Dozens of companies are now offering SDN-related products—so many that buyers may find it difficult to separate the hype from the meat. In this article, we’ll look at categories of SDN products and how each of them fits into an overall SDN solution.
The key components of an SDN solution are ASICs, switches, a controller, and the applications or services that run over the network.
ASICs have a long history in networking by driving scale and performance. In a clock cycle, very complex tasks can be accomplished. Without the ASIC, the main CPU would be overwhelmed in performing those same tasks (remember those so called “one-arm routers”). The need for ASICs created a new set of suppliers such as Broadcom, Marvell and Mellanox, and most recently Intel through its acquisition of Fulcrum. We can expect more and more specialization in ASICs as the industry pivots on the SDN theme. Over the last decade, the merchant silicon vendors have diversified and specialized products for vertical markets. For example, an ASIC optimized for the data center might have VxLAN support, whereas another tuned for a carrier application might possess rich features for MPLS support.
Switches handle the work of directing network traffic to various end points. Switch vendors implement protocols that enable their switches to communicate with an SDN controller, which tells the switch how to direct traffic. Most of the following vendors are traditional switch vendors, with the exception of Accton and Quanta Computer, which provide bare-metal switches without an OS. Big Switch, Broadcom and Pica8 are exceptions, as they provide a network operating system that is loaded onto a commodity bare-metal switch. Vendors in this space include:
- Big Switch
- Extreme Networks
- Quanta Computer
SDN controllers are the brains of the SDN solution—the place where the user interacts with the network. SDN controllers tell switches how to direct traffic according to policies the user sets. Although OpenFlow is not the only SDN-controller protocol out there, it’s the most visible one. It’s worth noting that in a recent survey by Dr. Jim Metzler of Webtorials Analyst Division, 43 percent of IT managers surveyed said their SDN solution will likely or definitely include OpenFlow, whereas only 3 percent said it would not include OpenFlow. The following vendors provide SDN controllers.
- Big Switch
- Cisco (through ACI/Insieme)
- NTT Labs & NTT Data
- Nuage Networks
- Open Daylight Consortium
Network Applications and Services
The members of this category provide network services and applications such as security and optimization that are part of an overall SDN solution. Rather than simply directing traffic, these applications process traffic with firewall, load balancing or other applications. Vendors include the following:
- Big Switch
- Cisco (through ACI/Insieme)
- Citrix (Netscaler)
- F5 Networks
Over Layer Versus Under Layer
Another way to look at the SDN ecosystem is to segregate products into the over layer and the under layer. The under layer, or physical network infrastructure group of vendors, are all about the network fabric itself. A vendor might deliver the solution in a white box, or it might be a legacy vendor with its own hardware design. Nonetheless, the vendor cares about routing/switching/management and provisioning the network itself. A switch or application might support OpenFlow. Under-layer vendors include Cisco, Cumulus, Extreme, HP, IBM, the Open Daylight Consortium and Pica8.
The over layer, or virtual network infrastructure group of vendors, focuses on building tunnels (also called overlays) and also building virtual network function capability into those tunnels. For example, the user may want to create a tunnel through the network to connect two isolated domains without changing the under layer, and the user may want to spin up a firewall on that tunnel. These solutions are delivered on an x86 server platform—the belief is that the application can scale here through all of those multicore CPUs on a server. Over-layer vendors include the companies in the Network Applications and Services category above.
Open Versus Proprietary Solutions
A final way to look at the SDN ecosystem is to separate vendors into open versus proprietary. Legacy switch vendors have large revenue streams and customer bases to protect, so they tend to offer proprietary solutions that lock the user in. Proprietary vendors include Cisco, HP and IBM, while open vendors include Big Switch and Pica8.
Traditional networking vendors have tightly coupled software and hardware, which imposes unique operational frameworks for each vendor and creates a “one vendor, end-to-end topology” sales mantra. The SDN movement is challenging this idea. The idea of software leading and hardware following also raises fears of hardware commoditization. The best approach is to exploit the degree to which any technology commoditizes, use that as a competitive advantage and then add specific differentiation where customers see value.
SDN promises customers a more consistent operational framework regardless of the network vendor (and hardware). Sure, it leaves the door open for vendors to specialize as well through custom programmability, but let’s consider what the data center world looks like once we have one “control” standard and therefore one common way of operating multivendor networks.
In this data center world, the idea that one vendor provides an end-to-end network will go the way of VHS players and fax machines. In an end-to-end environment, you can buy off on the idea that that your operational environment will be simpler, ostensibly owing to lower training and operational costs, but on many levels, end-to-end has not delivered consistency. Feature differences emerge between product families, driven by ASIC differences; there are OS and CLI differences across product families; and there are architectures across product families that are inconsistent. Clearly, the more we can abstract the operational details from the hardware, the more we will truly deliver on open SDN—and deliver the benefits of a common operational environment end to end.
This change is being backed up by survey data. In the Webtorials survey, over 48 percent of respondents cited openness of the solution as either extremely or very important, while just 7.4 percent cited it as not important.
It’s encouraging to see growing industry support around the idea of being more open, as indicated by increasing support of OpenFlow. The OpenFlow protocol (driven by the Open Networking Foundation) is gaining momentum. Members that represent the customer voice include Deutsche Telecom, Facebook, Google, Microsoft, Verizon and Yahoo. On the vendor side, Cisco, HP and IBM all talk about supporting OpenFlow on portions of their switching portfolios.
The continuing emergence of OpenFlow and SDN promises to change the meaning and the benefit of “end to end.” Vendors will no longer dictate terms through their respective suite of products. Instead, open standards will drive consistency and value as well as lower costs.
So although the SDN market is characterized by vendors offering open and closed approaches, the future points toward broad adoption of OpenFlow and related technologies, and that means greater choice and more control for end users.
About the Author
Steve Garrison is Vice President of Marketing for Pica8. He leads go-to-market and brand development strategies and is a networking-systems veteran with nearly 20 years of technology marketing experience. Steve has held global marketing positions at public and venture-backed companies, including Infoblox, Force10 Networks (acquired by Dell) and Riverstone Networks (acquired by Alcatel-Lucent). He holds an MS in materials science engineering from MIT, and a BS in ceramic science and physics from Alfred University.