Method and apparatus for dynamically varying a packet delay in a packet network based on a log-normal delay distribution

The present invention relates to packet voice communication systems, and more particularly, to method and apparatus for enhancing the quality of service of packetized voice conversations over a Local Area Network (LAN), when the Ethernet standard is used as an access mechanism. A method and apparatus are disclosed for dynamically adapting the play-out delay for voice packets transmitted over a local area network using the Ethernet standard as an access mechanism. It has been observed that the distribution of voice packet delays in a LAN (shared by voice and data traffic) follows a log-normal distribution. An adaptive algorithm is disclosed to estimate the parameters of the log-normal distribution and to apply a dynamic play-out delay to improve the quality of packetized voice conversations, quantified by minimum delay and packet loss. For example, the size, B, of the play-out buffer can be established to ensure that the packet loss does not exceed one percent (1%). The distribution parameters are continuously updated and the size of the play-out buffer, B, is modified at the beginning of every calibration interval according to the illustrative 99% percentile of the delay distribution.