisco SFP Optics For Gigabit Ethernet Applications |access-date=June 1, 2010 |publisher=Cisco Systems}}</ref>

===1000BASE-EX===
1000BASE-EX is a non-standard but industry accepted term<ref>{{cite web |title=fs SFP1G-EX-55 |url=https://www.fs.com/de-en/products/49943.html |website=FS Germany |access-date=March 30, 2020 |language=en}}</ref> to refer to Gigabit Ethernet transmission. It is very similar to 1000BASE-LX10 but achieves longer distances up to 40&nbsp;km over a pair of single-mode fibers due to higher quality optics than a LX10, running on 1310&nbsp;nm wavelength lasers. It is sometimes referred to as LH (Long Haul), and is easily confused with 1000BASE-LX10 or 1000BASE-ZX because the use of -LX(10), -LH, -EX, and -ZX is ambiguous between vendors. [[#1000BASE-ZX|1000BASE-ZX]] is a very similar non-standard longer-reach variant that uses 1550&nbsp;nm wavelength optics.

===1000BASE-BX10===
1000BASE-BX10 is capable of up to 10&nbsp;km over a single strand of [[single-mode fiber]], with a different wavelength going in each direction. The terminals on each side of the fiber are not equal, as the one transmitting downstream (from the center of the network to the outside) uses the 1490&nbsp;nm wavelength, and the one transmitting upstream uses the 1310&nbsp;nm wavelength. This is accomplished using a passive splitter prism inside each transceiver.

Other, non-standard higher-powered single-strand optics commonly known as "BiDi" (bi-directional) utilize wavelength pairs in the 1490/1550&nbsp;nm range, and are capable of reaching distances of 20, 40 and 80&nbsp;km, or greater depending on module cost, fiber path loss, splices, connectors and patch panels. Very long reach BiDi optics may use 1510/1590&nbsp;nm wavelength pairs.

===1000BASE-ZX===
1000BASE-ZX is a non-standard but multi-vendor<ref name="FS-SFP1G-ZX-55">{{cite web |title=FS SFP1G-ZX-55 |url=https://www.fs.com/de-en/products/11776.html |website=FS Germany |access-date=March 30, 2020 |language=en}}</ref> term to refer to Gigabit Ethernet transmission using 1,550&nbsp;nm wavelength to achieve distances of at least {{Convert|70|km|mi|abbr=on}} over single-mode fiber. Some vendors specify distances up to {{Convert|120|km|mi|abbr=on}} over single-mode fiber, sometimes called 1000BASE-EZX. Ranges beyond 80&nbsp;km are highly dependent upon the path loss of the fiber in use, specifically the attenuation figure in dB per km, the number and quality of connectors/patch panels and splices located between transceivers.<ref>{{cite web|title=1.25Gbps SFP Transceiver 120km|url=http://menaranet.com/download/datasheets/SFP/187-0A031-00%20SFP%201550nm%20EZX%201GbE%20-%20Product%20Datasheet-%202%20page.pdf|publisher=Menaranet|access-date=June 21, 2014|archive-date=December 10, 2014|archive-url=https://web.archive.org/web/20141210040945/http://menaranet.com/download/datasheets/SFP/187-0A031-00%20SFP%201550nm%20EZX%201GbE%20-%20Product%20Datasheet-%202%20page.pdf|url-status=dead}}</ref>

===1000BASE‑CWDM===
1000BASE-CWDM is a non-standard but industry accepted term<ref name="Cisco-CWDM-SFP" /><ref name="FS-DWDM-info" /> to refer to Gigabit Ethernet transmission. It is very similar to 1000BASE-LX10 but achieves longer distances up 40–120&nbsp;km, and up to 18 parallel channels over a pair of single-mode fibers due to higher quality optics than LX10 and use of CWDM, running on 1270-1610&nbsp;nm wavelength lasers.

Use of CWDM requires a Mux/Demux unit at both ends of the fiber link, a CWDM MUX/DEMUX with corresponding wavelengths, and SFP with corresponding wavelengths.<ref name="FS-DWDM-info" /> is it also possible to DWDM in serie to increase number of channels.

Most uses Wavelengths: 1270&nbsp;nm, 1290&nbsp;nm, 1310&nbsp;nm, 1330&nbsp;nm, 1350&nbsp;nm, 1370&nbsp;nm, 1390&nbsp;nm, 1410&nbsp;nm, 1430&nbsp;nm, 1450&nbsp;nm, 1470&nbsp;nm, 1490&nbsp;nm, 1510&nbsp;nm, 1530&nbsp;nm, 1550&nbsp;nm, 1570&nbsp;nm, 1590&nbsp;nm and 1610&nbsp;nm

CWDM is cheaper to use than DWDM, about 1/5-1/3 of the cost.<ref>{{cite web |title=CWDM vs. DWDM： What Are the Differences？ |url=https://medium.com/@opticalfibersolutions/cwdm-vs-dwdm-what-are-the-differences-67c1c8adeccc |website=Medium.com |access-date=March 22, 2020 |language=en |date=November 30, 2017}}</ref><ref>{{cite web |title=CWDM - Cost-Effective Alternative to Expand Network Capacity |url=https://community.fs.com/blog/cwdm-cost-effective-alternative-to-expand-network-capacity.html |website=fs.com|access-date=March 22, 2020 |language=en |date=June 17, 2014}}</ref> CWDM is about 5-10 times more expensive the if you have the fiber available, then traditional  -LX/-LZ transceivers.

===1000BASE‑DWDM===
1000BASE-DWDM is a non-standard but industry accepted term<ref name="Cisco-DWDM-SFP" /><ref name="FS-DWDM-info" /> to refer to Gigabit Ethernet transmission. It is very similar to 1000BASE-LX10 but achieves longer distances up 40–120&nbsp;km, and up to 64 to 160 parallel channels over a pair of single-mode fibers due to higher quality optics than LX10 and use of DWDM, running on 1528-1565&nbsp;nm wavelength lasers.

The most used channels are  CH17-61 on Wavelength 1528.77-1563-86&nbsp;nm.

To use DWDM it is necessary to use a Mux/Demux unit on both ends of the fiber link, a DWDM MUX/DEMUX with corresponding wavelengths, and SFP with corresponding wavelengths.<ref name="FS-DWDM-info" /> is it also possible to use CWDM in series to increase the number of channels.{{cn|date=January 2021}}

===1000BASE-RH''x''===
IEEE 802.3bv-2017 defines standardizes Gigabit Ethernet over step-index [[plastic optical fiber]] (POF) using -R [[64b/66b encoding|64b/65b]] large block encoding with red light (600–700&nbsp;nm). 1000BASE-RHA is intended for home and consumer use (just clamping the bare POF), 1000BASE-RHB for industrial, and 1000BASE-RHC for automotive applications.

=== Optical interoperability ===
There may be optical interoperability with respective 1000BASE-X Ethernet interfaces on the same link.<ref name="Cisco-100BASE-X">{{cite web |title=Cisco 100BASE-X SFP for Fast Ethernet SFP Ports |url=https://www02.cp-static.com/objects/pdf/2/227/1347766271_1_network-media-converters-cisco-100base-zx-for-fast-ethernet-sfp-ports-glc-fe-100zx253d.pdf |website=cisco |access-date=March 29, 2020 |archive-date=March 29, 2020 |archive-url=https://web.archive.org/web/20200329115059/https://www02.cp-static.com/objects/pdf/2/227/1347766271_1_network-media-converters-cisco-100base-zx-for-fast-ethernet-sfp-ports-glc-fe-100zx253d.pdf |url-status=dead }}</ref> It is also possible with certain types of optics to have a mismatch in wavelength.<ref>{{cite web |title=Everything You Always Wanted to Know About Optical Networking – But Were Afraid to Ask |url=https://archive.nanog.org/sites/default/files/Steenbergen.Everything_You_Need.pdf |website=archive.nanog.org |publisher=Richard A Steenbergen |access-date=March 30, 2020}}</ref>

To achieve interoperability some criteria have to be met:<ref>{{cite web |title=Fiber incompatabilities? - Ars Technica OpenForum |url=https://arstechnica.com/civis/viewtopic.php?p=6647265&sid=1207bc662946d0bf8ff15eac6753a819#p6647265 |website=arstechnica.com |access-date=March 29, 2020 | date=June 6, 2006}}{{sps|date=May 2020}}</ref>
* [[Line encoding]]
* [[Wavelength]]{{efn|It may be possible for certain types of optics to work with a mismatch in wavelength.<ref>{{cite web |title=Everything You Always Wanted to Know About Optical Networking – But Were Afraid to Ask |url=https://archive.nanog.org/sites/default/files/Steenbergen.Everything_You_Need.pdf |website=archive.nanog.org |publisher=Richard A Steenbergen |access-date=March 30, 2020}}</ref>}}
* [[Duplex (telecommunications)|Duplex mode]]
* Media count
* Media type and dimension

1000BASE-X Ethernet is not backward compatible with [[100BASE-X]] and is not forward compatible with [[10 Gigabit Ethernet|10GBASE-X]].