For more than a year now, the networking blogosphere has been abuzz about OpenFlow and software-defined networking (SDN). With software-defined networking, engineers can decouple the network control plane from underlying hardware to enable more granular management. They can also dynamically provision virtual switching to support server virtualization environments.
The problem is, while there have been numerous OpenFlow and software-defined networking applications written, many users are awaiting evidence of concrete use case scenarios. They also want to know how dozens of apps written in OpenFlow language will be used across existing networking hardware.
This week at the OpenFlow Symposium hosted by Tech Field Day in San Jose, Calif., data center mega-users Google and Yahoo, as well as networking vendors like Cisco and Brocade, outline how their companies are using OpenFlow and software-defined networking and what must still be done before the technologies experience market-wide uptake.
Watch these videos from their OpenFlow Symposium presentations.
Yahoo on software-defined networking in warehouse-scale data centers
If you can choose your own operating system and software to run on top of server hardware, why can't you do the same on your networking hardware? That's the question Yahoo principal architect Igor Gashinsky poses during his OpenFlow Symposium presentation. Networking today, he says, is like running mainframe, where you get a big box and no choice of software. Software-defined networking changes all of that, creating an ecosystem of software players, including OpenFlow. Once the control plane is decoupled from the network, hardware no longer has to spend its CPU doing things like topology discovery. The result is cost and power efficiency in addition to the ability to spin innovation in management.
Watch Gashinsky’s presentation on the use of SDN and OpenFlow in networks that support warehouse-scale data centers.
Google: Software-defined networking means energy efficiency and more
Ed Crabbe of Google would like the world to know that software-defined networking and OpenFlow are not exactly new. In fact, he says, they're manifestations of technology such as PCE, which h been around for years. With this background and further development, Crabbe says moving intelligence off of the network hardware is resulting in more effective use of network resources and can result in other efficiencies, including energy reduction.
Here's what Crabbe has to say about how software-defined networking can play a role in savings and network innovation.
Cisco on software-defined networking: Distributed firewalls, adaptive monitoring and more
Cisco distinguished engineer David Meyer says the 10,000-mile view of SDN is the ability to go faster, cheaper and better -- not two of the three, which is what most engineers are accustomed to. But more specifically, he says that SDN enables extraction of forwarding, distributed state andcontrol, as well as a centralized view of the network and the ability to decouple policy from configuration. What does this mean? Among the potential SDN use cases, Meyer lists dynamic access control, implementation and management of distributed firewalls, energy proportional networking, adaptive network monitoring and more.
Here's what Meyer has to say about software-defined networking use cases.
Brocade in OpenFlow: Lots of promise, but how about some expectation control?
OpenFlow may have lots of promise, but expectation management is in order, according to Curt Beckmann, principal architect at Brocade. While some see OpenFlow as comparable to the x86 instruction set, Beckmann sees it more as the kernel API. While that opens lots of opportunities in development, just as much work must be done in compiling OpenFlow or SDN language for use across existing hardware.
Here's what Beckmann has to say about the promises and challenges of software-defined networking.
Big Switch Networks: Software-defined networking crucial for server virtualization
If VMware can virtualize servers, then Big Switch can virtualize switches, according to Kyle Forster of Big Switch Networks. He says that Big Switch enables the dynamic creation of virtual switches and network infrastructure so that provisioning a simple VM doesn't take two weeks. Big Switch sees software-defined networking as three tiers: the dataplane, the controller and the application. Big Switch focuses on the two latter tiers.
Here's what Forster has to say about the role of software-defined networking in virtualization.
Enterprise Strategy Group analyst: Jury is still out on OpenFlow
Enterprise Strategy Group's John Olstik says massive shops will move toward software-defined networking and OpenFlow, but he has concerns about whether “an external controller can really scale to provide control path guidance for a massive network.”
Here are Olstik's doubts on OpenFlow and software-defined networking in this Enterprise Strategy Group blog.
OpenFlow could disrupt the networking market given a little development
OpenFlow has the potential to disrupt the networking industry and further commoditize network switches, but that will take some technical development, according to Packet Pushers host and blogger Ethan Banks. From the OpenFlow Symposium, Ethan gathered that the OpenFlow 1.0 spec is immature but bugs are likely to be worked out in OpenFlow versions 1.2, 1.3 and 1.4, which are currently being developed. Also, specific applications of OpenFlow are currently fuzzy, though many seem to be focused on using the technology for traffic forwarding that enables engineers to specify criteria for frames or packet. Banks suggests the “magic will come” when vendors begin writing applications that “inform the controller in clever ways.”
Read Ethan's take on the development of OpenFlow and whether it could play a role in commoditizing network switches even further.