This master thesis deals with the problems of memory reduction in the stateful network traffic processing. Its goal is to explore new possibilities of memory reduction during network processing. As an introduction this thesis provides motivation and reasons for need to search new method for the memory reduction. In the following part there are theoretical analyses of NetFlow technology and two basic methods which can in principle reduce memory demands of stateful processing. Later on, there is described the design and implementation of solution which contains the application of these two methods to NetFlow architecture. The final part of this work summarizes the main properties of this solution during interaction with real data.