 up its sleeve. It passes the information of control to any other potential candidate that holds the key to dynamically transform the network like moving packet to greater bandwidth path or more suitable way or improving the Quality of Service settings on the basis of how much free the network is Reliability At the prefatory note, it was mentioned that SDN controller provides an intelligent network that does design validation while configuring the network and hence eliminates manual errors. What all capabilities a controller can provide, it is still degraded in the market for one of the main and important reason and that is, it is a single point failure and hence the controller decreases overall network availability. Therefore, while evaluating controllers, organization has to understand the functionality of controllers in terms of reliability. Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 The Heart and Brain of SDN One popular example for reliable source is the power path software used by DELL EMC to transfer the network to multiple paths if one of them fails. Similar is the scenario for any SDN Controller that is to discover multiple paths between start and destination, the availability of the solution is not impacted by the outage of the link. On the other hand, SDN Controller if sets up a single path between start and end point of the network, if the path fails for whatever reason, should be able to route the traffic to an active link. This can only be satisfied if the controller is monitoring the network continuously. In terms of the availability of the controller itself, it is critical that the controller be built using both hardware and software redundancy features. It is also imperative that the SDN controller enable clustering. For example, clustering two SDN controllers in active/hot standby mode increases reliability and clustering three or more SDN controllers, with one in hot standby mode, increases the availability, scalability and performance of an SDN contro