A system, comprising: a virtual meeting room, which in operation, accepts from a plurality of participants to a video conference a plurality of audio and video streams from a plurality of video conference endpoints each associated with one of the plurality of participants, characterised in that the system further comprises: a globally distributed infrastructure that supports operations of the VMR, the globally distributed infrastructure comprising a plurality of multipoint control units (MCUs) as media processing nodes, each MCU configured to process the plurality of audio and video streams from the plurality of video conference endpoints in real time, wherein the MCUs are clustered to achieve unlimited scaling and are built from off-the-shelf components instead of custom hardware, and wherein at least one of the media processing nodes comprises an audio transcoder, which in operation, (i) determines a sampling rate to mix audio based on the video endpoints associated with the participants in the VMR, (ii) estimates noise on each audio stream so as to determine the audio streams that are active, (iii) only voice active audio streams are mixed and equalized to reduce noise in the VMR, the mixing being performed at the determined sampling rate. a virtual meeting room, which in operation, accepts from a plurality of participants to a video conference a plurality of audio and video streams from a plurality of video conference endpoints each associated with one of the plurality of participants, characterised in that the system further comprises: a globally distributed infrastructure that supports operations of the VMR, the globally distributed infrastructure comprising a plurality of multipoint control units (MCUs) as media processing nodes, each MCU configured to process the plurality of audio and video streams from the plurality of video conference endpoints in real time, wherein the MCUs are clustered to achieve unlimited scaling and are built from off-the-shelf components instead of custom hardware, and wherein at least one of the media processing nodes comprises an audio transcoder, which in operation, (i) determines a sampling rate to mix audio based on the video endpoints associated with the participants in the VMR, (ii) estimates noise on each audio stream so as to determine the audio streams that are active, (iii) only voice active audio streams are mixed and equalized to reduce noise in the VMR, the mixing being performed at the determined sampling rate. a globally distributed infrastructure that supports operations of the VMR, the globally distributed infrastructure comprising a plurality of multipoint control units (MCUs) as media processing nodes, each MCU configured to process the plurality of audio and video streams from the plurality of video conference endpoints in real time, wherein the MCUs are clustered to achieve unlimited scaling and are built from off-the-shelf components instead of custom hardware, and wherein at least one of the media processing nodes comprises an audio transcoder, which in operation, (i) determines a sampling rate to mix audio based on the video endpoints associated with the participants in the VMR, (ii) estimates noise on each audio stream so as to determine the audio streams that are active, (iii) only voice active audio streams are mixed and equalized to reduce noise in the VMR, the mixing being performed at the determined sampling rate.