A system and method for reducing end-to-end delay associated with telephone calls carried over a voice over packet network in a manner that avoids overloading of the network. The system and method involves monitoring one or more parameters indicative of an amount of bandwidth being utilized on the voice over packet network, responsive to the monitoring, determining that a level of bandwidth utilization on the voice over packet network has changed, responsive to the determination that the level of bandwidth utilization on the voice over packet network has changed, issuing a command to a telephony device, and responsive to receipt of the command by the telephony device, changing the size of packets used for carrying frames of encoded voice signals associated with a telephone call from a first packet size to a second packet size.