Cumulus Networks and Broadcom Part Ways
– Now What?

The open networking market has certainly been an exciting place in 2020. Earlier in the year I wrote a blog titled “What Is the Impact of Arista Networks’ Acquisition of Big Switch Networks?” about Arista’s largest acquisition in February of 2020 and how that might play out in the market. Then a few months later I wrote in another blog titled “A Look at the Landscape after Nvidia Acquires Cumulus Networks” about the acquisition of Cumulus Networks by Nvidia, who had also acquired Mellanox just a few weeks earlier. In both of those blogs I made some observations and some predictions about the open networking market in general and Big Switch Networks and Cumulus Networks more specifically.

Arista and Big Switch Networks

As predicted Arista has focused their engineering and marketing investment on the packet broker side of the Big Switch business with a rebranding of Big Monitoring Fabric into DANZ Monitoring Fabric. Big Cloud Fabric, which was Big Switch’s OpenFlow-based SDN Data Center Fabric solution, seems have gotten the short end of the stick. According to customers Arista is out selling BCF customers on switching to Arista hardware and the EOS operating system. On the one hand that is probably a smart strategy for customers due to the many limitations associated with OpenFlow. On the other hand, customers who have invested in open networking infrastructure are being asked to swap out white box switches for proprietary Arista hardware. This is not only costly but these customers will also lose the ease of use of SDN – Arista has CloudVision but this only provides network management solution and not a highly automated SDN capability.

For customers looking to continue to leverage their white box switch investment Pluribus offers fully automated SDN solutions that can be loaded onto existing white box switches using an ONIE installer:

  1. Pluribus Adaptive Cloud Fabric for highly-automated, SDN-enabled single site and multi-site data center fabrics
  2. Pluribus Network Packet Broker, built on the Adaptive Cloud Fabric, for in-line and out-of-band network and security visibility

Nvidia/Mellanox and Cumulus – Broadcom Divorces Cumulus Networks

The real news here is something I did NOT predict – Broadcom cutting off all SDK access for Cumulus Networks. As first publicly reported by Greg Ferraro in a post on his @EtherealMind twitter channel,  Cumulus Linux 4.2 will be the last release to support Broadcom ASICs and SDK access is revoked.

Greg Ferraro Tweet

That means that after release 4.2 there will be no new features and no bug fixes. This is clearly a challenge for customers that have deployed Cumulus because their software is effectively end of life and they do not have an easy path forward.

Why did the Nvidia/Mellanox/Cumulus divorce with Broadcom happen?

Well as it turns out Mellanox aggressively competes with Broadcom directly at the chip level. There are many proof points such as this March 2020 sdxCentral article “Mellanox New Switch ASIC Targets Broadcom” or a head to head report commissioned by Mellanox “Tolly Report: Mellanox Spectrum Switch vs. Broadcom Tomahawk” and posted to the Mellanox website. As a key partner to Broadcom, Cumulus had comprehensive access to detailed roadmaps and technical specifications. Even if this flow of roadmap data was cut off, with SDK access Cumulus would still have access to documented APIs and could reverse-engineer key Broadcom innovations and architectural approaches.  So, as the new owner of Cumulus, this gave arch competitor Nvidia/Mellanox deep intelligence that Broadcom simply found unacceptable.

What is the implication for customers that have deployed Cumulus?

Customers that have deployed Cumulus Linux on Broadcom have a difficult path forward, but there are solutions to this challenge. Nvidia/Mellanox is, predictably, taking a similar path that Arista is taking with Big Cloud Fabric. As mentioned above, Arista appears to be suggesting to many customers to swap out their open white box hardware and replace it with Arista proprietary hardware and to also move to EoS and away from the Switch Light OS and the associated limitations of OpenFlow. However, in this case the urgency is not as great because Broadcom is still supporting the Switch Light OS. On the other hand, the Cumulus situation is more urgent as Cumulus Linux 4.2 is effectively at end-of-life on Broadcom-based white box switches. Therefore, Mellanox is aggressively suggesting a swap out from Broadcom-based white box switches to Mellanox-based switches and moving to a version of Cumulus OS running on the Mellanox chipset. With this approach customers are able to keep the same fundamental OS, but face an incredible challenge as they need to rip and replace every switch in the data center or campus which is extremely expensive and time consuming.

What about an alternative Open Networking OS?

A much lower cost option is to maintain existing Broadcom-based switches and leverage the power of open networking by loading an alternate Linux-based OS on to the bare metal switch. For data center and campus aggregation environments Pluribus Networks’ Linux-based Netvisor ONE is a great choice and can be easily loaded onto the existing switches using the Open Network Install Environment (ONIE). Another choice might be SONIC, but due to its current level of development and lack of enterprise features this is really more suited for large webscale enterprises that have significant software development and IT resources that can dig into the implementation. If you are looking for a Linux-based OS to deploy a data center network fabric that works out-of-the box with high performance and fully automated day 0, 1, and 2 operations, then Pluribus is a good choice. If you are interested in learning more about Pluribus Netvisor ONE as an alternative to Cumulus Linux then take a look at this page.

Additionally, in campus access environments where Cumulus Linux is deployed all the way down to the wiring closet the Pica8 OS can be a good choice. Pica8 has an nice blog on the Nvidia/Mellanox/Cumulus and Broadcom split here.

What is the implication for customers who are still considering Cumulus?

For those customers who are considering Cumulus on Broadcom-based switches but have not yet deployed, they have a few choices they can make. Obviously, they can go with a vertically integrated solution of Cumulus on Mellanox hardware. This of course looks no different than a Cisco approach and will result in vendor lock in as hardware and software are increasingly intertwined over time. Same story for Arista and EoS. This goes straight against the principles of disaggregation and the tremendous benefits the industry has seen in the compute and networking worlds to date. Alternately, they can stay the course of disaggregation and open networking and deploy a Linux-based open networking OS on bare metal switching hardware from vendors such as Dell, Edgecore, Celestica, Champion ONE and many more. Again, in the data center there are really two choices – SONIC for those who have large software development and IT teams and Pluribus Netvisor ONE for those looking for a fully SDN-automated out of the box data center fabric solution.

For more information on loading Pluribus Netvisor ONE on your bare metal data center switches you can visit https://www.pluribusnetworks.com/cumulus-networks-alternative-os/.

If you have any questions feel free to contact us here or send an email to sales@pluribusnetworks.com.

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About the Author

Mike Capuano

Mike Capuano

Mike is Chief Marketing Officer of Pluribus Networks. Mike has over 20 years of marketing, product management and business development experience in the networking industry. Prior to joining Pluribus, Mike was VP of Global Marketing at Infinera, where he built a world class marketing team and helped drive revenue from $400M to over $800M. Prior to Infinera, Mike led product marketing across Cisco’s $6B service provider routing, switching and optical portfolio and launched iconic products such as the CRS and ASR routers. He has also held senior positions at Juniper Networks, Pacific Broadband and Motorola.