Network virtualization enabled by Software-Defined Networking, as exemplified by the new OpenFlow standard, promises far-reaching changes in the ICT world. NEC leads the world in the implementation of this new technology
For many operators of data centers, especially those offering cloud services, virtualization technology has brought many benefits. Virtualization 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.
Storage systems have likewise been virtualized, allowing data storage “pools” to be created and allocated on demand, but networking has lagged behind until now, and has been a more static and inflexible component of the data center’s infrastructure.
Open up the Box!
For Hiroyuki Watanabe, General Manager, Enterprise Solutions Operations Unit, “current networking products are basically closed boxes. Computers are now open in that users are able to write applications for them. Networking hardware is currently a closed inflexible architecture, which cannot be changed or modified by the user,” he explains. “Data center operators simply use it and cannot optimize it.”
His vision is to open 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 SDN (Software- Defined Networking). Recent developments have resulted in networks which are more responsive to user needs, whether the user is an enterprise operating its own data center, or an ICT provider supplying cloud services to corporate clients. As capacity is required or becomes redundant, resources can be brought into or taken out of play, thereby maximizing the investment made by an enterprise in its network.
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.
In an OpenFlow network, the switches route network traffic according to the rules set up in a “flow table” inside the switch. Software commands issued from a central controller may be used to rewrite these tables, allowing instant changes to the network architecture. Furthermore, this is an open inter-manufacturer protocol, thus one command set can be used to modify the configurations of hardware from different makers.