A file server delivers media files in unicast mode to a media gateway device in response to user requests, and a FCAST/NORM media streamer delivers a stream of these media files in multicast mode to the media gateway device. By using a file server operating in unicast mode and a FCAST/NORM media streamer delivering a stream of these media files in multicast mode, it is possible to switch seamlessly between the two modes in an embodiment. In an embodiment of the invention, a media gateway device includes a cache memory for storing media files from the file server and/or the FCAST/NORM media streamer; and a controller that controls delivery of media files from the cache memory to the user and transmits user requests for media files to the file server when the cache memory does not contain the media files requested by the user. Thus, the controller requests media files from the file server only when the media files requested by the user are not cached. Otherwise, the media files requested by the user are fetched from the cache memory for delivery to the user. In this manner, the media files requested by the user will be delivered by the file server in unicast mode only when the FCAST/NORM media streamer has not supplied such files to the gateway device for caching.