- A TechNote on The Next Generation
- Jim Metzler
- Distinguished Research Fellow and Co-Founder
- Webtorials Analyst Division
Software-defined networking (SDN) is one of the hottest topics in IT. While few vendors are aggressively shipping products that support SDN, most of them are scrambling to develop strategies-- and for good reason: SDN has the potential to fundamentally change networking.
Technology Promise vs. Delivery
Of course, if we look back in time, a number of technologies (and ways to deliver services) promised to fundamentally change IT, but many of them either did not deliver or made their real impacts a decade or more after we first heard about them. Take Application Service Providers (ASPs) for instance. It's easy to argue that ASPs have made a huge impact on IT now that they have changed their delivery model and rebranded themselves as "Software-as-a-Service" providers. But we first heard about ASPs' "great promise" roughly fifteen years ago.
Today the "great promise" of SDN should probably be viewed through the record of other technologies that came before. IT organizations should critically assess SDN with questions like: "What are vendors saying about SDN?", "Are all approaches to SDN basically the same?" and "What value does SDN offer my company now?" The next two TechNotes will partially address the first two questions, and future TechNotes will further analyze SDN technology.
For the purpose of the next two TechNotes, we will define software-defined networking as the separation of network-data-traffic processing from the logic and rules controlling the flow, inspection and modification of that data. With SDN, traffic-handling is a distinct software application, but packet processing is handled in hardware. SDN-optimized switches (in theory) can be relatively simple devices based on commodity ASICs (so-called "merchant silicon") as opposed to expensive proprietary chips.
The Value of Direct Programmability
Extreme Networks is one of many vendors who made recent SDN announcements. Specifically, they:
And while Cisco's latest Open Network Environment (ONE) announcement has generated a lot of interest in the direct programmability of network switches, Extreme actually made related announcements back in December 2008. These included:
So "direct programmability" has actually been around for a few years now.
Extreme adds that a key enabler of effective SDN is the network operating system that's in the switches. The company feels that network operating systems must provide the right APIs to support both OpenFlow as well as traditional applications, and that they need to provide proper network abstraction. Also, having a single operating system running across all SDN switches will make application development and debugging faster. For all these reasons, Extreme believes that XOS differentiates the company's SDN value proposition from those of other vendors.
My next TechNote will continue our discussion of SDN, with more detail about Cisco's Open Network Environment (ONE) announcement.
Technology Promise vs. Delivery
Of course, if we look back in time, a number of technologies (and ways to deliver services) promised to fundamentally change IT, but many of them either did not deliver or made their real impacts a decade or more after we first heard about them. Take Application Service Providers (ASPs) for instance. It's easy to argue that ASPs have made a huge impact on IT now that they have changed their delivery model and rebranded themselves as "Software-as-a-Service" providers. But we first heard about ASPs' "great promise" roughly fifteen years ago.
Today the "great promise" of SDN should probably be viewed through the record of other technologies that came before. IT organizations should critically assess SDN with questions like: "What are vendors saying about SDN?", "Are all approaches to SDN basically the same?" and "What value does SDN offer my company now?" The next two TechNotes will partially address the first two questions, and future TechNotes will further analyze SDN technology.
For the purpose of the next two TechNotes, we will define software-defined networking as the separation of network-data-traffic processing from the logic and rules controlling the flow, inspection and modification of that data. With SDN, traffic-handling is a distinct software application, but packet processing is handled in hardware. SDN-optimized switches (in theory) can be relatively simple devices based on commodity ASICs (so-called "merchant silicon") as opposed to expensive proprietary chips.
The Value of Direct Programmability
Extreme Networks is one of many vendors who made recent SDN announcements. Specifically, they:
- Will support OpenFlow across all of the firm's Ethernet switch products.
- Are adding NEC OpenFlow to the controllers they support.
- Are expanding their SDN strategy with support for OpenStack Quantum via plug-ins.
- Announced an Xkit development portal that will enable the creation of SDN development communities.
And while Cisco's latest Open Network Environment (ONE) announcement has generated a lot of interest in the direct programmability of network switches, Extreme actually made related announcements back in December 2008. These included:
- ExtremeXOS SDK, which allows third-party programs to interface with Extreme switches through an extensive XML API and SDK.
- Tools for programmers to write applications that run directly within XOS (the operating system for Extreme switches).
- SDK support for third-party applications that run as binary images on XOS.
So "direct programmability" has actually been around for a few years now.
Extreme adds that a key enabler of effective SDN is the network operating system that's in the switches. The company feels that network operating systems must provide the right APIs to support both OpenFlow as well as traditional applications, and that they need to provide proper network abstraction. Also, having a single operating system running across all SDN switches will make application development and debugging faster. For all these reasons, Extreme believes that XOS differentiates the company's SDN value proposition from those of other vendors.
My next TechNote will continue our discussion of SDN, with more detail about Cisco's Open Network Environment (ONE) announcement.
