Stream Synchronization for Voice over IP Conference Bridges

Potentially large network delay variability experienced by voice packets when travelling over IP networks complicates the design of a robust voice conference bridge. Intrastream synchronization is required at the conference bridge to smooth out network delay jitter on a given stream and provide a continuous stream of voice packets to the conference bridge core. Interstream synchronization is needed to provide time synchronization between packets in different streams, allowing for a mapping of selected voice streams to the conference bridge output and the creation of a periodic and synchronized output from the conference bridge. This work presents a design and evaluation of a Synchronized conference bridge that maps N input voice streams to M output voice streams representing selected speakers. A conference simulator, designed for this thesis, is used to characterize the performance of this bridge in terms of delay and packet loss, speaker selection accuracy and conference audio quality.