Testing of the effect of load on voice quality in VoIP networks

摘要

A new trend in the communication world is called convergence of telephony and data network on IP based principles. An implementation of a new type of network brings a lot of advantages, especially cost savings for both providers and network users. New principles of work of a new type of network offer to users unrestricted access to different service providers and support generalized mobility which will allow consistent and ubiquitous provision of services to users. At the same time, a modernization process brings a number of technical problems to be solved. One of the main challenges seems to be quality of speech signal in VoIP transmission channel. The assessment of the call quality for the above mentioned networks requires using new approaches. Nowadays, there are many standardized subjective and objective sophisticated methods of speech quality evaluations. We can find a series of software tools working in accordance with the required recommendations and laws of statistics that are designed to assess the current state of ongoing VoIP communication. We chose Alcatel VoIP Assessment Tool 3.0 and widely known CommView SW. We tested the parameters and their combinations that influence the quality of the transmitted voice most. Presented results are obtained from the measurement done on systems which perform in real networks of the Armed Forces of the Czech Republic (the ACR).