In VoIP, measured in milliseconds, jitter is the variation in the latency on a packet flow between the sender and the receiver, when some packets take longer to travel from one system to the other.
The source of jitter can be an extreme challenge to identify (cables, hardware). Like any intermittent problem, you have a chance to find it only if you’re capturing data from the LAN at the time the problem occurs (relevant for speed test).
Jitter is basically the variance in measuring successive ping tests. Zero jitter means the results were exactly the same every time, and anything above zero is the amount by which they varied. Like the other quality measurements, a lower jitter value is better. Recommended jitter value is < 3 ms.
Jitter is significant to real-time applications because the receiver will notice Jitter as poor audio quality, audio sounds choppy.
