Release of the First Open Control Module (OCM) Hardware Specification for White‑Box Switches

After more than half a year of research, drafting, discussion, and feedback collection, the first control module standard for white‑box switches—Open Control Module (OCM)—has been officially released.

The OCM specification aims to standardize white‑box switch control modules, which are critical for system stability, integration efficiency, and field operation. Existing problems include mismatched vendor modules, resource‑wasting duplicate matching, and inadequate stability, as well as CPU card standards that are too complex and unsuitable for white‑box switches, and high‑speed interfaces that cannot meet new switch chip requirements.

The new OCM standard, designed from user system requirements, provides a concise, practical hardware standard for next‑generation white‑box switch control modules. It solves the current issues by supporting higher data rates and bandwidth of new switch chips, allowing CPU iteration and diversification, and accommodating domestic CPU chips. The specification covers structural design, signal definitions, system design requirements, high‑speed signal constraints, thermal and environmental considerations.

The S³IP “standardized white‑box ecosystem” project, launched in November 2020 by Alibaba, Tencent, Baidu, Meituan, JD, Kuaishou, and China Academy of Information and Communications Technology, has driven the development and adoption of the OCM standard. The project’s launch event in July 2021 attracted over 200,000 online viewers and 500 on‑site participants. Since then, the ecosystem has grown to 12 member companies, with more expected to join.

In July 2021, the S³IP consortium released three white‑box hardware white papers—S³IP hardware base function specification, sysfs specification, and PIT specification—providing unified hardware foundations and standard sysfs information, reducing adaptation difficulty for Sonic OS. By February 2022, the sysfs and PIT open‑source code were completed, and all participating vendors had adapted their products to the S³IP standards, delivering both reference documentation and usable open‑source code to the industry.