The invention concerns a method of providing a real-time communication connection over an IP communication network between a first entity and a second entity, as well as a sending and a receiving device to execute the method. The basic idea of the invention is to fragment non-real-time streams associated with the real-time communication connection at the first entity, to multiplex the fragments of the non-real-time streams into real-time streams of the real-time communication connection at the first entity, and to transmit the multiplexed real-time streams comprising the real-time streams and the fragments of the non-real-time streams via the real-time communication connection from the first entity to the second entity. In order to ensure a reliable quality of service of the real-time data, the real-time part of the multiplexed data stream is assigned the highest priority for transmission. At the second entity, the multiplexed real-time streams are demultiplexed, the fragments of the non-real-time streams are re-composed and the original non-real-time streams are re-generated.