AI Infrastructure 2026 Essentials: From LPO to OCI, a Guide to 11 Key Optical Communication MSAs and De Facto Standards
Updated: Oct 7
What is an MSA? An MSA (Multi-Source Agreement) is an agreement signed jointly by multiple manufacturers. It defines a product's physical form factor, electrical interface, optical parameters and management interface. An MSA is not an official standards body like IEEE or ITU-T, but it is the "de facto standard" the industry forms on its own to get technology deployed quickly. Why do we need MSAs? Without them, the optical communications market would descend into chaos. Here are the three core reasons MSAs exist:
1. Ensuring interoperability This is the single most important value of an MSA.
Plug and play: A switch made by Company A can take an optical module made by Company B and connect to cables from Company C.
Standardized specs: Module size, pinout, voltage and thermal requirements are defined, giving hardware designers a clear blueprint.
2. Building an open ecosystem and a secure supply chain
For data center buyers (hyperscalers) like Meta and Google, MSAs are a lifeline:
Avoiding vendor lock-in: If only one vendor can build a given spec, buyers are stuck the moment that vendor hits capacity problems or raises prices.
More choice: MSAs ensure multiple suppliers offer the same product, so buyers can choose freely based on price, lead time and quality.
3. Accelerating innovation and lowering cost
Division of labor: Chip vendors (e.g. Broadcom), module makers (e.g. Eoptolink) and connector makers (e.g. TE) can each develop against the same standard without wasting time defining the basics.
Economies of scale: When the whole industry adopts MSA specs like OSFP or QSFP-DD, volumes rise and unit prices naturally fall.
MSA vs. official standards (e.g. IEEE) | Attribute | MSA (Multi-Source Agreement) | IEEE (official standard) | Scope: physical form factor, mechanical structure, pinout vs. transmission protocol, encoding, physical layer (PHY) | Speed: fast (a few major players agreeing is usually enough) vs. slow (requires rigorous legal and organizational review) | Binding force: a commercial contract (ignore it and you have no market) vs. an internationally recognized standard
With AI compute exploding, technology moves too fast for IEEE's standardization timeline. That is why we have recently seen groups like LPO MSA and OCI MSA spring up one after another. They are the result of industry leaders racing to stake out territory early in hot areas such as 1.6T and silicon photonics integration.
2026 - 2020: The AI and High-Performance Computing Transition, Summarized
MSA | Founded | Core Technology & Purpose | Key Members (abridged) | Core Value |
XPO | 2026/03 | 12.8T ultra-high-density pluggable + integrated liquid cooling | Arista, Microsoft, Eoptolink | Pushes physical limits to solve extreme cooling in AI compute pools. |
OCI | 2026/03 | Chip-level optical interconnect (Optical Chiplets) | NVIDIA, AMD, OpenAI, Meta | Breaks copper's reach limit to enable GPU scale-up. |
Open CPX | 2026/03 | CPO (co-packaged optics) spec standardization | Marvell, Coherent, Samtec | Builds an interchangeable CPO ecosystem and lowers the barrier to entry. |
ACC | 2026/02 | Active copper cable, no DSP | NVIDIA, Broadcom, Amphenol | For short reach: cheaper than fiber, longer than passive copper. |
LPO | 2024/03 | Linear pluggable optics, no DSP | NVIDIA, Arista, Broadcom | Cuts power by 50%, solving thermals in the 800G era. |
ELSFP | 2021/12 | External laser source (ELS) packaging | Microsoft, Cisco, Intel | Keeps lasers away from hot ASICs and supports hot-swap servicing. |
OpenZR+ | 2020/09 | Coherent optics interoperability | Cisco, Arista, Lumentum | Lets routers connect directly to data centers across cities (DCI). |
CW-WDM | 2020/06 | Multi-wavelength continuous-wave laser specs | Intel, NVIDIA, Lumentum | Defines the "optical power" supply specs CPO needs. |
2017 - 2016: The Cloud Data Center Foundation Era, MSAs Summarized
MSA | Founded | Core Technology & Purpose | Key Members (abridged) | Core Value |
SFP-DD | 2017/05 | Dual-lane small form factor for servers | NVIDIA, Broadcom, Dell | High-density interface for AI server NICs. |
OSFP | 2016/11 | 8-lane package with built-in heat sink | Arista, Google, NVIDIA | The go-to choice for 1.6T, with the industry's best thermal performance. |
QSFP-DD | 2016/03 | Double-density package with backward compatibility | Broadcom, Cisco, Intel | Maximizes reuse of legacy investment; the dominant form factor of the 400G era. |
A Closer Look at Key MSAs
1. XPO MSA (eXtra-dense Pluggable Optics)
Founded: March 12, 2026
Purpose: Define next-generation 12.8 Tbps ultra-high-density pluggable modules, specifically targeting the bandwidth density and cooling needs of AI training clusters.
Full membership: Arista Networks, Microsoft, Ciena, Coherent, Marvell, Molex, Samtec, TeraHop, Lightmatter, Eoptolink, Genuine Optics, MultiLane.
Core value: Delivers 4x the rack density of today's OSFP and supports liquid cooling via an integrated cold plate, pushing pluggable packaging to its physical limits.
2. OCI MSA (Optical Compute Interconnect)
Founded: March 12, 2026
Purpose: Establish an open physical layer (PHY) specification for chip-level optical interconnect (optical chiplets), letting compute engines scale up directly over optics.
Full membership: AMD, Broadcom, Meta, Microsoft, NVIDIA, OpenAI.
Core value: Enables direct optical scale-up communication between processors and switches, or between processors, breaking copper's reach limit.
3. Open CPX MSA (Open Co-packaging)
Founded: March 12, 2026
Purpose: Develop standard specs for optical engines, covering connector mechanics, thermal management, electrical pinout and management interface, to build an interchangeable CPO ecosystem.
Full membership: Ciena, Coherent, Marvell, Molex, Samtec, TeraHop.
Core value: Brings the success of pluggable modules to CPO, ensuring end users have a stable multi-vendor supply.
4. ACC MSA (Active Copper Cable)
Founded: February 23, 2026
Purpose: Create a unified spec for active copper cables, ensuring interoperability across vendors and defining electrical, firmware and test specifications.
Full membership: AMD, Amphenol, Broadcom, Celestica, Ciena, Cisco, Dell Technologies, HPE, Keysight Technologies, Luxshare-ICT, MACOM, Molex, Multi-Lane, NVIDIA, Semtech, TE Connectivity.
Core value: Replaces the DSP with linear equalization, offering a short-reach interconnect that costs less than fiber and reaches farther than passive copper.
5. LPO MSA (Linear Pluggable Optics)
Founded: March 26, 2024
Purpose: Standardize linear pluggable optics, removing the DSP from the module to optimize data center connectivity.
Full membership: Accelink, Adtran, Altera, AMD, Amphenol, AOI, Arista, Broadcom, Bytedance, Cisco, Colorchip, Eoptolink, EXFO, Formerica, Genuine Optics, H3C, Hisense, Hyper-photonix, Infraeo, Inpho, Insiga, Intel, Jabil, Juniper, Keysight, KHtech, Link, Lumentum, LUXIC, Luxshare, MACOM, MaxLinear, Multi-lane, NewPhotonics, Nokia, Nubis, NVIDIA, O-Net, PioSeed, Ruijie Networks, Semtech, Source Photonics, TE Connectivity, TeraSignal, Texas Instruments, Wilder-tech, VIAVI, Zhaolong, 1-via.
Core value: Dramatically cuts optical module power, cost and latency; currently a key lever for solving the thermal bottleneck in AI compute clusters.
6. ELSFP MSA (External Laser Small Form-Factor Pluggable)
Founded: December 2021
Purpose: Define the external laser source package for CPO architectures, supporting blind-mate and hot-swap.
Full membership: Cisco, Microsoft, Broadcom, Intel, Juniper, Lumentum, Coherent, Samtec, OE Solutions, Xscape Photonics.
Core value: Separates the laser source from the hot ASIC, making remote laser servicing "as easy as swapping a pluggable module."
7. OpenZR+ MSA (Coherent Interoperability)
Founded: September 2020
Purpose: Combine 400ZR interoperability with OpenROADM performance to enable long-haul transmission with coherent optics in a pluggable form factor.
Full membership: Arista, Cisco, Fujitsu, Innolight, Juniper, Lumentum, NTT, Acacia, Coherent, Gigalight, Marvell, Molex, NEC, Retym, Windstream, EFFECT Photonics.
Core value: Drives IP-over-DWDM architectures for low-cost long-haul data center interconnect (DCI).
8. CW-WDM MSA (Continuous-Wave WDM)
Founded: June 2020
Purpose: Standardize O-band continuous-wave laser sources for silicon photonics and CPO.
Full membership: Arista, Ayar Labs, Coherent, imec, Intel, Lumentum, Luminous Computing, MACOM, Quintessent, Sivers Photonics, Sumitomo, AMF, Axalume, Broadcom, HPE, Keysight, NVIDIA, Samtec, GlobalFoundries, and others.
Core value: Ensures spectral and power compatibility between the external light source (ELS) and the optical engine.
9. SFP-DD / SFP112 MSA
Founded: May 2017
Purpose: Define a dual-lane small form factor interface for servers and edge devices.
Full membership: Alibaba, Broadcom, Cisco, Dell, HPE, Intel, Lumentum, NVIDIA, Molex, TE Connectivity.
Core value: Provides high-density connectivity on the server NIC side; the core interface of the AI server front-end network.
10. OSFP MSA (Octal Small Form-factor Pluggable)
Founded: November 2016
Purpose: Define 8-lane/16-lane pluggable modules with a high-efficiency thermal design.
Full membership: Arista, Google, NVIDIA, Broadcom, Cisco, Intel, Juniper, Coherent, Lumentum, Eoptolink, Source Photonics, Accelink, Amphenol, TE, Molex, Samtec, Keysight, VIAVI, Sumitomo.
Core value: A built-in heat sink supports high-power transmission; the standard package for 800G/1.6T AI networks.
11. QSFP-DD MSA (Double Density)
Founded: March 2016
Purpose: Extend QSFP by doubling the electrical lanes while maintaining backward compatibility.
Full membership: Broadcom, Cisco, Intel, Juniper, NVIDIA, Molex, TE, Lumentum, AOI, Amphenol, FIT, Keysight, Marvell, Sumitomo, and others.
Core value: Excellent backward compatibility lets data centers keep their existing equipment investment when upgrading.
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