SDN: Why It Matters and How Enterprises Can Benefit From It
Sponsored by IBM.
To understand why software-defined networking (SDN) is increasingly relevant, one needs to consider why networks exist in the first place: to provide connectivity and to deliver business-critical applications to valued stakeholders, including employees and customers. Indeed, the changing nature of application workloads has placed unprecedented demands on network infrastructure, especially in the data center.
Traditional data center network architectures were designed to accommodate client/server applications residing on physical servers in a world of single tenancy and relatively predictable north-south traffic patterns. They were not designed for virtualized applications with east-west (server-to-server and rack-to-rack) traffic flows, virtual machine (VM) mobility and multitenancy. Virtualization clearly exposed the limitations of traditional networking, but cloud computing and mobility made those limitations untenable.
In this context, the rise of SDN, initially driven by the needs of large cloud service providers, was inevitable. SDN arose — some would say belatedly — as an architectural approach for networking in the cloud era, capable of delivering the automated provisioning, the network programmability, the network security and visibility and the integration with cloud orchestration systems that organizations require as they pursue digital transformation.
In the latest iteration of IDC’s annual Worldwide SDN Survey, enterprise and cloud service provider respondents were asked to indicate factors that served as their primary motivation for SDN implementation. The need for the network to offer greater agility for virtualization and cloud computing was cited most often (30.7 percent) as the primary motivation by cloud service providers, while 28.7 percent of enterprise respondents specified data center security (including microsegmentation) as a primary SDN motivation.
Even among enterprise respondents, however, the need for the network to possess greater agility for virtualization and cloud computing was referenced by 23 percent of respondents as their primary motivation for implementing SDN. The need for automation and programmability also was cited frequently (just under 23 percent by both enterprises and cloud-service providers).
While SDN holds the promise of delivering cost savings in both OpEx and CapEx, most of the near-term cost savings will continue to accrue to OpEx. Large cloud providers have reported that they have derived notable operational savings from SDN rollouts by gaining improved control of virtual and physical resources; through automated provisioning, configuration and management of the underlying network infrastructure; and through unprecedented operational agility and “service velocity.”
On the CapEx side, the picture is more nuanced. Still, enterprises that have adopted SDN have realized both OpEx and CapEx savings. In IDC’s recent Worldwide SDN Survey, about 50 percent of enterprise respondents reported OpEx savings of 10 percent to 20 percent from implementing SDN. Approximately 31 percent of respondents reported OpEx savings of 21 percent to 30 percent, while just 11.5 percent of respondents reported savings of less than 10 percent.
Even on the CapEx side, many enterprise respondents to IDC’s Worldwide SDN Survey reported notable savings. About 43 percent of respondents that indicated they had deployed SDN reported CapEx savings of 10 percent 20 percent, while approximately 30 percent of respondents estimated their SDN-related CapEx savings ranged from 21 to 30 percent.
SDN’s business extends beyond simple calculations of CapEx and OpEx savings. Indeed, enterprises that properly deploy and manage SDN can realize “time to service” and “time to revenue” benefits resulting from SDN’s automation and SDN’s ability to expedite network provisioning in support of key applications. Improved data center security, often resulting from microsegmentation of server-to-server east-west application traffic, also offers qualitative and quantitative business benefits.
Enterprises shouldn’t perceive SDN as merely a vehicle for the next network refresh or upgrade. Instead, they should view SDN as a means of bringing the network up to speed with the agility advances that have already been achieved in compute and storage as a result of virtualization. Properly implemented and managed, SDN brings automation, programmability, orchestration and visibility to the next-generation data center networks that will be responsible for delivering next-generation applications and services.