Holding, Conversation and Setup Times Probability Distributions of Bulk Internet Telephony Traffic for VoIP/PSTN Gateways

摘要

Earlier analysis of PSTN and GSM data has shown that the logarithmic measurement scale and mixtures of random variables are two properties of the circuit holding time as a random variable. We investigate the validity of this concept on bulk international Internet telephony traffic to VoIP/PSTN gateways. Our approach is based on call progress signaling messages where we perform a comprehensive study on different critical stages of a call and derive a traffic characteristics analysis. Inter-arrival distributions have shown to remain exponential while total holding times suggest similar logarithmic characteristics. On the contrary, we show that conversation times are best described by the beta distribution. Therefore, we decline the previously proposed logarithmic human perception of time as the sole reason for changes in the traffic behavior over the past century. We suggest that the large increase in short unsuccessful calls, is the main contributing factor for the changes in the traffic characteristics.