Equipment vendors have been attempting to introduce Software-Defined Networking (SDN) equipment to the market over the past two years, which implies there are special hardware features required to create an SDN switch. But still, in reality, some of these new switches are not quite as open, flexible and programmable as they seem on the surface.
Put simply, a switch is either SDN or traditional. The main difference between these two categories is the software called an OpenFlow Agent (OF-Agent), which takes SDN commands coming from the controller and translates them into a language the switch can understand. But many of the “SDN switches” in the market today do not allow the network operators an access to the OF-Agent, making it next to impossible for the operators to change anything about the switch. This can make it unfeasible for companies to use equipment from various vendors, as the implementations of the OF-Agent can vary wildly from vendor to vendor. This reduces interoperability and keeps customers locked in with a specific vendor and its capabilities.
However, for sure, there are also true bare metal switches, where the software and hardware are sold separately, allowing the end-user to load software of their choice, instead of relying on a vendor. Further to that, there are also ways to get around the attempted vendor lock in of the so-called SDN switch. The Open Network Install Environment (ONIE), is an Open Compute Project open source initiative, which defines an open “install environment” for bare metal network switches where end users have a choice among different network OS. By taking over ownership of the software, companies are no longer forced to rely on a specific vendor for software needs and updates. This allows companies to actually control those so-called open SDN switches through software. More importantly, it allows legacy, traditional network systems to migrate to a SDN system without replacing existing hardware and thus offering lower-cost and a more flexible switching alternative.
Open vSwitch(OVS), a production quality open-source software implementation of a distributed virtual multilayer switch, aids in SDN adoption and effective network automation. OVS allows for overlay networking, which is a computer network built on the top of another network. This allows the underlying network to behave in a traditional way and two virtual machines on two different servers to be connected to each other directly by a piece of software.
In conclusion, the future of networking relies more and more on software. Per the November 2014 IHS Infonetics Carrier SDN and NFV Hardware and Software market size and forecast report, revenue from SDN software (orchestration and controller, and network apps) will grow from $46 million in 2014 to $1.7 billion in 2018, with a 2013–2018 CAGR of 185%. Also in 2018, SDN+NFV software is 77% and hardware is 23% of total service provider SDN/NFV revenue. SDN and NFV (Network Function Virtualization) represent the shift of focus from hardware to software. Software is the key that unlocks the capabilities and benefits of SDN for any switch on any network. You just have to know where to look and apply!
Hardware vs Software Revenue, 2018 – IHS Infonetics Carrier SDN and NFV Hardware and Software market size and forecast report, November 2014