Ahstract-VoIP implementations are nowadays the preferred information technology alternative to public switched telephone networks. With dependence on this technology, VoIP quality and performance are critical. In this paper, we implement some commonly used VoIP CODECs on Windows desktop operating systems to evaluate their performance on two versions on IP, namely IPv4 and IPv6. Performance related metrics like throughput, jitter and latency are empirically measured in all combinations of operating systems with various CODECs and IP versions. A test-bed setup is employed to measure performance related metrics. Results obtained show that there is only a slight difference in performance between TCP IPv4 and IPv6 networks, however VoIP throughput, jitter and latency values are significantly different depending on the choice of CODEC, operating system and the IP version. Windows operating system, CODEC, operating systems I. I NTRODUCTION Information Technology continue to rigorously enhance all aspects of personal, business and social activities in the twenty-first century living. Times are changing, technology is changing, and so do the demands and the expectations of millions of global users. Undoubtedly, the Internet is playing a vital role by providing a global information superhighway unrivalled by any other technological advancement. Internet Protocol (IP) version 4 currently forms the Internet cloud and has numerous limitations -this eventually will be replaced with version 6. The new version addresses inherent problems in the earlier version, and it offers new opportunities that can enhance communication experiences of users beyond current scope. However, IPv6 has larger data overhead than its counterpart, which hints network performance issues. In this paper, we performance analyze two commonly used Windows desktop operating systems, implemented with different versions of Internet Protocol, for three different voice CODEC types. The empirical experiments are conducted on a test-bed, and performance related metrics like throughput, delay, latency and jitter are measured. Our 978-1-4244-5540-9/10/$26.00 ©2010 IEEE 669 results show voice CODEC types give different performance metrics values depending on operating system and IP version.The rest of the paper is organized as follows: Section II describes Voice over IP CODECs, similar work undertaken by other researchers is mentioned in Section III, and Section IV outlines the experimental setup used in this research. We present the results and discuss the findings in Section V.Finally, the research is concluded in Section VI.
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B ACKGROUNDVoIP, also commonly known by descriptors such as IP telephony and broadband phone uses TCPIIP networks to establish voice communication between devices. Since voice is analogue and the TCP/IP media is digital, CODEC is used to compress analog voice signal to digitally encoded version that can travel on computer networks. Sound quality, bandwidth required, and resource requirements all depends on the choice of CODEC. G.7xx, inclu...