Application Programming Interface offering classification services to end-user applications

There are several sophisticated and practically tested technologies supporting Quality of Service (QoS) through a communication network. On the other hand, the extension of QoS support towards end-user applications is quite rare. The Application Programming Interface (API) described in this paper represents a possibility how to extend QoS in this direction under the Microsoft Windows environment. The solution presented is closely related to the DiffServ technology, i.e. packet marking based on the type of the network service the packet was generated by.