There's no question that software-defined networking (SDN) will play a major role in the future of networking equipment...
and IT operations.
SDN is already influencing network planning because of two key attributes. The first of these is a fundamental change in the way networks are designed. By separating the control and data planes in network equipment, SDN lets networks become more flexible, adaptable and dynamic as application demands grow.
Perhaps even more importantly, SDN shifts the focus of networking away from Layers 2 and 3, all the way to Layer 7, creating network functionality based on policy rather than quantitative management-console settings. The traditional (and usually expensive) strategy of simply overprovisioning the network and hoping for the best as traffic demands grow no longer works. We are now living in an era of bring your own device policies, in which every user has multiple devices and demands access to essentially every application, including those with stringent low latency requirements.
The vast majority of this end-user demand for application services is originating on mobile devices connected to the network via Wi-Fi. As a result, it's important to consider the role SDN will play -- and, as we'll see below, is already playing -- in wireless LANs today, and determine how this role will evolve over the next few years. A key issue: Just how much of an SDN-centric implementation is required in next-generation Wi-Fi? Are we looking at yet another forklift upgrade?
Short answer: No. Although the courtship between WLANs and SDN is in its earliest stage, a number of vendors are already moving to ensure their relationship is set for the long term and the existing wireless plant will undergo little disruption.
How wireless vendors are using SDN technologies
I recently spoke with a number of leaders in the WLAN space about their plans for SDN, and this is what I learned:
Aruba Networks -- For Aruba (which has been purchased by HP), SDN serves to simplify network configuration and operations. Its interest is being driven in large part by the deployment of unified communications, in particular for the support of the very popular Skype for Business, formerly known as Microsoft Lync Server. Rather than attempt to manually optimize the time-bounded data flows essential to Lync, users can take advantage of SDN's programmability to achieve the network adaptability and efficiency that today's high-demand WLAN services require.
Cisco Systems -- Cisco's SDN emphasis is on unified wired/wireless networking, centering on its Catalyst 3850 line of switches. The related Cisco Open Networking Environment and Cisco Application Centric Infrastructure are enhanced by the essential programmability of the 3850 line (and the Nexus 9000 series in the case of ACI), and we expect that SDN capability will become pervasive across all of Cisco's enterprise product lines. Of particular interest to enterprises is Cisco's Application Policy Infrastructure Controller Enterprise Module for the Catalyst switches, ASR routers and wireless LAN controllers, which provide automation and management.
Extreme Networks -- Extreme is offering what it refers to as an SDN platform that spans its entire product line, including wireless LAN. The company stresses a single operating system, EXOS, across all of its major hardware products, including OneController, the heart of its SDN efforts. The company places a particular emphasis on NetSight, its management platform, as well as its Purview analytics software, stressing again the need to consider all network components when using SDN. An SDN software developer's kit is also available.
HP -- HP is stressing applications to showcase the value of SDN. Its new Network Visualizer app assists in visibility, diagnostics, troubleshooting and proactive performance monitoring. Network Protector handles security, and Network Optimizer is a quality of service (QoS) engine aimed at education environments. "Mobile-centric networks" is a key theme for HP, with an emphasis on collaboration and unified content sharing.
Meru Networks -- Meru, which is being acquired by Fortinet, noted that it is the first vendor to receive certification under the Open Networking Foundation's (ONF's) OpenFlow Conformance Testing Program, and that seamless interoperability is a major goal for the firm. It's also building next-generation Wi-Fi applications that take advantage of SDN, such as Collaborator, which allows Skype for Business to communicate with a controller, setting higher QoS policies for unified communications sessions. Personal Bonjour lets Apple device users set up a wireless personal area network while ensuring that existing QoS policies are enforced across both wired and wireless networks. Meru also contends that extending SDN to the wireless edge will yield additional major benefits by reducing total cost of ownership.
Every vendor mentioned both OpenFlow and OpenDaylight as key elements in their overall SDN -- and, thus, Wi-Fi -- strategies. Despite their support of these protocols, however, it's too early to expect full and transparent multivendor interoperability. That's due in part to the evolving state of OpenFlow and OpenDaylight and to the highly competitive nature of the networking business overall.
Indeed, SDN protocols beyond OpenFlow may play a significant role over time, and the open source nature of many implementations encourages extensions that may ultimately remain proprietary. Note, however, that SDN extensions to controller-based WLAN implementations do not require any modifications to access points, just software additions to the controller itself. So, no matter what the flavor of SDN supported, it's relatively easy to extend SDN into the WLAN domain. This is a key reason we've already seen so much progress in the next-generation Wi-Fi space.
With so much effort already underway, we expect that all long-term players in enterprise-class Wi-Fi will establish major positions in SDN going forward. And no matter how one defines SDN, it's already clear that successful implementations of SDN will change the network end-to-end -- from access at the edge to the core. And with the edge of organizational networks today being primarily wireless, SDN must play a central role in wireless LAN implementations. Some progress has already been made. The highly motivated vendor community will almost certainly ensure that next-generation Wi-Fi keeps pace with further advances in SDN.
Where SDN and the LAN intersect
SDN has enormous promise for wireless
ONF exploring OpenFlow's potential in wireless network