Why White‑Box Switches Are Redefining Data Center Networks

White‑box switches decouple hardware and software by using standardized chip interfaces, allowing users to choose or customize the operating system and network functions independently of the underlying ASIC.

Hardware Components

Switching ASIC – core packet‑forwarding component with standardized interfaces.

CPU chip – controls overall system operation.

NIC – provides management connectivity for the CPU.

Storage – includes memory and disks.

Peripherals – fans, power supplies, and other components that must comply with OCP or similar standards.

Software Stack

The software layer consists of the network operating system (NOS) and its applications. The NOS abstracts hardware functions through the Switch Abstraction Interface (SAI), achieving true hardware‑software separation.

Market Landscape (2022)

According to Omdia, Ethernet switch port shipments grew 12% year‑over‑year. Vendor market shares were: Cisco 37%, Arista 18%, Huawei 8%, H3C 7%; white‑box vendors together held 14% of the market, a 4‑point YoY increase.

Advantages of White‑Box Switches

They offer higher flexibility, lower procurement and maintenance costs, and are widely adopted by cloud service providers and telecom operators for network transformation and reconstruction. Major hardware suppliers include Arista, Cisco, H3C, Dell, Quanta, etc.; NOS providers include Arrcus, Kaloom, Cumulus, Big Switch, FBOSS, and SONiC.

SONiC Open‑Source OS

Released by Microsoft in 2016, SONiC builds on SAI to separate the data plane from the control plane, enabling rapid software policy changes and topology adjustments. It is deployed by large cloud players such as Baidu, Microsoft, and Google.

Optical Circuit Switching (OCS)

OCS provides bandwidth‑agnostic, low‑power, low‑latency alternatives to electrical switches. Key benefits include:

Transparency to signal rates and protocols.

Power consumption < 1 W per 400 Gbps port (vs. >10 W for electrical switches).

Latency in the tens of nanoseconds.

Higher reliability due to fewer chips and components.

Challenges arise because OCS lacks packet‑processing capabilities; it requires accurate traffic prediction and dynamic optical matrix configuration. AI large‑model pre‑training can improve traffic forecasting, enabling broader OCS deployment.

Google OCS Deployment Example

Google replaces traditional spine switches with direct optical interconnects in its Jupiter and TPU data centers. By integrating WDM and circulators, Google increases the number of channels per fiber and achieves higher data‑rate transmission while reducing power consumption.

Commercial OCS Products

Companies such as Polatis, Coherent, and others have introduced commercial OCS solutions, indicating a growing market for optical switching in data centers.