ADVA are calling Ensemble Activator the first true carrier-grade network operating system for bare metal switches. They have aligned themselves strongly with the Telecom Infra Project and in particular the Open Optical and Packet Transport (OOPT) project. At present ADVA sits on the disaggregated cell site routers from Edgecore Networks and Delta and some aggregation routers from Edgecore.
https://www.adva.com/en/products/disaggregated-networking/ensemble-activator

Altran are the 2nd of the new players into the world of open networking in the last year, with the launch of the SDN-enabled virtualized access solution or SDvAS for short. This open networking framework brings together work from the ONF with their SEBA and vOLTHA projects, the Broadband Forums OB-BAA, and Altran’s own Intelligent Switch Solution (ISS). Altran also announced an NOS based on ISS for the disaggregated cell site routers previously mentioned and will soon have an extensive portfolio of bare metal switches to add to its arsenal. Watch this space!
https://northamerica.altran.com/software/intelligent-switching-solutions

ArcOS is the main offering from Arrcus. They also offer a route reflector with ArcRR, monitoring with ArcIQ, and finally, Arrcus VDR, which is their distributed routing platform for bare metal. They have also partnered with all the major players on the hardware side in Edgecore, Celestica, Quanta and Delta. They offer 2 solutions at present, the first being a BGP-EVPN multi-tenancy fabric for spine and leaf data centers and the 2nd being their multi-cloud networking platform.
https://www.epsglobal.com/products/open-networking/network-operating-systems/arrcus

BeyondEdge™ solves the ever-growing challenges that come with complex networks and proprietary hardware by providing the only 100% software-defined, unified network platform that is both vendor and technology agnostic. This solution simplifies network architecture and management and enables businesses to succeed faster, while delivering marked value and enabling the simple addition of emerging technologies, such as 5G and IoT.
https://www.epsglobal.com/products/open-networking/network-operating-systems/beyondedge

Probably the most well-known of the NOS vendors, Cumulus are a well-respected and a very well-run software company. Based on Debian, Cumulus Linux (link to our site) is primarily a Data Centre NOS which allows you to automate, customize and scale the network with ease. Cumulus also offer a network operations tool called NetQ which gives you operational intelligence about the health of your data centre in real time. They were recently bought by Nvidia to marry in with their Mellanox acquisition which should see them capable of competing with Cisco and Juniper at every level.
https://www.epsglobal.com/products/open-networking/network-operating-systems/cumulus-networks

DriveNets Network Operating System or DNOS for short is a distributed OS that runs over Docker containers with the data plane running on a cluster of bare metal switches and the control plane on a bare metal server, or indeed any environment that supports containers. DriveNets also has a networks orchestrator or DNOR that simplifies deployment, integration, and the management of the disaggregated network for service providers.
https://drivenets.com/products/dnos/

ExaNOS from Exaware provides a feature-rich, carrier-grade, high-scale routing NOS for multiple use cases such as, mobile backhaul, disaggregated cell site router, peering, edge and core applications. Their solution can enable fixed and mobile service providers to transform their networks and build massively scalable infrastructures to support the growing traffic demand, while keeping your costs predictable, under control by using bare metal from the likes of Edgecore Networks and Delta. Although they are a new company, they have a lot of experience in the routing business previously as Compass Networks. One to watch out for.
https://www.epsglobal.com/products/open-networking/network-operating-systems/exaware

IPI as they are generally known have an interesting story in this domain. The company is around since 1999 and they originally created ZebOS from open source routing software called Zebra. IPI went on to sell ZebOS as an OEM product up until creating their own version of NOS called OcNOS. IPI have been very successful in recent years in their endeavours, partially down to their ability to leave the data centre behind and tackle other markets. OcNOS’s ability to provide extensive protocol support for MPLS is proving invaluable. They have recently made great strides in the telco sector providing the NOS for the Cassini Transponder, cell site routers, aggregation routers and SD-Edge solutions on bare metal.
https://www.epsglobal.com/products/open-networking/network-operating-systems/ip-infusion

Kaloom is another new addition to the ever-growing list of NOS vendors and their Software Defined Fabric is a play for the hyperscale and distributed datacenter market. They have partnered with Edgecore and Delta on the hardware side to produce a fully containerised DC and edge solution. They also have an edge solution for 4 and 5G applications called Cloud Edge fabric which is suited to the telco central office or the CORD platform from the ONF.
https://www.epsglobal.com/products/open-networking/network-operating-systems/kaloom

NoviWare Network Operating System is for use in high performance, fully programmable forwarding planes and uses the Barefoot Tofino chipset. They have their own hardware in the form of NoviSwitch but also work on Mellanox, UfiSpace, and Edgecore’s Wedge series that Facebook use. It is a reliable platform for OpenFlow, gRPC, and P4-Runtime SDN applications.
https://noviflow.com/noviware/

Open Networking Operating System (ONOS) is an open source NOS designed to help service providers build carrier grade software defined networks that are both highly scalable and high performance. It is run by the Linux Foundation but has found a permanent home in a lot of the projects run by the ONF and their CORD platform. ONOS can also act as a controller for enterprise and campus networks.
https://www.epsglobal.com/products/open-networking/network-operating-systems/onos

Open Network Linux (ONL) is a completely free, open source NOS for bare metal switches from the Open Compute Project (OCP). The OCP mainly deal with hardware in the open networking world but ONL acts as a foundational layer on top of the hardware which in turn allows end users to build their own NOS on top of whitebox switches. Big Switches Switch light OS is based on ONL.
https://opennetlinux.org/

Another open source Linux-based NOS with this one coming from the Linux Foundation. As always with the Linux foundation the goal is to create a community based on collaboration and innovation that benefits everyone. Unfortunately for OpenSwitch SONiC’s progression has been to its detriment.
https://www.openswitch.net/

One of the founding fathers in this area of networking, Pica8 have 2 different flavors of NOS. Both are called PICOS (link to our website) with an enterprise edition and an SDN edition. Again, this is a Debian Linux based NOS. Pica also offer an Ansible based automation framework that couples Zero-Touch Provisioning (ZTP) with ONIE to simplify installation and operation of the switches across the entire enterprise.
https://www.epsglobal.com/products/open-networking/network-operating-systems/pica8

One of the elder statemen now, we have Pluribus Networks (link to our site) and their Netvisor One open source operating system. It is a L2/L3 NOS with automated provisioning and management, along with embedded telemetry and advanced analytics. This NOS works for brownfield sites which means it does not have to be a rip and replace of the existing network. Pluribus also have a few other strings to their bow and their Adaptive Cloud Fabric is proving hugely popular in being able to create a controllerless fabric over multiple locations and also their recently released Network Packet Broker, which is also proving popular.
https://www.epsglobal.com/products/open-networking/network-operating-systems/pluribus

Another new entry on the 2020 NOS vendor list but they have been around a while and have been deep in PoC mode with some large European telcos. Their NOS is called FullStack and has an array of uses cases such as vBNG, PE router, backhaul and mobile aggregation, and DC routing. 3 of the fundamental differences to previous OS’s are, state databases in each network device, created using composable code, and finally being built using a cloud native approach with independent microservices running in Linux containers. The 2nd half of 2020 could be very interesting if and when RtBrick finally emerge from the shadows.
https://www.rtbrick.com/

Software for Open Networking in the Cloud (SONiC) is the software used by Microsoft to power Azure. This means that it is coming from a hyperscaler who has already put it into large scale production, so it is battle tested and hardened. It has now been implemented by other hyperscalers and large enterprises. SONiC is built on the Switch Abstraction Interface (SAI which Microsoft also created) which defines a standardized API. Microsoft have open sourced SONiC and gifted it to the OCP and it is available to download free on GitHub. There are multiple versions about to come out with Broadcom’s edition getting plenty of traction.
https://www.epsglobal.com/lp/open-networking-solutions/microsoft-sonic?viewmode=0

Stratum is an open source silicon-independent switch operating system for software defined networks. It is building an open, minimal production-ready distribution for white box switches. Stratum exposes a set of next-generation SDN interfaces including P4Runtime and OpenConfig, enabling interchangeability of forwarding devices and programmability of forwarding behaviours. Stratum goes hand in hand with ONOS, which we previously mentioned, in projects run by the ONF for the central office like CORD.
https://www.epsglobal.com/products/open-networking/network-operating-systems/stratum

Last but not least we have Volta Elastic Virtual Routing Engine or VERVE as they call it, is a cloud-based network platform. They call it a platform and not a NOS, but I am sticking them in any way! Like some of the other new vendors this year it is very much in the service provider realm and has a multitude of use cases. It sits on the cell site routers I have previously mentioned and has some great use cases there in multitenancy arrangements due to supporting 255 virtual routers per device. It can also be used as a PE router, peering router, and multiple edge and backhaul scenarios.
https://www.epsglobal.com/products/open-networking/network-operating-systems/volta