SDNs networks opt for a centralized approach, in which the controller is the element that defines the overall network management policy and communicates it to openflow switches via the OpenFlow protocol whenever it is requested by them or he considers it opportune. This has a strong impact on latency and packet loss, parameters that have very important for multimedia applications. To optimize the transmission delay in data networks with SDN, two approaches are generally proposed; a responsive approach and a proactive approach. However, we notice that the reactive approach, even if it allows to better evaluate the quality of the optimal paths, increases the latency time. While the proactive approach strongly reduces this time, but does not consider parameters such as the failure of a node on the transfer path. We will propose in this document a mixed approach based on the back-pressure algorithm which is proven as an optimal routing algorithm and rate planning. The aim is to optimize the routing functions by simply placing the traffic where the capacity allows, to avoid congestions of some parts of the network strongly solicited.