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 protocols such as TCP. Network paths with a large bandwidth-delay product are called Long Fat Networks or "LFNs".

References

• What is the Bandwidth * Delay Product?, speedguide.net Tweaking FAQ, http://www.speedguide.net/faq_in_q.php?category=89&qid=185

– Main.SimonLeinen - 14 Apr 2005