Improving VoIP quality through path switching

Shu Tao, Kuai Xu, Antonio Estepa, Teng Fei, Lixin Gao, Roch Guérin, Jim Kurose, Don Towsley, Zhi Li Zhang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

84 Scopus citations


The current best-effort Internet cannot readily provide the service guarantees that VoIP applications often require. Path switching can potentially address this problem without requiring new network mechanisms, simply by leveraging the robustness to performance variations available from connectivity options such as multi-homing and overlays. In this paper, we evaluate the effectiveness and benefits of path switching in improving the quality of VoIP applications, and demonstrate its feasibility through the design and implementation of a prototype gateway. We argue for an application-driven path switching system that accounts for both network path characteristics and application-specific factors (e.g., codec algorithms, playout buffering schemes). We also develop an application path quality estimator based on the ITU-T E-model for voice quality assessment, and an application-driven path switching algorithm that dynamically adapts the time scales over which path switching decisions are made to maximize voice quality. Through network emulation and experiments over a wide-area multi-homed testbed, we show that, with sufficient path diversity, path switching can yield meaningful improvements in voice quality. Hence by exploiting the inherent path diversity of the Internet, application-driven path switching is a viable option in providing quality-of-service to applications.

Original languageEnglish (US)
Title of host publicationProceedings - IEEE INFOCOM 2005. The Conference on Computer Communications - 24th Annual Joint Conference of the IEEE Computer and Communications Societies
EditorsK. Makki, E. Knightly
Number of pages11
StatePublished - 2005
Externally publishedYes
EventIEEE INFOCOM 2005 - Miami, FL, United States
Duration: Mar 13 2005Mar 17 2005

Publication series

NameProceedings - IEEE INFOCOM
ISSN (Print)0743-166X


Country/TerritoryUnited States
CityMiami, FL

ASJC Scopus subject areas

  • General Computer Science
  • Electrical and Electronic Engineering


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