A method of transmitting interleaved real-time and non-real-time data on a packet based network so as to provide voice Quality of Service comparable to the Time Division Multiplexing realm of traditional telephony. The method reduces packet jitter and delay by employing separate queues for the different types of data as well as through the use of jitter buffers. The interleaving method consists of a number of discrete concepts and mechanisms that when used together in the manner disclosed herein provides consistent high-quality transmission of real-time data over packet/frame/cell-based networks. The elements required for this method include time-slot co-ordination, a dynamic MTU algorithm, and a Multiple queue egress traffic management system.