While OpenFlow has received a considerable amount of industry attention, it is worth mentioning that the idea of programmable networks and decoupled control plane (control logic) from data plane has been around for many years. The Open Signaling (OPENSIG) working group initiated a series of workshops in 1995 in order to make ATM, Internet, and mobile networks more open, extensible, and programmable. Motivated by these ideas, Internet Engineering Task Force (IETF) working group came up with General Switch Management Protocol (GSMP) to control a label switch. This group officially concluded and GSMPv3 was published in June 2002.
The active network initiative proposed the idea of a network infrastructure that would be programmable for customized services. However, the active network never gathered critical mass, mainly due to the practical security and performance concerns. Starting in 2004, the 4D project (http://www.cs.cmu.edu/~4D/) advocated a clean slate design...