EVALUATING NMP QUALITY OF SERVICE Experiment with JackTrip regarding Latency versus Packet Jitter/Dropouts with High Quality Audio via LAN and WAN UTVÄRDERING AV QUALITY OF SERVICE VID NMP Experiment med JackTrip angående Latens kontra Jitter/Tapp av Paket med Högkvalitetsljud via LAN och WAN Bachelor Degree Project in Information Technology G2E 22,5 hp Spring term 2018 Daniel Müntzing,
[email protected] Supervisor: Dennis Modig Examiner: Jianguo Ding 1 Abstract This study has developed a method to create an, to a big extent, automated testing system for NMP (Networked Music Performance) communication over LAN and WAN to be able to benchmark the UDP streaming engine JackTrip using a client-server model. The method is not locked into using JackTrip only, it could be used to do experiments with other engines too. The study tried to answer the question if latency correlates to amount of correctly aligned audio, and to what extent the audio is correctly aligned in respect to tolerated latency (based on earlier research) when at least two musicians remote- conducting musical pieces together. There were 13 different buffer settings tested, which used no redundancy and redundancy of 2, and which were sent through 4 different LAN/WAN-scenarios. A big dataset was produced, with about 82 minutes’ worth of audio per test. To post-process the data a phase cancelling method was used to measure correctly aligned audio, while the latency was measured by counting the number of samples from the start of each audio file to the first sample that were not null or not under a certain threshold.