Introduction:
SDN proponents cite the proprietary, closed and tightly integrated hardware/software architectures of switch/routers being an impediment towards achieving network agility, more efficient bandwidth utilization, and lower costs. That’s because those boxes are complex, aren’t generally inter-operable with other vendor gear, and are almost impossible to control using external software.
With more intelligence built into silicon from companies like Broadcom, Intel, Marvell, and others, there are fewer advantages of the proprietary, vertically integrated switch/ routers, which enjoy very high profit margins (for vendors like Cisco, Juniper, Brocade and even Arista Networks). And those L2/L3 network fabrics can’t be easily controlled by external software to meet the needs of the applications that use them for connectivity.
James Hamilton, Distinguished Engineer at Amazon Web Services wrote in a blog post last week:
“Because networking gear is complex and, despite them all implementing the same RFCs, equipment from different vendors (and sometimes the same vendor) still interoperates poorly. It’s very hard to deliver reliable networks at controllable administration costs from multiple vendors freely mixing and matching. The customer is locked in, the vendors know it, and the network equipment prices reflect that realization.
Not only is networking gear expensive absolutely but the relative expensive of networking is actually increasing over time. Tracking the cost of networking gear as a ratio of all the IT equipment (servers, storage, and networking) in a data center, a terrible reality emerges. For a given spend on servers and storage, the required network cost has been going up each year I have been tracking it. Without a fundamental change in the existing networking equipment business model, there is no reason to expect this trend will change.
What is missing is high quality control software, management systems, and networking protocol stacks that can run across a broad range of competing, commodity networking hardware. It’s still very hard to take merchant silicon ASICs packaged in ODM produced routers and deploy production networks. Very big datacenter operators actually do it, but it’s sufficiently hard that this gear is largely unavailable to the vast majority of networking customers.”
Enter Cumulus Networks:
A completely different approach was announced last week by Cumulus Networks- a stealth mode start-up that announced it has built a Linux-based operating system for “bare metal” or commodity switches.
Cumulus Networks, founded by x-Cisco engineers JR Rivers and Nolan Leake, announced a Linux-based real time operating system to control the commodity switches (that use merchant silicon) being built by Quanta, Accton, Foxconn and other ODMs. The company has raised money from investors that include Andreessen Horowitz, Battery Ventures and VMware founders Diane Greene and Mendel Rosenblum.
Cumulus will provide a simple, open, and stable Linux-based Network OS that enables ODMs and merchant silicon manufacturers to provide multiple, common commodity hardware platforms for switching and routing. The company calls that “Disaggregating the Network” as shown in the before and after illustrations below.
The rise of merchant switch silicon and “bare metal” switches enables a paradigm shift to an open network ecosystem.

locked onto one vendor. Image courtesy of Cumulus Networks.
After

The company claims that:
“Cumulus Linux is the first true Linux OS. It enables users to take full advantage of the latest industry standard networking hardware while enabling the latest Linux applications and automation tools, delivering new levels of agility, scalability and flexibility to the enterprise data center. Now you can choose from a number of native Linux applications, and third party applications can be integrated as add-on Linux packages to optimize your business. Cumulus Linux enables a consistent experience between the network and the compute, and it brings about the missing piece to fuel the next wave of scale, collaboration and innovation in networking, realizing the full extent of a Software Defined Data Center.”
The advantages of this new approach to data center networking are claimed to be:
- Delivers unprecedented price-performance
- Enables the next wave of scale, collaboration and innovation
- Simplifies orchestration, automation and monitoring of networks
- Consistent Linux-based toolsets for network and compute
- Lower OPEX/CAPEX
- Break free from vendor lock-in
- Enables large ecosystem of native Linux apps
Cumulus plans to generate revenue through the licensing of th Linux OS, maintenance, support, and yet-to-be announced feature sets layered on top of the OS. That is the same business model that Red Hat has around Linux for compute servers.
“Linux revolutionized the compute-side of the datacenter over the past 15 years. Having a common OS broke vendor lock-in, drove down server hardware cost, allowed scale-out architectures, and provided a common platform for innovations like virtualization. Meanwhile networking remained stagnant,” said JR Rivers, co-founder and CEO of Cumulus Networks. “Innovation is finally coming to the network, and we are bringing that same transformational impact that Linux has had on datacenter economics and innovation to the networking side of the house.”
Piston Cloud Computing, Inc., focused on enterprise OpenStack, announced a technology partnership with Cumulus Networks last Wednesday, June 19th.
Whither SDN?
SDN is another way to open up the data center network and create a more open ecosystem. However, Gigaom reported that SDN was not a hot topic at their annual Structures conference last week in San Francisco, CA. “But SDN was also deemed not relevant for a variety of use cases, and it was also roundly declared a loser, and something that hasn’t really changed in the years since it has hit the network scene.”
Yet SDN continues to make progress. More and more companies are joining the Open Network Foundation and the Open Daylight consortium. Dan Pitt, executive director of the Open Networking Foundation was quoted elsewhere as saying:
“The broad turnout for implementing OpenFlow 1.3, specifically using merchant silicon, at the PlugFest demonstrated growth in deployment of OpenFlow–based SDN. The successful interoperability testing of OpenFlow 1.3 on hardware switches and controllers is a significant step towards offering our end users interoperable products for accelerated adoption of the OpenFlow protocol and SDN.”
Note: Dan emailed me a comment which he was good enough to revise and post in the Comment box below this article. Hopefully, someone with more knowledge of this subject than me will post a reply comment.
Industry Comments on Cumulus Networks:
Scott Thompson of FBR Research:
“Cumulus Networks opens the floodgates for price compression in network hardware. Cumulus Networks emerged from stealth-mode operation last Wednesday. We view Cumulus as a key strategic piece of the puzzle to enable hyperscale, service provider, and large enterprises to transition to bare metal switching and routing platforms. We view Cumulus as the first truly credible and scalable organization with the expertise necessary to unlock the value of truly commoditized hardware.We view the competitive and strategic threat enabled by CumuIus to have a much greater impact than the direct threat from the start-up itself.”
James Hamilton of Amazon:
“One of my favorite startups, Cumulus Networks, has gone after exactly the problem of making ODM produced commodity networking gear available broadly with high quality software support. Cumulus supports a broad range of ODM produced routing platforms built upon Broadcom networking ASICs. They provide everything it takes above the bare metal router to turn an ODM platform into a production quality router. Included is support for both layer 2 switching and layer 3 routing protocols including OSPF (v2 and V3) and BGP. Because the Cumulus system includes and is hosted on a Linux distribution (Debian), many of the standard tools, management, and monitoring systems just work. For example, they support Puppet, Chef, collectd, SNMP, Nagios, bash, python, perl, and ruby.
Rather than implement a proprietary device with proprietary management as the big networking players typically do, or make it looks like a CISCO router as many of the smaller payers often do, Cumulus makes the switch look like a Linux server with high-performance routing optimizations. Essentially it’s just a routing optimized Linux server.
Cumulus supported platforms include Accton AS4600-54T (48x1G & 4x10G), Accton AS5600-52x (48x10G & 4x40G), Agema (DNI brand) AG-6448CU (48x1G & 4x10G), Agema AG-7448CU (48x10G & 4x40G), Quanta QCT T1048-LB9 (48x1G & 4x10G), and Quanta QCT T-3048-LY2 (48x10G & 4x40G).”
Andreessen Horowitz
“Andreessen Horowitz is betting heavily on the transformation of the datacenter from something that was traditionally hardware-centric to a new world where the intelligence lives in software. Nicira was an investment that addressed a key part of this, and now Cumulus Networks is filling another critical piece on the networking side,” said Peter Levine, Partner, Andreessen Horowitz. “The recent announcement from Facebook’s Open Compute Project underscored this need for a Linux OS for networking. Clearly the need is massive. And the opportunities for enterprises and service providers to drive massive new efficiencies in the datacenter is massive as well.”
VMware:
“There is an emerging network architecture being adopted by enterprises and service providers consisting of intelligent edge software, decoupled from the underlying physical network, running over general purpose network hardware. There are many benefits to this architecture, such as a software operational model and software innovation speeds, but the biggest benefit is customer choice,” said Hatem Naguib, vice president of networking and security, VMware. “Cumulus Linux provides customers more flexibility in choosing the underlying infrastructure used to deploy network virtualization from VMware.”
More information at:
- http://www.reuters.com/article/2013/06/19/ca-cumulus-idUSnBw195271a+100+BSW20130619
- http://searchnetworking.techtarget.com/news/2240186592/Cumulus-Networks-CEO-How-Linux-based-switches-change-network-ops
- http://www.theregister.co.uk/2013/06/20/cumulus_networking_launch/
Conclusions: #
The Cumulus approach is a clear alternative to SDN for open networking. It is compatible with VMware’s network virtualization and Opens Stack’s cloud orchestration software which appear as “applications” that accesses the Linux OS to control the physical network hardware (e.g. “bare metal” commodity switches made by ODMs).
The revolutionary disruptive force here is that the “bare metal” switch/routers must use the Cumulus Networks Linux based Network OS to control their operations and schedule real time tasks. That’s never been tried before in any networking equipment I’m aware of- ever! It remains to be seen how many ODM “bare metal” switches will support this new paradigm rather than use their own proprietary real time Network OS.
The “bare metal” switch/routers from ODMs are ultra low cost and use merchant silicon for switching/routing functions. Those ODMs (with or without a disaggregated Network OS) will threaten the high profit margin L2/L3 switch makers, especially Cisco and Juniper!
It will be very interesting to see how Cisco, Juniper, Brocade, Dell (Force10), and Arista Networks respond to this competitive threat.
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