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By Andrew Garcia  |  Posted 2005-05-30 Print this article Print

Good call, bad call The MOS and the R-Value score are the most common scoring methods for voice quality. The compression characteristics of voice codecs limit possible scores for VOIP networks, so the highest grades are never actually achievable.
  • MOS Subjective voice assessment score traditionally based on user-perception reports, with a score of 1 meaning unusable and 5 meaning excellent.
  • R-Value Part of the ITU (International Telecommunication Union) G.107 specification to measure call quality. On a 1-to-100 scale, R-Value is an objective measurement technique that accounts for loudness and various signal impairments— and even includes a fudge factor to weigh for user expectations. Technical Analyst Andrew Garcia can be reached at

    Check out eWEEK.coms for the latest news, views and analysis on voice over IP and telephony.

    Andrew cut his teeth as a systems administrator at the University of California, learning the ins and outs of server migration, Windows desktop management, Unix and Novell administration. After a tour of duty as a team leader for PC Magazine's Labs, Andrew turned to system integration - providing network, server, and desktop consulting services for small businesses throughout the Bay Area. With eWEEK Labs since 2003, Andrew concentrates on wireless networking technologies while moonlighting with Microsoft Windows, mobile devices and management, and unified communications. He produces product reviews, technology analysis and opinion pieces for, eWEEK magazine, and the Labs' Release Notes blog. Follow Andrew on Twitter at andrewrgarcia, or reach him by email at

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