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

Table 1

Comparison of related papers.

Ref	CPP	Controllers interoperability via EWi	Controllers consistency	Study focused, scope, and solution classification
[4]	√	X	X	Controllers’ capacity and traffic condition
[13]	√	X	X	The multicontrol plane from a design logic perspective
[14]	√	X	X
[15]				In-band and out-band solutions
[16]				Design principles and architecture
[17]	√	X	X	Performance metrics, such as latency, reliability, cost, and MOO
[18]	√	X	X	Performance metrics, such as latency, reliability, cost, and MOO
[19]	√	X	X	Classify CPP based on optimization/performance objectives and wireless environment
[20]	√	X	X	Focused on the solution algorithms or approaches used to optimize the well-known CPP performance objectives
[14]	√	X	X	Performance metrics
[21]	√	X	X	Taxonomy of CPP optimization
[22]		X	√	Scalability, consistency, reliability, and security
[23]	X	X	√	The paper focused on works of ensuring consistency at the DP device forwarding state only. It did not cover works focused on CP with multiple controllers. Where the controllers state whether consistent or not at the time of installing the rules entries in the DP switch flow table influence network behaviour
Current document	√	√	√	Controller placement (for resilience, load balancing, application environment, and security), heterogeneous controllers interoperability, and consistency problems