INSTITUTION PROFILE / OPTICAL COMMUNICATIONS & PHOTONICS
OIF (Optical Internetworking Forum)
The industry forum where member companies agree how optical modules plug together
OIF is a membership-based industry association headquartered in California. It is neither a government agency nor an international treaty body. Its job is to write the specifications that let products from different vendors work together straight out of the box, known as Implementation Agreements (IAs), and to publish them free of charge. The coherent optical modules that link data centres, 400ZR, 800ZR and 1600ZR, are defined in OIF IAs, and so are the module specifications for co-packaged optics (CPO). This profile looks at one question only: how much influence OIF actually has over optical communications and photonics.
- OIF in 30 seconds
- What kind of body it is: the four types of influence
- What it does in optical communications and photonics
- How far its influence reaches (powers and geography)
- The companies and organisations involved
- Outlook
- Glossary, references and claim-to-source audit
1. OIF in 30 seconds
What OIF produces is not law or a national standard but an Implementation Agreement (IA) reached among its member companies. OIF itself describes an IA as a set of normative specifications for electrical, optical, mechanical, protocol and software interfaces, to be referred to when building interoperable hardware, software and systems Sourced. It has no power to enforce them. Yet for the coherent optical modules that link data centres, a new IA has appeared with each generation: 400ZR (March 2020), 800ZR (October 2024) and 1600ZR (September 2026). OIF says its ZR work played a central role in moving coherent optics out of traditional transport equipment and directly into routers and switches (this is OIF's own assessment).
2. What kind of body it is: the four types of influence
Unlike the companies in this series, the institutions that appear in our optical communications and photonics coverage do not sell optical components. What separates them is the route by which they influence the industry, and that gives four types.
3. What it does in optical communications and photonics
The table groups the IAs and current projects on OIF's lists that bear on optical interconnect inside data centres and on optical transmission. Dates follow OIF's IA list Sourced.
| Area | Main published IAs (date) | What they cover | Work in progress (September 2026) |
|---|---|---|---|
| Coherent optics (between data centres) | 400ZR, first edition (March 2020) 800ZR (October 2024) 800LR (April 2025) 1600ZR (September 2026) | 1600ZR specifies carrying 1.6T Ethernet on a single wavelength, over amplified point-to-point dense wavelength division multiplexing (DWDM) links of up to 120 km | 1600ZR+ (up to 1,000 km; 1200ZR+ up to 2,000 km) and 1600CL (for longer reaches within a campus) |
| CPO and NPO (formerly Co-Packaging, now Energy Efficient Interfaces, EEI) | CPO framework document (February 2022) 3.2Tb/s CPO module (March 2023) External laser source ELSFP, first edition (August 2023) and second edition (January 2025) 112G RTLR (October 2025) | Specifications for CPO modules, and for a replaceable laser source module that lets the laser sit outside the switch | 12.8Tb/s and 6.4Tb/s NPO modules (200G per lane), 224G RTLR, and COI, an optical interface for linking AI compute nodes |
| Electrical interfaces (CEI) | The CEI-112G family and others | Specifications for electrical signalling between chips, and between a chip and an optical module | CEI-224G (XSR, VSR, MR, LR), CEI-224G-Linear for LPO, CPO and NPO, and CEI-448G (VSR, LR) |
| Module management (CMIS) | CMIS; C-CMIS 1.5 and CMIS-LT (approved at the August 2026 meeting) | Specifications that let any vendor's switch manage optical modules such as QSFP-DD and OSFP in the same way | CMIS-APSU, which corresponds to Annex 178B of IEEE 802.3dj, and security features |
OIF does more than write IAs. It also stages interoperability demonstrations in which products from several companies are actually connected. For the European Conference on Optical Communication in September 2026 (ECOC 2026, Málaga, Spain), OIF announced that 39 member companies would take part in demonstrations covering optical systems, CEI-448G and 224G, CMIS, CPO and energy-efficient interfaces, among others Sourced.
According to its project plan, the 12.8Tb/s NPO module IA now in progress covers mechanical dimensions, electrical connections and pin assignments, requirements for the liquid-cooling thermal interface, the light source, power supply and optical connectors Sourced. In other words, OIF's IAs reach beyond agreements on electrical signals to a module's outline and its cooling conditions. For suppliers of thermal materials, connectors, encapsulants and similar parts, this means the assumptions about the dimensions and temperatures their products will face can shift each time an IA is revised.
4. How far its influence reaches (powers and geography)
| Aspect | What OIF has | What it does not have |
|---|---|---|
| Powers | The power to approve IAs by member vote and publish them free of charge. It also hosts interoperability demonstrations | Power to enforce IAs, to allow or ban the sale of products, or to fund research |
| Geography | Headquartered in the United States, but its members include companies and universities from the United States, Japan, China, Europe, Taiwan, South Korea and elsewhere | Any mechanism that writes its IAs into a particular country's laws or technical regulations |
| Decision-making | Principal members have one vote per company in elections and on technical documents. Auditing members may attend meetings but cannot speak in working groups | Voting by individuals (unlike IEEE 802.3, votes are held by companies) |
| Relations with other standards bodies | Appoints liaisons to IEEE 802.3, ITU-T SG15, the Ethernet Alliance, PCI-SIG, InfiniBand, SNIA SFF and others. Its mission explicitly includes feeding back to standards bodies worldwide | Power to override IEEE or ITU standards |
| Export controls | Has published its own view that publicly available technical information counts as "published" under the U.S. Export Administration Regulations (EAR), so no licence is needed to share it with companies on the Entity List | Power to exempt anyone from national export controls. Exceptions such as encryption technology are left to each company to judge on its own responsibility |
IAs are free and anyone can implement them, but there is no scheme that legally certifies compliance with an IA. Some specifications, such as 400ZR, become widely used; others may be published without the products ever catching on. The primary information checked for this article is OIF's website and press releases, and shipment volumes and market shares for IA-compliant products have not been published Not yet confirmed.
5. The companies and organisations involved
How OIF relates to the companies in this series
| Group | Companies (candidates for this series) | Standing in OIF (as the primary sources put it) |
|---|---|---|
| Have a board member or officer | Broadcom, Ciena, Nokia, Cisco | Broadcom holds a board seat and the vice-chair of the Technical Committee; Ciena, Nokia and Cisco hold board seats |
| Listed as principal members | NVIDIA, Marvell, Lumentum, Coherent, Eoptolink, GlobalFoundries, AMD, Credo, Lightmatter, Ayar Labs, NTT, Sumitomo Electric Industries, Furukawa Electric, Fujikura, Mitsubishi Electric, Corning | Named under "Principal Members" in the member list (Credo appears as Credo Semiconductor (HK) and AMD as Advanced Micro Devices) |
| Not found in the member list | InnoLight, Intel, TSMC, Celestial AI, Tower Semiconductor, Fujitsu (under that name) | Not named in the member list as checked in September 2026 (Fujitsu does not appear by name, but 1FINITY is listed as a principal member) |
Note: being a member does not mean a company is closely involved in writing IAs. The public information checked for this article does not show which companies contributed to each IA. The grouping is our own, made by checking against the member list Our calculation.
6. Outlook
| What the evidence suggests | Primary information it rests on | Category |
|---|---|---|
| For 1.6T coherent links between data centres too, the market will move towards interoperable modules from several vendors | The 1600ZR IA was published in September 2026, and OIF says it was developed through the same process as 400ZR and 800ZR. Multivendor ZR interoperability is being demonstrated at ECOC 2026 | Inference |
| The next focus of standardisation after CPO will shift to NPO and optical I/O between AI compute nodes | OIF's current projects include a 12.8Tb/s NPO module and COI, an optical interface for PCIe, NVLink and UALink | Inference |
| The division of labour in which OIF fills in what IEEE 802.3 leaves out, such as module management, will continue | CMIS-APSU is described as a specification for managing Annex 178B of IEEE 802.3dj. OIF has a liaison to IEEE 802.3 | Inference |
7. Glossary
- IA (Implementation Agreement)
- OIF's output: a normative interface specification that lets products from different vendors work together. It is not legally binding.
- ZR / LR
- Labels for the reach class of an optical module. OIF's 1600ZR is intended for links of up to 120 km between data centres.
- CPO / NPO
- Co-packaged optics, which puts the optical components in the same package as the switch chip (photonic-electronic convergence), and near-packaged optics, which places them close to it.
- ELSFP
- A specification for placing the laser source used with CPO outside the switch as a replaceable module.
- CMIS
- A specification that lets host equipment manage, diagnose and update the firmware of optical modules in a common way.
8. References
- OIF About OIF: more than 25 years of activity, IAs published free of charge, more than 180 member companies. https://www.oiforum.com/about-oif/
- OIF Member Companies: lists of principal, auditing and academic members. https://www.oiforum.com/about-oif/member-companies/
- OIF Board of Directors and Officers: board members and officers, their companies and the headquarters location. https://www.oiforum.com/about-oif/board-of-directors-and-officers/
- OIF Become an OIF Member: membership categories, annual fees, one vote per principal member, and the limits on auditing members. https://www.oiforum.com/become-an-oif-member/
- OIF Implementation Agreements: definition of an IA, and the list of IAs including ZR, CPO, ELSFP and RTLR with their publication dates. https://www.oiforum.com/technical-work/implementation-agreements-ias/
- OIF Current OIF Work: current projects including CEI-224G and 448G, CMIS, NPO, COI, 1600ZR+ and 1600CL. https://www.oiforum.com/technical-work/current-work/
- OIF Press release, "OIF Releases Critical 1600ZR Coherent Interface IA" (9 September 2026): 1.6T on a single wavelength, up to 120 km, the history of the ZR work, and the ECOC 2026 demonstrations. https://www.oiforum.com/oif-releases-critical-1600zr-coherent-interface-ia-doubling-capacity-per-wavelength-for-data-center-interconnects/
- OIF Press release, "OIF Closes Q3 Member Meeting with Critical Implementation Agreements" (2 September 2026): approval of CMIS-LT and C-CMIS 1.5, and 39 companies demonstrating at ECOC 2026. https://www.oiforum.com/oif-closes-q3-member-meeting-with-critical-implementation-agreements-for-high-speed-networks/
- OIF OIF Legal: statement on dealings with companies on the Entity List. https://www.oiforum.com/about-oif/oif-legal/
- OIF Liaisons: liaisons to IEEE 802.3, ITU-T SG15 and other bodies. https://www.oiforum.com/technical-work/liaisons/
- OIF OIF Mission: the scope of IAs, interoperability testing, and feedback to standards bodies worldwide. https://www.oiforum.com/about-oif/board-of-directors-and-officers/oif-mission/
- OIF Press release, "OIF CEI Technology for 56 Gbps Available for Wider Industry Adoption" (16 January 2018): states that OIF was launched in 1998. https://www.oiforum.com/oif-cei-technology-for-56-gbps-available-for-wider-industry-adoption/
9. Claim-to-source audit
| Claim in the article | Category | Source |
|---|---|---|
| More than 25 years of activity, IAs published free of charge, more than 180 member companies | Sourced | Reference 1 https://www.oiforum.com/about-oif/ |
| Whether companies that are candidates for this series appear in the member list | Sourced | Reference 2 https://www.oiforum.com/about-oif/member-companies/ |
| Companies of board members and officers; headquarters in Fremont, California | Sourced | Reference 3 https://www.oiforum.com/about-oif/board-of-directors-and-officers/ |
| Membership categories and annual fees, one vote per principal member, auditing members unable to speak in working groups | Sourced | Reference 4 https://www.oiforum.com/become-an-oif-member/ |
| Definition of an IA; publication dates of 400ZR, 800ZR, 800LR, 1600ZR, CPO, ELSFP and RTLR | Sourced | Reference 5 https://www.oiforum.com/technical-work/implementation-agreements-ias/ |
| Current projects (NPO liquid cooling and optical connectors, COI, CEI-448G, CMIS-APSU, 1600ZR+ reach) | Sourced | Reference 6 https://www.oiforum.com/technical-work/current-work/ |
| What 1600ZR covers, and OIF's account of the history of its ZR work | Sourced | Reference 7 https://www.oiforum.com/oif-releases-critical-1600zr-coherent-interface-ia-doubling-capacity-per-wavelength-for-data-center-interconnects/ |
| Approval of CMIS-LT and C-CMIS 1.5; 39 companies demonstrating at ECOC 2026 | Sourced | Reference 8 https://www.oiforum.com/oif-closes-q3-member-meeting-with-critical-implementation-agreements-for-high-speed-networks/ |
| OIF's view on the Export Administration Regulations | Sourced | Reference 9 https://www.oiforum.com/about-oif/oif-legal/ |
| Liaisons to IEEE 802.3, ITU-T SG15 and others | Sourced | Reference 10 https://www.oiforum.com/technical-work/liaisons/ |
| Feedback to standards bodies worldwide stated as part of its mission | Sourced | Reference 11 https://www.oiforum.com/about-oif/board-of-directors-and-officers/oif-mission/ |
| Launched in 1998 | Sourced | Reference 12 https://www.oiforum.com/oif-cei-technology-for-56-gbps-available-for-wider-industry-adoption/ |
| The four types of institution, and the grouping of companies in this series | Our calculation | Our own classification |
| Shipment volumes and market shares for IA-compliant products | Not yet confirmed | Not stated in references 1 to 12; this article does not estimate them |
| The three points in the outlook (section 6) | Inference | This article's reading of references 5 to 8 and 10 |
Last updated 26 September 2026 / Troy Technical
All figures and statements come from OIF's website and press releases. Items marked "Inference" are this article's reading of the primary information, not statements by OIF.