What is Control Point?

The role of a control point is to discover all devices that the control point can control and provide an interface for the control of the discovered devices. An AV control point will provide a method of browsing a media server's catalogue of media and will perform all the necessary setup tasks to enable a user defined media renderer to playback the selected media.

Read more at https://oss.linn.co.uk/trac/wiki/UPnP