Efficiency of packet voice with deterministic delay

Packet switching is appealing for carrying real-time traffic because it can benefit from (possibly variable bit rate) compression schemes and statisti cal multiplexing to more efficiently exploit network resources. This work e xplores the efficiency of IP telephony in terms of the volume of voice traf fic carried with deterministically guaranteed quality related to the amount of network resources used. An IP network carrying compressed voice is comp ared to circuit switching carrying PCM (64 kb/s) encoded voice, and some de sign choices affecting IP telephony efficiency are discussed.