The UPnP Media Renderer
UPnP Media Renderer's software implementation
AVTransport
This class is an implentation of the UPnP AVTransport service. On one side it interacts with the AudioPlayer class by invoking the methods of the player. On the other side its methods are called by the main class when the actionControlReceived method receives a SOAP request containing an action that corresponds to the AVTransport service. For more details you can look at the source code of the main class of the renderer into the Control section (AVTransport actions).