he mathematical and sim- ulation results including buffer size, mean queuing delay and standard devi- ation of queuing delay for error probability of a SIP-T message, Pe = 0.004. Mean queuing delay and standard deviation of queuing delay vary slowly as a function of the queue size for SIP-T messages arrival rate of less that 450. However, these values increase dramatically when the arrival rate of SIP-T messages exceeds 450. This phenomenon is due to the SIP-T message arrival rate approaching the processing capability of the system for heavy traffic intensity [2]. It can be observed that the theoretical estimates are in excellent agreement with simulation results. Therefore we can determine the cost to per- formance planning and design compromises needed to meet the requirements of a carrier class VoIP network. 22.2.2.1.1 Call setup delay Call setup delay consists of the post-dialing delay, answer-signal delay and call-release delay. The post dialing delay occurs when signaling takes place through the network to the receiver. These delays happen during the lifetime of a SIP call. A measure of these delays was TABLE 22.1 Mathematical Results SIP-T message Standard queue size (messages/s) Mean (ms) deviation (ms) Buffer size 25.00 18.57 Source: Wu, J.S., and P.Y. Wang. 2003. The performance analysis of SIP-T signaling system in carrier class VoIP network. 17th International Conference on Advanced Information Networking and Applications (AINA'03), IEEE. 39. March. © 2009 by Taylor & Francis Group, LLC SIP Handbook: Services, Technologies, and Security TABLE 22.2 Simulation Results SIP-T message queue size Mean and Standard Buffer Sample size (messages/s) 95th percent (ms) deviation (ms) (SIP-T message) 0.49 + 0.01 100.7 0.61 + 0.01 10074 150.4 0.79 + 0.01 15044 201.8 0.98 + 0.02 20178 251.4 1.27 + 0.02 25138 301.1 1.70 + 0.02 30115 348.9 2.36 + 0.03 34891 399.5 3.62 + 0.04 39955 450.7 6.49 + 0.06 45067 502.5 21.08 + 0.18 20.12 50251 Source: Wu, J.S., and P.Y. Wang. 2003. The performance analysis of SIP-T signaling s