TY - JOUR N2 - The paper presents the results of research and analysis of voice data transmission quality in IP packet networks. It analyses mechanisms allowing for the assessment of packet telephony data transmission quality. Possible transmission quality levels and adequate quality metrics, applicable in the recommendations of standardisation organisations, as well as suggested limit values conditioning acceptable voice data transmission quality were indicated and discussed. A packet network model was designed and tested, taking into account VoIP architecture supporting various audio codecs used for voice compression. Transmission mechanisms based on audio codecs G.711, G.723, G.726, G.728 and G.729 were investigated. It was shown that for delay-sensitive traffic which fluctuates beyond its nominal rate, selected codecs have an advantage over others and allow for better transmission quality of VoIP traffic with guaranteed bandwidth and delay. L1 - http://www.czasopisma.pan.pl/Content/121914/PDF/102_3506_Strzeciwilk_skl.pdf L2 - http://www.czasopisma.pan.pl/Content/121914 PY - 2021 IS - No 4 EP - 750 DO - 10.24425/ijet.2021.139801 KW - MOS KW - VoIP KW - RTCP KW - QoS KW - audio codecs KW - transmission quality A1 - Strzęciwilk, Dariusz PB - Polish Academy of Sciences Committee of Electronics and Telecommunications VL - vol. 67 DA - 2021.12.27 T1 - Performance Analysis of VoIP Data over IP Networks SP - 743 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/121914 T2 - International Journal of Electronics and Telecommunications ER -