Also called Packet Delay Variation (PDV), jitter frequency is a measure of the variability in ping over time. Jitter is not usually noticeable when reading text, but when streaming and gaming a high jitter can result in buffering and other interruptions. ... Jitter testing is available with Speedtest desktop apps.
Acceptable jitter simply refers to the willingness to accept irregular fluctuations in transferring data. For best performance, the jitter must be kept below 20 milliseconds. If this exceeds 30 milliseconds, then it will cause a noticeable impact on the quality of any real-time conversation that a user may have.