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Analysis of on-off patterns in VoIP and their effect on voice traffic aggregation Wenyu Jiang, Henning Schulzrinne Department of Computer Science Columbia University Computer Communications and Networks, 2000. Proceedings. Ninth International Conference on.
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Analysis of on-off patterns in VoIP and their effect on voice traffic aggregationWenyu Jiang, Henning SchulzrinneDepartment of Computer Science Columbia UniversityComputer Communications and Networks, 2000. Proceedings. Ninth International Conference on Estimation of Token Bucket Parameters of VoIP TrafficR. Bruno, R.G.Garroppo and S.GiordanoDepartment of Information Engineering University of Pisa High Performance Switching and routing, 2000. ATM 2000 Proceedings of the IEEE Conference on , 2000
Outline • Introduction • Experiment Setup • Comparisons with Traditional Silence Detectors • Token bucket simulations and results • Conclusions
Introduction • Human speech consists of talk-spurts and silence gaps, also known as on-off patterns. • Allows higher bandwidth utilization through multiplexing. • Allows per-spurt play out delay adjustment. • Enable echo suppression based on silence detector output.
Introduction (cont’d) energy Max (-20db) Min (-45db) time Pre-spurt hangover time Post-spurt hangover time
Experiment Setup Mediatrix gateway 3COM Ethernet Phone 3COM Ethernet Phone
Comparisons with Traditional Silence Detectors • Example spurt/gap distributions • NeVoT SD spurt and gap CDF using different parameters • Spurt/gap distribution after averaging over many conversations
Spurt/gap distribution after averaging over many conversations
Spurt/gap distribution after averaging over many conversations
Spurt/gap distribution after averaging over many conversations
Effect of spurt/gap distribution on multiplexing performance, G.729B
Effect of spurt/gap distribution on multiplexing performance, G.729B
Effect of spurt/gap distribution on multiplexing performance, G.729B
Multiplexing performance for NeVoT SD with default parameters
Multiplexing performance for NeVoT SD with default parameters
Multiplexing performance for NeVoT SD with default parameters
Simulation analysis Multiplexer token-bucket conditioner classifier
Conclusions • Spurt/gap distributions are not exactly exponential, particularly for gaps. • The token bucket simulations result indicate that the exponential model generally gives a close estimate of the out-of-profile probability.