OIF advances optical interoperability
OIF has approved new agreements for link training and coherent optical module management, supporting interoperable high-speed connectivity for AI and data-intensive networks.
The Optical Internetworking Forum (OIF) has approved two new Implementation Agreements (IAs) aimed at improving interoperability across high-speed optical networks as AI and data-intensive applications drive demand for faster and more efficient connectivity.
The agreements were approved during OIF’s Q3 2026 Technical and Market Awareness & Education Committees Meeting, held in Montréal, Canada, which brought together more than 200 representatives from member companies.
The new CMIS Out-of-Band Link Training (CMIS-LT) IA supplements the Common Management Interface Specification (CMIS) by defining standardised mechanisms for per-lane and per-direction link training across a module’s host interface.
As host interface speeds increase and signal margins become tighter, link training is becoming increasingly important for maintaining signal performance.
The new agreement provides a common method for transmitters and receivers to exchange the information required to optimise signal-shaping parameters through the CMIS management interface.
OIF has also approved an updated Coherent CMIS (C-CMIS) 1.5 IA, extending CMIS to support the management of digital coherent optics (DCO) modules.
The specification defines additional management registers, Command Data Block messages, diagnostic monitoring and coherent-specific functionality.
Version 1.5 focuses on 400ZR modules supporting a single 400G Ethernet data path, an eight-lane host interface and a single-lane 400ZR coherent media interface.
The standard is intended to simplify the integration of coherent pluggables into routers and switches while supporting predictable, multi-vendor operation.
Alongside the two agreements, OIF members continued work on coherent interfaces, CMIS and Near-Package Optics (NPO). These initiatives are targeting the increasing bandwidth and optical connectivity requirements of next-generation switches and xPUs.
OIF said its members will continue demonstrating interoperability work at industry events through the remainder of 2026, including ECOC 2026 in Málaga, where 39 member companies will participate in a multi-vendor interoperability demonstration covering initiatives including CEI-448G, CEI-224G, CMIS, co-packaging and energy-efficient interfaces.
The developments highlight the growing importance of common optical and electrical interface standards as AI infrastructure pushes network bandwidth higher and increases the need for interoperable optical connectivity.
