The startup Arrcus has launched a new network operating system (NOS) to compete with integrated network devices from Cisco, Juniper, and Arista; as well as standalone commercial and open source NOSs.
Arrcus’s NOS, called ArcOS, is designed to run on whitebox switches and routers. It supports silicon from Broadcom, including the StrataDNX Jericho+ and StrataXGS Trident 3 chipsets, and well as Trident 2 and Tomahawk.
The company also says ArcOS runs on hardware from Barefoot, Mellanox, Cavium, Innovium, and switches from HPE, Accton, Celestica, and Dell.
In addition to announcing the general availability of ArcOS, Arrcus has announced a $15 million Series A investment from VCs General Catalyst and Clear Ventures.
Inside ArcOS
ArcOS combines open source and proprietary components. Its core is Debian Open Network Linux (ONL), with network applications and protocols running as microservices on top of ONL. These applications control the switching and routing functions.
Note that the company wrote its own applications and protocols, including BGP, OSPF, IS-IS, and MPLS. You won’t find open-source options such as Quagga or FRR in this OS.
The company notes that “ArcOS can be composably packaged with any Linux distribution tailored to individual environments.”
The company offers both perpetual and subscription licenses, but didn’t provide a price tag for the software.
Arrcus targets both switching and routing with its NOS. For instance, the company claims it can ingest and support a full Internet route table with Broadcom’s Jericho chipset and ArcOS. The company targets use cases including ISP peering, Internet edge services, CDN peering, multifunction PoPs, DCI, as well as leaf-spine designs in enterprise data centers.
Why Another NOS?
The rise of network disaggregation, in which the operating software is separate from the underlying hardware, has led to a flurry of development in ASIC options, hardware designs, and, of course, software.
Organizations interested in mixing and matching software and hardware to meet their unique network and business requirements have an embarrassment of riches. NOS options are available from commercial vendors and from open source communities such as the Linux Foundation.
Disaggregated network OS options include (but aren’t limited to):
- Cumulus Linux – Cumulus Networks
- DANOS – Linux Foundation
- IOS XR – Cisco Systems
- OcNOS – IP Infusion
- Open Network Linux – Open Compute Project
- OpenSwitch – Linux Foundation
- PicOS – Pica8
- Stratum Project – Linux Foundation
- Switch Light – Big Switch Networks
So what does Arrcus bring to the party?
Arrcus says it started from scratch by writing a hardware abstraction layer, which it calls the Dataplane Adaptation Layer. The company says this abstraction layer allows it to take advantage of new features and capabilities from ASIC vendors without disrupting its northbound software components, allowing customers to swap out hardware while preserving their investment in the software.
The OS supports OpenConfig and YANG and includes northbound APIs to support a variety of operations and management options. The NOS can integrate with tools such as Ansible, Chef, Puppet, and third-party orchestration systems such as OpenDaylight.
Those are good features, but programmatic access and the ability to integrate with automation and orchestration tools are table stakes at this point, not compelling differentiators.
As mentioned, Arrcus wrote its network applications and protocols from scratch. That’s a double-edged sword. A fresh approach can avoid the bloat and inefficiencies that creep into legacy code.
However, it also means new bugs have yet to be discovered, and unintended interactions are waiting to emerge. That’s just how it is with software, whether from a startup or an incumbent.
Fresh code that hasn’t been run through the mill of large-scale production deployments isn’t necessarily a deal-breaker, but customers need to be aware of potential risks.
Advantages For Arrcus
Aside from the technical merits of the software, which customers need to evaluate for themselves, I do think Arrcus has a couple of things going for it.
First, much of the early evangelization around disaggregation and whitebox has already been done, both by commercial vendors and by industry and open source bodies such as the Open Compute Project and the Linux Foundation.
That saves Arrcus a lot of tedious legwork having to educate potential customers. The organizations coming to Arrcus are likely to already understand the benefits of disaggregation, which allows Arrcus to focus on product value and competitive differentiation, and perhaps shorten the sales cycle.
Second, coming to market with a licensed product that Arrcus supports gives it an edge over open-source options that are strictly DIY. Customers can hedge some of the risk of disaggregation by choosing a product and company that will be on call when something goes wrong.
Arrcus says that in addition to providing software support, it will pull in the ODM if the issue is related to hardware.
If you’d like a separate take on Arrcus, Ethan Banks recorded a Brief Briefing about the new network OS.

