Next-gen Network OS (NOS) Architecture based on Open Network Linux (ONL)

The rapid adoption of open networking and software/hardware disaggregation is causing a renaissance in the networking industry!  The networking industry has largely been devoid of innovation in the past two decades. The adoption of Ethernet & IP networking in the 90’s helped standardize the protocol stack, making networking devices easy to interoperate, improve agility and reduce cost. However, for the last two decades, the networking software and hardware have architecturally remained about the same, and proprietary systems have led to vendor lock-in, lack of innovation & operational agility and prohibitive economics. The computing world, on the other hand, adopted open source software and industry-standard hardware which helped drive tremendous innovations we are witnessing today. 
Mainly driven by industry-standard x86 hardware, open source Linux OS and virtualization/containerization, compute has transformed from proprietary, hunky mainframe systems to scale-out distributed systems. Pace of innovation accelerated as each component innovated independent of the other vs monolithic vendor-controlled HW/SW compute stack. This rapid innovation has led to new business models like cloud and SaaS. Similarly the networking transformation must also be driven by disaggregation of the “NETFRAME” into modular HW/SW components and provide end users the freedom to innovate, to be in control, to have choice and to deliver agility. This transformation in networking has been taking place over the past few years, and is now reaching escape velocity!

Networking Innovations -- From Hyperscalers to Enterprises

Driven by the need for speed, economics, and vendor freedom, hyperscale organizations have been at the forefront of both networking software and hardware innovation. While these innovations are typically customized for the respective hyperscale environments, many parts of the software stack are being disaggregated and integrated by early adopters to adopt to their environments. Once proven by the early adopters, vendors engineer the innovation for enterprises deployments. This innovation cycle has now become the new norm for the networking industry, with adoption of CLOS fabrics, SDN and open networking hardware.

Next-gen Network OS: Open, Modular Architecture

The disaggregation of hardware and software layers of the switching stack is happening in multiple phases. This is creating an opportunity for unprecedented innovation in networking.

Phase 1: Disaggregation of Hardware from Software

Early designs from Google Pluto and Facebook’s contributions of open source switching hardware designs to Open Compute Project (OCP) are driving a burgeoning open networking hardware ecosystem. Today open networking switch hardware is available from more than a dozen white-box or branded white-box switch vendors. 

Phase 2: Open Networking Platform Software (Open Network Linux)

As a next phase of innovation, Open Compute Project (OCP) has been spearheading efforts to standardize open networking software and hardware. OCP’s Open Network Linux (ONL), is an open-source platform software layer that can be leveraged as a foundational component for end-users who want to build their own Network Operating System (NOS) on top of open networking switches. It has been validated on 68 open networking platforms across 11 whitebox/britebox suppliers.

Phase 3: Modular NOS Architecture

ONL has been built for open networking hardware platforms with a unique architecture for pluggable 'forwarding stack’ and ‘device management & programming’ software.

The availability of open source protocol stacks such as FRrouting (FRR) has enabled organizations to rapidly innovate and build modern, modular, next-generation NOS stacks on open networking switches. 

OCP Summit 2018 Demonstration of the Modular NG-NOS architecture

The evolution of modular, NOS architecture has created unprecedented level of collaboration in the networking industry. Teams from Google, Facebook and Big Switch are demonstrating at the OCP Summit 2018 NG-NOS innovations leveraging open-source and modular architecture.  
All three NG-NOS demonstrations perform Layer-3 networking (routing): 
  • The Google demo shows this with SDN controller, Google NOS and P4 programming
  • The Facebook demo shows this with FBOSS and the Thrift protocol 
  • The Big Switch demo shows this with an open-source BGP protocol (FRrouting) and networking CLI. 
Using modular, interchangeable software and hardware components, this demonstration points to multiple open source networking innovations, including: 
  • Open source programming model on ONL-based OCP switches.
  • Multiple open source forwarding agents on Open Network Linux.
  • Multiple open source NOSs on ONL-based OCP switches.

Benefits of Modular, Open-Source Networking Stack

Data center organizations who are looking to innovate with open-source software can leverage an ONL-based modular, open-source NOS stack and gain complete freedom. For example:
  • SaaS, Telecom and cloud providers can easily customize an ONL-based NG-NOS stack for their deployments and experience order of magnitude improvements in choice, agility, flexibility, cost reduction and control compared to legacy close-NOS approach. 
  • Innovation-driven enterprises can leverage ONL-based NG-NOS for their digital transformation initiatives to demonstrate unprecedented agility, dramatic cost reduction and complete control through vendor-agnostic architecture.
Gartner Research (Jan 2017) has also predicted the continued evolution of this  trend with open-source networking software -- “By end of 2020, open-source, self-build and cloud alternatives will replace at least 20% of enterprise data center network total addressable market by shipment, up from less than 2% currently”
Networking software and hardware suppliers also benefit with these advances in open source networking:
  • Networking Software/NOS suppliers leveraging ONL and OCP switches can focus on software innovations at higher layers of the networking stack, instead of platform software to support multi-vendor open networking switch hardware
  • Switch hardware suppliers with OCP and ONL certified platforms can rapidly expand footprint with a rich set of multi-vendor NOS support, thus competing on better hardware designs and breadth of platform offerings.

ONL Adoption

Today ONL is gaining rapid adoption across multiple domains. 
  • Hyperscaler-NOS stacks are using ONL as their foundational platform to rapidly leverage open hardware ecosystem with modular NOS approach. 
  • Big Switch’s Commercial SDN fabric solutions use an SDN NOS Switch Light OS that is built on ONL. It is deployed in hundreds of large telecom, enterprise and SaaS data centers, which has hardened ONL for production deployments. 
  • ONF Cord Stack leverages the ONL platform software for open leaf-spine fabric for central offices.
  • Project Stratum led by Google and ONF is leveraging ONL as as part of open reference platform for “software-defined” data plane
  • NTT BGP Go Project is using ONL as a platform layer to demonstrate their EVPN Go BGO Project
  • Cisco IOS-XR is leveraging ONL/ONLP to demonstrate disaggregation of its carrier NOS on whitebox switch hardware

ONL Ecosystem and Certification Program

The ONL ecosystem is fast expanding with validation on 68 open networking platforms across 11 whitebox/britebox suppliers. With this broad industry adoption, ONL requires a structured approach for validation against the supported hardware platforms. The ONL Certified Gold program announced by Big Switch provides continuous testing of ONL versions on designated britebox and whitebox platforms, providing assurance to organizations adopting ONL of complete code validation. At the time of program launch, HPE, Edgecore, Quanta Cloud Technologies (QCT), and Delta Networking Inc (DNI) have gone through the validation for multiple platforms to achieve the ONL CertifiedTM Gold status.  ONL hardware compatibility list (HCL) provides a comprehensive list of supported platforms with ONL certification status. 
These are exciting times in the networking industry! With open networking hardware and software we finally have the freedom to run fast (agility), freedom to innovate (control), freedom to choose vendors (choice), and freedom to reduce cost (economics)!!

Prashant Gandhi, Chief Product Officer


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