Measuring the quality of service of voice over IP

Abstract

This thesis addresses and proposes the methods to measure and classify problems encountered when transmitting voice over the Internet. These problems are delay, jittering, and lost of data. Transmitting voice over the Internet is commonly known as Voice over Internet Protocol (VoIP). The fact that the current Internet infrastructure was not designed to transmit real-time data makes these problems become eminent. Solutions to improve the quality of real-time data transmissions over the Internet are currently under research. This thesis presents a VoIP software-based application tool to help VoIP engineers to better measure and classify these problems. This software tool is called Voice Over Internet Protocol Quality of Service Measuring Tool (VoIP QoS MT). This tool works in a live mode and in a test traffic mode. Live mode allows users to transmit actual voice conversations between two computers over the Internet, using a few digitization and compression schemes. Quality of service can be observed in real-time speech. The test traffic mode works without voice conversation. Its payloads are programmed to carry information for the purpose of testing delay, jittering, and lost statistics. Detailed functionalities and related background information for each components used in the application are presented accordingly in this paper