Sarwar, Golam and Boreli, Roksana and Lochin, Emmanuel Performance of VoIP with DCCP for satellite links. (2009) In: IEEE International Conference on Communications (IEEE ICC 2009), 14-18 June 2009, Dresden, Germany .
(Document in English)
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We present experimental results for the performance of selected voice codecs using the Datagram Congestion Control Protocol (DCCP) with TCP-Friendly Rate Control (TFRC) congestion control mechanism over a satellite link. We evaluate the performance of both constant and variable data rate speech codecs (G.729, G.711 and Speex) for a number of simultaneous calls, using the ITU E-model and identify problem areas and potential for improvement. Our experiments are done on a commercial satellite service using a data stream generated by a VoIP application, configured with selected voice codecs and using the DCCP/CCID4 Linux implementation. We analyse the sources of packet losses which are a main contributor to reduced voice quality when using CCID4 and additionally analyse the effect of jitter which is one of the crucial parameters contributing to VoIP quality and has, to the best of our knowledge, not been considered previously in the published DCCP performance results. We propose modifications to the CCID4 algorithm and demonstrate how these improve the VoIP performance, without the need for additional link information other than what is already monitored by CCID4 (which is the case for Quick-Start). We also demonstrate the fairness of the proposed modifications to other flows. We identify the additional benefit of DCCP when used in VoIP admission control mechanisms and draw conclusions about the advantages and disadvantages of the proposed DCCP/ CCID4 congestion control mechanism for use with VoIP applications.
|Item Type:||Conference or Workshop Item (Paper)|
|Audience (conference):||International conference proceedings|
|Institution:||Other partners > Australian National University - ANU (AUSTRALIA)|
French research institutions > Centre National de la Recherche Scientifique - CNRS
Université de Toulouse > Institut Supérieur de l'Aéronautique et de l'Espace - ISAE
Other partners > University of New South Wales - UNSW (AUSTRALIA)
Laboratoire d'Analyse et d'Architecture des Systèmes - LAAS (Toulouse, France) - Outils Logiciels pour la Communication - OLC
Département de Mathématiques, Informatique, Automatique - DMIA (Toulouse, France) - Modelisation et Architecture des Systèmes - MARS
National ICT Australia - NICTA (AUSTRALIA)
|Deposited By:||Emmanuel Lochin|
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