GravCPA: Controller Placement Algorithm Based on Traffic Gravitation in SDN

Table 1

An overview of current controller placement approaches and the proposed approach.

Author	Objective(s)	Method	Tool(s)	Evaluation
Yao et al. [5]	The SC-wst	LP	Capacitated K-center	Fewer number of controllers, but is complex for large-size networks
Sallahi et al. [6]	Network cost	ILP	Linear solver	High complexity, only for the small size networks
He et al. [7]	Flow setting time	MILP	Gurobi [8]	Moderate complexity
Fan et al. [9]	Control latency and reliability	Modularity	Louvainand PSO [10]	Low complexity, but has subdomain disconnection problem
Traag et al. [11]	Control latency	Modularity	Leiden	Low complexity, fix the problem of the Louvain algorithm
Chen et al. [12]	The SC-avg or SC-wst	Modularity	Louvain, traverse search	Moderate complexity, well-done for subdomain division
Liu et al. [14]	Load balancing and stability	LPA	K-median	Much low complexity, but is bad for subdomain division with traffic
The proposed	The SC-avg and SC-wst	LPA	Heuristic algorithm	Much low complexity and is good for both SC-avg and SC-wst