ystem in carrier class VoIP network. 17th International Conference on Advanced Information Networking and Applications (AINA'03), IEEE. 39. March. undertaken by Cursio and Landan [5] using a 3G network emulator. The results account for local, national, international and overseas Intranet LAN calls. Post-dialing delay (PDD) is also called post-selection delay or dial-to- ring delay. This is the time between when the caller clicks the button of the terminal to call another caller and the time the caller hears the callee terminal ringing. Answer-signal delay (ASD) is the time between when the callee picks-up the phone and the time the caller receives indication of this. This delay obviously a function of the depth and extent of the network infrastructure between the caller and callee. In a local call scenario, this time is relatively short. For international and long distance calls is can be significant. Call-release delay (CRD) is the time elapsed between when the releas- ing party (the caller) hangs-up the phone and the time the same party can initiate/receive a new call. Table 22.3 is a summary of these delays: TABLE 22.3 3G SIP Calls VS. Intranet Calls Delay Results 24 ms 38 ms 153 ms 24 ms 62 ms 23 ms 31 ms 147 ms 237 ms 45 ms 11 ms 30 ms 138 ms 230 ms 50 ms Source: Curcio, I.D.D., and M. Lundan. 2002. SIP call setup delay in 3G networks. Seventh International Symposium on Computers and Communications (ISCC'02), 835. © 2009 by Taylor & Francis Group, LLC SIP Security and Quality of Service Performance The values in Table 22.3 are relative to the point of call and the desti- nation and therefore are subject to wide variations. For example, a SIP call between Europe and Australia will result to significantly larger PDD, ASD and CRD. Tests in the case of bandwidth limitations were also carried out by Curcio and Lundan [5]. The call success rate was always 100%, therefore band- width limitation does not prevent a successful SIP call. The PDD for 2 kbps bandwidth was less that 1 sec. This is significantly large comp