bfb86586_Test___Test_Your_ISP_Bandwidth__Why_It_Matters
[What's Measured] Jitter [What Is It?] The variation over time of the latency across a network. [How It's Measured] Measured in ms (milliseconds) as the average variation of time of total data packets attempted. [Why It Matters] 
High jitter values may cause voice packets to be delivered out of order, which can result in echo or talk-over effects.
MegaPath Bandwidth Test | Test Your ISP Bandwidth
Why It Matters