Thursday, July 1, 2010

Jitter definition - from wiki

Packets from the source will reach the destination with different delays. A packet's delay varies with its position in the queues of the routers along the path between source and destination and this position can vary unpredictably. This variation in delay is known as jitter and can seriously affect the quality of streaming audio and/or video. A network could possibly have zero jitter.
The jitter is basically the latency variation and does not depend on the latency. You can have high response times and a very low jitter. The jitter value is particularly important on network links supporting voice over IP (VoIP) because a high jitter can break a call.

Bandwidth-Delay Product (BDP)

The BDP of a path is the product of the (bottleneck) bandwidth and the delay of the path. Its dimension is "information", because bandwidth (here) expresses information per time, and delay is a time (duration). Typically, one uses bytes as a unit, and it is often useful to think of BDP as the "memory capacity" of a path, i.e. the amount of data that fits entirely into the path (between two end-systems).

BDP is an important parameter for the performance of window-based protocolsTCP. Network paths with a large bandwidth-delay product are called Long Fat Networks or "LFNs". such as