When persons communicate interactively, only a minimal delay is tolerated for the communication to be considered acceptable.
Long delays are annoying and interfere with communication.
On Time Delivery . The system must provide a smooth flow of information from the transmitter to the receiver. Tolerant of Loss . Audio and video streams can tolerate the occasional loss of small amounts of information. If a particular pixel of a streaming video image is corrupted in transport, the result is not more serious than an imperceptible flash on a passing image.