A framework for evaluating Internet telephony systems

An Internet telephony system functions like a conventional telephone to support real-time voice communication over the Internet. Numerous proprietary systems have surfaced since its introduction as a result of its main attraction of allowing transcontinental telephone calls to be made at prices of local telephone calls. Currently, these systems are at their infancy stage with no support for standards to allow interoperability among systems. A proper framework to allow evaluation or comparison between systems is also lacking. This paper proposes such a framework that utilises a feature and functionality appraisal together with both quantitative and qualitative assessment techniques to allow a systematic evaluation of Internet telephony systems to take place. These techniques include voice processor evaluation through signal reproduction, Diagnostic Rhyme Test, Diagnostic Acceptability Measure, Degradation Category Rating, and Free Conversation Test. This framework has been successfully demonstrated and utilised for the evaluation of five Internet telephony systems.