Characterizing Packet Delay and Jitter Through a Semiempirical Model for VoIP Traffic

• Activity Number: 538
• Type: Contributed
• Date/Time: Wednesday, August 4, 2010 : 10:30 AM to 12:20 PM
• Sponsor: Section on Physical and Engineering Sciences
• Author(s): Jin Xia*+ and Mark Daniel Ward and William Cleveland
• Companies: Purdue University and Purdue University and Purdue University
• Keywords: VoIP ; delay ; jitter ; distribution ; semi-empirical model ; QoS

Abstract

Voice-over-IP (VoIP) quality of service (QoS) relies heavily on packet delay and jitter that result from queueing on Internet routers. Using a semi-empirical model (SEM) for VoIP traffic built in an earlier study that used measurements from a large international service provider, we study the statistical properties of delay and jitter resulting from a single queue using methods of queueing simulation. The SEM provides a high degree of validity for our results because it is an accurate reflection of the traffic properties. The results provide the first estimates, based on an empirically valided traffic model, of how much VoIP traffic can be carried on a link and satisfy QoS criteria for both delay and jitter. We also show that M/D/1 is a good approximation for the queueing delay, even at quite high utilizations. The jitter distribution is jagged but rather stable in magnitude.