I’ve been writing about Cumulus Networks since it launched a handful of years ago. The networking vendor was, at its inception, focused on offering an open source operating system that organizations could run on a range of different networking switches. Since that time there have been changes (the hiring of a new CEO, for a start and, more jarringly, the move to offering a converged software plus hardware offering), but the original mission – that of disrupting the hegemony that the traditional networking vendors have in the marketplace, hasn’t changed.

Essentially Cumulus’ aim is to allow every-day organizations to adopt networking approaches that the large webscale vendors utilize. By allowing organizations to use standard hardware components, and an open software layer, Cumulus aims to help those organizations to increase their speed and agility, all the while reducing the horrendous costs structures of those legacy players.

Anyway – Cumulus seems to have gone from strength to strength and, off the back of an impressive year of growth, is announcing a Series D investment round that, interestingly (at least from my perspective in the Southern Hemisphere) is being led by Australian telco Telstra and its venture arm. The funding is, at least in part, designed to help Cumulus push further into the APAC and EMEA regions.

The round takes Cumulus’ total funding to $129 million and also included existing investors including Andreessen Horowitz, Battery Ventures and Sequoia Capital (or, in other words, pretty much the cream of the high-profile venture capital crop).

Growth to date

Alongside the raise, Cumulus’ CEO, Josh Leslie, opened up with some details of the sort of growth his company has been seeing. Some data points:

  • During 2017, the company signed over 350 new customers and now serves more than 800 customers, including over a third of the Fortune 50
  • Growth outside the U.S. was particularly strong. Cumulus tripled its business in the Asia Pacific region and more than doubled its business in EMEA during 2017
  • Cumulus Networks debuted in the Visionaries quadrant of the 2017 Gartner Magic Quadrant for Data Center Networking
  • In October 2017, Cumulus was inducted into the Innovation Hall of Fame by JP Morgan Chase


2017 also saw the appointment of one of the more successful networking entrepreneurs of late, Martin Casado, to the Cumulus board. Casado was the co-founder of software-defined networking vendor Nicira, which was acquired by VMware for $1.26 billion. Since then Casado has become a venture capitalist (yes, the career path of many successful entrepreneurs) and is now a general partner at Andreessen Horowitz. Casado’s knowledge will be hugely valuable to the Cumulus board.

2017 also saw an expansion of the Cumulus product portfolio as the company released NetQ, a telemetry-based fabric validation system; Host Pack, software essentials for the host enabling web-scale networking for containers, microservices and more; and Cumulus in the Cloud, a personal virtual data center to build and test network designs and operations.

The Aussie angle

I’m interested in the Telstra angle since, in my experience, telcos, and telcos in smaller markets in particular, have been slow to understand the value of these sort of investments. Discussing the investment, Mark Sherman, Managing Director, Telstra Ventures talks about the history his company has had with Cumulus:

Telstra Ventures is focused on investing in strategic, value-added businesses that show strong market fit and growth potential. In this case we had the advantage of being a Cumulus Networks customer first, which gave us several months of first-hand experience working with their products, services and team. After that experience, we were eager to expand our partnership and invest in the company. Open networking is key to growing service provider capabilities and we are thrilled to have Cumulus join our portfolio of strategic, innovative companies.


Interesting timing, especially given some upcoming news related to open source networking. The investment quantum is an indication of both the opportunity and, more importantly, the success Cumulus has had executing upon that opportunity. My only question is how long it will be before VMware, Cisco or Juniper acquire this fast-moving company.

Ben Kepes

Ben Kepes is a technology evangelist, an investor, a commentator and a business adviser. Ben covers the convergence of technology, mobile, ubiquity and agility, all enabled by the Cloud. His areas of interest extend to enterprise software, software integration, financial/accounting software, platforms and infrastructure as well as articulating technology simply for everyday users.

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