A computer circuitry for use in a media server operable to provide HyperText Transfer Protocol, HTTP, adaptive streaming, the computer circuitry being configured to: send a server-availability communication to a plurality of clients indicating that the media server will go offline at a specified time; send an upload-rate communication to the plurality of clients to indicate a change in an upload rate for the media server; send a new-server communication to the plurality of clients to indicate when a new server is available, the new server having at least one representation in common with a Media Presentation Description, MPD, file at the media server; and send a MPD-change communication from the media server to the plurality of clients indicating when at least one change has been made to the MPD file at the media server to enable the media server to efficiently deliver the HTTP adaptive streaming; the computer circuitry being further configured to: associate an available representation code, ARC, with the representations that are available on the media server, the ARC comprising a binary string wherein each bit corresponds to a representation that is available on the media server; and to append the ARC to a segment packet to send to a client, to append the ARC as a header to a segment packet to send to a client, to include the ARC in a MPD metafile as an attribute, or to send a value of at least one bit in the ARC to a client via an HTTP Post request to the client. send a server-availability communication to a plurality of clients indicating that the media server will go offline at a specified time; send an upload-rate communication to the plurality of clients to indicate a change in an upload rate for the media server; send a new-server communication to the plurality of clients to indicate when a new server is available, the new server having at least one representation in common with a Media Presentation Description, MPD, file at the media server; and send a MPD-change communication from the media server to the plurality of clients indicating when at least one change has been made to the MPD file at the media server to enable the media server to efficiently deliver the HTTP adaptive streaming; the computer circuitry being further configured to: associate an available representation code, ARC, with the representations that are available on the media server, the ARC comprising a binary string wherein each bit corresponds to a representation that is available on the media server; and to append the ARC to a segment packet to send to a client, to append the ARC as a header to a segment packet to send to a client, to include the ARC in a MPD metafile as an attribute, or to send a value of at least one bit in the ARC to a client via an HTTP Post request to the client. associate an available representation code, ARC, with the representations that are available on the media server, the ARC comprising a binary string wherein each bit corresponds to a representation that is available on the media server; and to append the ARC to a segment packet to send to a client, to append the ARC as a header to a segment packet to send to a client, to include the ARC in a MPD metafile as an attribute, or to send a value of at least one bit in the ARC to a client via an HTTP Post request to the client. <EOS>