The present disclosure relates to providing a quality of service (QoS) function for communication services in communication networks. The disclosure presents a device for providing a QoS function, for a communication service of an application entity in a communication network comprising a plurality of network entities. The device is configured to transmit a monitoring request to one or more of: the application entity, a network entity, and a user equipment (UE), obtain a monitoring response from one or more of: the application entity, the network entity, and the UE, determine a change in QoS of the communication service of the application entity, based on the obtained monitoring response, and transmit the determined change in the QoS to the application entity and/or at least one of the network entities in the communication network.