Comparative Discussion of Circuit- vs. Packet-Switched Voice

Various other studies have already indicated potential advantage of packet-switching over tradiational circuit-switching concepts for voice communications. This paper explores the robustness of such comparisons for a range of network architectures. In particular, it is demonstrated that network sizing as related to the number of voice channels traversing a particular transmission link, and network topology with respect to the number of tandem links utilized in an end-to-end connection can have significant effects on the system performance. Estimates for end-to-end delay and the efficiency of trunk utilization are developed as a function of network topology to provide the insight necessary to identify network design limitations. A number of packet-switching design approaches, ranging from a pure datagram to a circuit-switching-like mode, are also discussed together with their effects on overall performance.