Distributed Controller Placement in Software-Defined Networks with Consistency and Interoperability Problems

Table 2

Comparison of controllers.

Controller	Organization	Language	Issue			Multi threading	Capacity	Flow request	Interface
			Consistency	Reliability	Scalability
NOX	Nicira	C++	High	Low	Low	Yes	Small	30 k/s	X
POX	Nicira	Python	High	Low	Low	X	Small	X	X
Maestro	Rice uni	X	X	X	X	X	Small	300–600 k/s	X
Ryu	NTT lab	Python	X	X	X	X	Small	6 k/s	OpenFlow
Floodlight	Big switch	Java	High	Low	Low	X	Small	250 k	X
Beacon	Stanford	Java	X	X	X	Yes	Small	12.8 m/s	OpenFlow