This paper deals with the performance comparison of two python-based Software Defined Network (SDN) controllers i.e. POX and Ryu under different network topologies such as Single, Linear, Tree, Dumbbell, Data Center Networks (DCN) and Software-Defined naval networks which use satellite communication systems (SATCOM) i.e. SDN-SAT [1]. Experimental results, validated through Mininet has clearly indicated that Ryu has superior performance i.e. A TCP throughput increase of 25.56%, 282.54%, 44.85%, 19.88%, 45.45% and latency decrease of 93.48%, 99.96%, 99.90%, 97.08%, 99.33% in single, linear, tree, dumbbell and DCN topologies respectively. Similarly, in SDN-SAT topology Ryu has 0.21% increase in TCP throughput and 34.62% decrease in latency as compared to POX controller.