A system and method for optimizing Internet data transmission so that end-user experience is the best possible. The invention has at least one class set for estimating the network load, wherein each class set consists of classes. The method estimates the network load by each class of the class set. The estimation may be based on counting retransmission requests or packet acknowledgements related to class sets. For example, a class set may consist of classes so that there is a class per each cell of the network. Then the method detects which packets cause a lot of retransmission requests and thus a lot of retransmissions. The method can intelligently target its acceleration actions to certain packets. Four new acceleration actions can be used together with the prior art acceleration actions to accelerate the network traffic.