A media server for performing adaptive streaming on media contents to be streamed to a client device, comprising: a transmitter; a receiver; and a processor connected to the transmitter and the receiver, and configured to perform: sending, via the transmitter, to the client device a media presentation description, MPD, file comprising information for specifying streaming adaptation parameters, wherein values of the streaming adaptation parameters are to be provided by the client device; receiving, via the receiver, a request from the client device, the request comprising a data object location indicator and a query string containing values of at least one of the streaming adaptation parameters; selecting, after receiving the request, a data object to be returned to the client device based on at least one of the data object location indicator and the query string of the request; and sending a response with the data object to the client device; characterized in that, the values of the streaming adaptation parameters comprise a segment number and a value indicative of a bandwidth of a network connection between the media server and the client device; wherein, the data object selected in the step of selecting is a segment of a representation of the media contents based on the values of the streaming adaptation parameters, or wherein the data object selected in the step of selecting is a second MPD file, wherein the values of the streaming adaptation parameters comprise a first segment number, and the second MPD file comprises a second segment number corresponding to a segment of an advertisement, wherein the step of selecting the new MPD file comprises determining that the second segment number is before the first segment number in sequence. a transmitter; a receiver; and a processor connected to the transmitter and the receiver, and configured to perform: sending, via the transmitter, to the client device a media presentation description, MPD, file comprising information for specifying streaming adaptation parameters, wherein values of the streaming adaptation parameters are to be provided by the client device; receiving, via the receiver, a request from the client device, the request comprising a data object location indicator and a query string containing values of at least one of the streaming adaptation parameters; selecting, after receiving the request, a data object to be returned to the client device based on at least one of the data object location indicator and the query string of the request; and sending a response with the data object to the client device; characterized in that, the values of the streaming adaptation parameters comprise a segment number and a value indicative of a bandwidth of a network connection between the media server and the client device; wherein, the data object selected in the step of selecting is a segment of a representation of the media contents based on the values of the streaming adaptation parameters, or wherein the data object selected in the step of selecting is a second MPD file, wherein the values of the streaming adaptation parameters comprise a first segment number, and the second MPD file comprises a second segment number corresponding to a segment of an advertisement, wherein the step of selecting the new MPD file comprises determining that the second segment number is before the first segment number in sequence. sending, via the transmitter, to the client device a media presentation description, MPD, file comprising information for specifying streaming adaptation parameters, wherein values of the streaming adaptation parameters are to be provided by the client device; receiving, via the receiver, a request from the client device, the request comprising a data object location indicator and a query string containing values of at least one of the streaming adaptation parameters; selecting, after receiving the request, a data object to be returned to the client device based on at least one of the data object location indicator and the query string of the request; and sending a response with the data object to the client device; characterized in that, the values of the streaming adaptation parameters comprise a segment number and a value indicative of a bandwidth of a network connection between the media server and the client device; wherein, the data object selected in the step of selecting is a segment of a representation of the media contents based on the values of the streaming adaptation parameters, or wherein the data object selected in the step of selecting is a second MPD file, wherein the values of the streaming adaptation parameters comprise a first segment number, and the second MPD file comprises a second segment number corresponding to a segment of an advertisement, wherein the step of selecting the new MPD file comprises determining that the second segment number is before the first segment number in sequence.