ONF targets Stratum open source reference platform at white box switch support

The Open Networking Foundation (ONF) has unveiled Stratum, an open source project that aims to promote the development of white box switches through the implement a software platform that leverages the ONF's newly announced next-generation software-defined networking (SDN) interfaces. The initiative has attracted the participation of companies from across the data center networking community, including both telecom services and cloud providers. The latter demographic includes Google, which will help get the project rolling by providing what will amount to the first revision of source code for Stratum.

Despite the efforts of previous initiatives, current open system white box switches haven't fully achieved plug-and-play status, according to Timon Sloane, vice president of marketing and ecosystem at the ONF. The Stratum project will seek to address this shortfall by leveraging the newly released SDN interfaces, which improve lifecycle management and control. Sloane described these interfaces as successors to OpenFlow that enable improved negotiation between the network operating system (NOS) and the data plane. They more fully enable a pipeline "contract" as well as pipeline control, configuration, and operations. The result is more deterministic performance, he said.

Stratum will use these advances to focus on the enablement of comprehensive design and runtime instrumentation. The effort seeks to enable interchangeability of forwarding devices and programmability of forwarding behaviors. The result should be the creation of a broader white box switch ecosystem that includes a wider variety of switching silicon, Sloane said. The software also will enable traditional switches to support programmable pipelines, the ONF expects.

The project has attracted representatives from across the switching ecosystem. Founding members include:

• Cloud providersGoogle and Tencent
• Telecom operators China Unicom, NTT, and Turk Telekom/Netsia
• Networking vendors Big Switch Networks, Ruijie Networks, and VMware
• White box ODM vendorsDelta, Edgecore Networks, and QCT
• Silicon vendors Barefoot Networks, Broadcom, Cavium, Mellanox, and Xilinx
• Open source projects such as CORD, ONL, ONOS, OpenSwitch, OVS, P4.org, and SDKLT.

To get the ball rolling, Google will provide source code that it has already implemented that will become open source. In fact, Google expects to implement Stratum software by the end of this year. The Stratum software will be in an incubation period for the rest of this year, during which all members will have access to the software under development. The project will shift into open source mode early in 2019, with release under the Apache 2.0 open source license.

The ONF currently envisions four use cases for Stratum software:

1. Cloud SDN Data Plane: This is the use case in which Google has the most immediate interest. As noted, Google has donated an initial code base for Stratum from its production codebase in the expectation that it will be able to use Stratum in its production networks quickly. Google will pair Stratum with the company's internal SDN controller to manage and control Stratum-based white box switches. Other network operators with proprietary controllers could follow Google's lead.
2. Cloud SDN Fabric Platform: Those who use the ONF's ONOS plus Trellis software can run it natively over Stratum as a P4 data plane switching layer.The result is an open source approach to programmable SDN data center spine-leaf fabrics, the ONF says.
3. Central Office Re-architected as a Datacenter (CORD): CORD also runs over Trellis and ONOS, which means Stratum can play a role in CORD environments as well.
4. Thick Switches with Embedded Control: While Stratum will be optimized to support "thin switch" implementations, developers also can use it with an embedded NOS running within the same switch. This "thick switch" configuration enables the replication of the traditional model of embedded management and control (e.g., Netconf, SNMP, BGP) within a single system. As a result, more conventional, tightly integrated systems can leverage Stratum to benefit from the latest SDN interfaces.

The Stratum project welcomes new members who wish to participate in the program. Additional information can be found on the ONF website.

For related articles, visit the SDN/NFV Topic Center.

For more information on high-speed transmission systems and suppliers, visit the Lightwave Buyer's Guide.