Network virtualisation enabled by software-defined networking, as exemplified by the new OpenFlow standard, is expected to have significant impact on the information and communication technology space.

For many companies operating data centers, especially those offering cloud services, virtualisation technology offers several benefits. Virtualisation allows one physical server to act as if it were many machines, and when demand is heavy, many servers can be clustered and act as one computer.

Similarly, storage systems have been virtualised, allowing data storage "pools" to be created and allocated on demand, but networking has been a static and inflexible component of data center infrastructure.

Open up the Box!

Industry experts say that current networking products are basically closed boxes. Computers are now open, implying users are able to write applications for them. Networking hardware is currently a closed and inflexible architecture, which cannot be changed or modified by the user.

Data center operators simply use it and cannot optimize it. The solutions then lies in opening up the hardware used in networks, allowing custom applications to be run on it, increasing its responsiveness, flexibility, and efficiency. Such a network, where the functionality is configured and controlled via software, rather than its physical configuration and deployment, provides software defined networking (SDN). OpenFlow, an open source SDN protocol, provides a platform on which such an open architecture can run, making networks as flexible as the rest of the data center, and able to respond to the changing demands. For example, a data center housing many tenants may need to change a network's topology as new tenants are added, or as the demands of existing tenants change.

Go with the (Open) Flow

At the end of 2006, Stanford University's Professor Nick McKeown proposed an initiative to implement SDN, resulting in the development of the OpenFlow protocol above, which has since been ratified as an inter-manufacturer standard, with the Open Networking Foundation having 89 members as of February 2013.

OpenFlow is "open" in two senses: firstly, it is an open, inter-manufacturer standard, allowing common control of networking equipment, regardless of the maker. Secondly, it “opens the box" in the sense that-it is possible for the user of OpenFlow equipment to get "under the hood" and control the flow of data through the network.

Proven Customer Benefits

Open flow technology brings about considerable savings in capital expenditure and operational expenses (CAPEX and OPEX. It is estimated that for a 1,000-server data center, both capital and operational expenditure can be reduced by 50 per cent, compared to conventional networks.

It is expected that the future users of SDN will be enterprise-level data centers, and communications carriers. Experts believe that the latter will witness several benefits from the same. For example, a significant event may spike an increase in voice and SMS traffic and a possible overload of the system.