Houston, we have a problem! Basically, we've created a situation over the last few years wherein our computing has become virtual and dynamic, but our networking architecture remains static. So, we can initiate Microsoft SharePoint on a virtual machine in a hour, but we can't bring up the bandwidth needed to run it during the same window of time. This is a simplistic example, but it underscores the point: We need a new network that can respond to the variable demands for connectivity and capacity. It needs to be programmable and elastic. It needs to be intelligent and application-aware. It needs to be virtualized not unlike servers and storage are today. And, for many, it needs to be based on software-defined networking (SDN).
Identified by Gartner Inc. as a top 10 strategic technology trend for 2014, SDN is an up-and-coming architecture that separates the control plane from the data plane in networking equipment, so that network intelligence and state are logically centralized, and the underlying network infrastructure is abstracted from applications.
In other words, SDN brings a similar degree of agility to networks that abstraction, virtualization and orchestration have brought to servers, Gartner analyst Joe Skorupa explains in a March 25, 2013, blog. The key takeaway is that SDN enables scalable and flexible networks that adapt to changing business needs.
"SDN's ability to decouple network logic and policies from underlying network equipment allows for a more programmable network," said Rohit Mehra, vice president of network infrastructure at research firm International Data Corp (IDC). "Providing better alignment with underlying applications, this programmability allows for greater levels of flexibility, innovation and control in the network. Logic and policies that can be defined, changed and modified result in a more dynamic network, providing the scale network administrators so desperately crave."
This promise has gained the attention of enterprises and service providers as well as their incumbent networking vendors and a slew of startups like Big Switch. There are even several open source industry projects, such as OpenFlow and OpenDaylight, focused on developing protocols and platforms supporting SDN (see the special section, Open Source SDN Projects, following this article).
Infonetics Research said among the vendors shipping SDN products in 2013 were Alcatel-Lucent, Big Switch, Brocade, Cisco, Cumulus, Dell, Extreme, HP, Huawei, IBM, Juniper, Midokura, NEC, Pica8, Plexxi, Plumgrid, VMware and more. The few early deployments for SDN, including those by Google, NTT, AT&T, Verizon, DT, BT and China Mobile, are in large data centers of cloud service providers and large enterprises, the research firm said.