This project resulted in an implementation agreement for a 400ZR coherent optical interface. It is relevant for router-to-router interconnect use cases and is targeted at (passive) single channel and amplified DWDM applications with distances up to 120 km. This IA ensures a cost-effective and long-term relevant implementation using single-carrier 400G, coherent detection and advanced DSP/FEC algorithms. Release of an update supporting 75 GHz channel spacing is imminent!

Press Releases



  • NGON and DCI World  – OIF Pre-Conference Workshop – OIF Project Updates
    Presenters: Dave Brown, OIF Dir of Communications, Nokia; Karl Gass, OIF Physical & Link Layer Working Group – Optical Vice Chair – June 21-23, 2022 June 21, 2022 – 2:30pm-3:15pm CEST
  • OFC 2022 – OIF Panel: “Deployment of 400ZR and the ongoing OIF work to define 800ZR/LR”
    Moderator: Richard Ward, OIF MA&E Committee Co-Chair – PLL, Intel Panelists: Josef Berger, Marvell; Ian Betty, Ciena; Mark Filer, OIF VP, Google; Tom Williams, Cisco
  • OFC 2021 – OIF Panel: “400ZR Deployment and What’s Next: An OIF Update
    Moderator: Richard Ward, OIF MA&E Committee Co-Chair – PLL, Intel
    Panelists: Ian Betty, OIF President, Ciena; Josef Berger, Marvell; Tom Williams, Cisco;  Paul Brooks, Viavi Solutions
  • NGON & DCI World 2019 – The Optical Masterclass Series – Optical Internetworking Forum (OIF) Panelists: Dave Brown, Nokia and OIF Director of Communications and Karl Gass, OIF Physical & Link Layer Working Group Vice Chair, Optical
  • OFC 2019 – OIF Panel on Showfloor: “400ZR Specification Update
    Moderator: Karl Gass, OIF PLL WG Vice Chair, Optical
    Panelists: Josef Berger, Inphi; Mark Filer, Microsoft; Mark Stiller, NeoPhotonics; Marcus Weber, Acacia Communications
  • OFC 2018

For more information, contact Karl Gass, Physical and Link Layer Working Group, Optical Vice Chair at

For information on other OIF current projects, please see OIF Current Work

For public OIF Implementation Agreements, please see Implementation Agreements (IAs)