Abstract: A token ring local area network includes workstations running both conventional data and multimedia applications. The latter, which generally requires a minimum throughput in order to be viable, can be split into two further categories; those which cannot tolerate excessive latency (end to end delay), typically interactive applications such as voice communications, and those which are less sensitive to latenoy, typically playback operations, the network recognises three priority levels: (1) for latency-sensitive multimedia applications, (2) for latency-insensitive multimedia applications, and (3) conventional applications. All multimedia applications prior to commencement of any communications over the LAN must request an allocation of throughput from a LAN segment resource manager (LSRM), which will only be awarded if there is currently sufficient available throughput on the LAN to support the attended communication.

Abstract: A computer workstation receives multiple audio input streams over a network in an audio conference. The audio input streams are kept separate by storing them in different queues. Digital samples from each of the queues are transferred to an audio adapter card 28 for output. A digital signal processor 46 on the audio adapter card multiplies each audio stream by its own weighting parameter, before summing the audio streams together for output. Thus the relative volume of each of the audio output streams can be controlled. For each block of audio data, the volume is calculated and displayed to the user, allowing the user to see the volume in each audio input stream independently. The user is also provided with volume control for each audio input stream, which effectively adjusts the weighting parameter, thereby allowing the user to alter the relative volumes of each speaker in the conference.