A method performed by a server of a communication network for making an HTTP media stream accessible to a client, the method comprising: - generating an Media Presentation Description, MPD, such that it is provided with at least two period elements, sequentially arranged according to a media play timeline; such that each period element is provided with at least one representation and such that at least one of the period elements is provided with at least two alternative representations, wherein each representation is provided with an ordered sequence of at least one media segment URI, wherein each media segment URI is referencing at least one media segment of said HTTP media stream, wherein: one of the at least one representation in a first one of the at least two period elements is not one of the at least one representation in a second one of the at least two period elements, and that the method further comprises: - providing the Media Presentation Description, thereby enabling for said client to acquire the MPD; to select, on the basis of said content of the Media Presentation Description, for each of said at least two period elements, a representation and to acquire, for each selected representation, the respective referenced media segments. - generating an Media Presentation Description, MPD, such that it is provided with at least two period elements, sequentially arranged according to a media play timeline; such that each period element is provided with at least one representation and such that at least one of the period elements is provided with at least two alternative representations, wherein each representation is provided with an ordered sequence of at least one media segment URI, wherein each media segment URI is referencing at least one media segment of said HTTP media stream, wherein: one of the at least one representation in a first one of the at least two period elements is not one of the at least one representation in a second one of the at least two period elements, and that the method further comprises: - providing the Media Presentation Description, thereby enabling for said client to acquire the MPD; to select, on the basis of said content of the Media Presentation Description, for each of said at least two period elements, a representation and to acquire, for each selected representation, the respective referenced media segments. one of the at least one representation in a first one of the at least two period elements is not one of the at least one representation in a second one of the at least two period elements, and that the method further comprises: - providing the Media Presentation Description, thereby enabling for said client to acquire the MPD; to select, on the basis of said content of the Media Presentation Description, for each of said at least two period elements, a representation and to acquire, for each selected representation, the respective referenced media segments. - providing the Media Presentation Description, thereby enabling for said client to acquire the MPD; to select, on the basis of said content of the Media Presentation Description, for each of said at least two period elements, a representation and to acquire, for each selected representation, the respective referenced media segments.