Application Performance Management Blog – Shunra Software

Jitter:

Network jitter is the variation in the arrival rate of packets (more specifically, the inter packet gap of subsequent data packets as they arrive over a network). For most types of data applications large gap variations between arrival times (high jitter) are acceptable. For voice or video applications, relatively small jitter can cause perceptible disturbances in the recreated voice or video at the receiving end.
Because Wide Area Networks over IP generally rely on shared access to the network and can have many asynchronous sessions all sharing the same network they tend to introduce relatively high jitter.

Jitter can be reduced with buffers. Buffering some incoming packets and then outputting them at a more regular rate reduces jitter. This is fine for applications that are not interactive, such as streaming music or videos. For interactive applications such as VoIP conversations or video conferencing, this scheme will add network latency, which reduces the quality of the conversation.