Introducing Software Defined Networks

Software-defined networking (SDN) is an approach to networking in which control is decoupled from hardware and given to a software application called a controller. That was created in response to demands from large data centers that have rapid changes in the network load.

• Directly programmable: Network control is directly programmable because it is decoupled from forwarding functions.
• Agile: Abstracting control from forwarding lets administrators dynamically adjust network-wide traffic flow to meet changing needs.
• Centrally managed: Network intelligence is (logically) centralized in software-based SDN controllers that maintain a global view of the network, which appears to applications and policy engines as a single, logical switch.
• Programmatically configured: SDN lets network managers configure, manage, secure, and optimize network resources very quickly via dynamic, automated SDN programs, which they can write themselves because the programs do not depend on proprietary software.

However, that  technology is new and only a few companies can offer it. That is because in order to implement it, the companies have to upgrade their resources and teach the staff how to work with SDN.