SDN vision points to simpler, cheaper networks

The advent of software-defined networking (SDN) has the potential to revolutionise enterprise networks by slashing the complexity and costs of network administration. Traditionally, networks have been based on a simple concept: that the intelligence to control data flows is embedded in switches and routers. When control rules needed to be changed, administrators either made changes directly on the devices, or had a switch vendor write a change into the software – often taking months. In a sprawling network, the complexity and costs of such changes escalate quickly.In contrast, SDNs are designed to centralise in software-based controllers and much of the network intelligence is found in switches and routers. Administrators can program and manage networks from a centralised console without heed to the underlying hardware. As a result, IT can build more flexible and dynamic networks that are easier to programme, less complex and less costly.SDN has been touted as the force that will commoditise network switch vendors, making underlying hardware irrelevant by abstracting control from the devices. Yet leading vendors believe SDN will open up and accelerate opportunities for leadership, differentiation and innovation in the switch market.Switch it up

It will not be easy to build a resilient SDN-controlled network infrastructure that enterprises feel comfortable using. Even without the control plane, switches still need to deliver high levels of availabilityand performance, since capabilities like failover, link aggregation and self-healing automatic process restart must be handled at device level.

So SDN is not expected to kill network switch vendors. Instead, we see the industry evolving along two distinct paths. In the first, network vendors will continue to build switches and fabrics that simplify and automate network functions. In the second, vendors will build a portfolio of switches - from core to edge - specifically optimised for SDNs yet capable of performing at high levels. In both cases, switch innovation will be essential.

Many core concepts of SDN, like centralised control, are already incorporated in leading vendors’ products. At least one network operating system has open APIs that allow central control and integration with security and other appliances. Interoperability among vendors is another key factor, and a dedication to open standards and interoperability is essential, preferably supporting the OpenFlow protocol and OpenStack Quantum initiatives.

While a complete industry transformation to SDN-enabled networks will likely take years, companies are starting to prepare their networks. In order to migrate to SDN, switches need to support both traditional functionality and SDN protocols – the most popular being OpenFlow. Straddling both traditional switching and SDN capabilities will add complexity to switch design, and only proven network vendors can deliver the innovation required.

Finally, SDN will likely provide opportunities for switch vendors to differentiate themselves. The leaders have already adopted SDN, productising OpenFlow in a generally available and supportedrelease. As customers transition to SDN, the vision will not change: offering customers maximum choice by deploying the architecture that best suit their business needs.

John Gonzalez is ANZ manager for Extreme Networks which delivers network-powered innovation backed by service and support.