Traditionally voice and data have used separate networks. Since late 90's, there has been a big effort by the telecom and datacom industries to cut their costs. With VOIP, the provider can consolidate the delivery of voice and data over a single network, e.g., the Internet, and cut the capital and operation expenses (CAPEX/OPEX) significantly. The Internet Protocol (IP) is however a connectionless technology and provides a best-effort service that result in unacceptable voice degradations compared with the legacy Public-Switched Telephone Network (PSTN). These include packet delay, jitter, and packet loss. The network devices need to implement special mechanisms to deal with these degradations. Additionally, the network devices need other protocols to provide call setup, call control, and routing to allow reliable end-to-end calls over concatenated reliable and unreliable networks and to internetwork with the legacy PSTN. In this overview, we discuss the voice characteristics and requirements, some of the mechanisms to deal with the impairments, and the protocols that are used in the next generation networks for the VOIP. In addition to the quality of service (QoS), we will briefly discuss other issues such as the US life-line, the legal telephone tapping, and emergency 911 requirements that would be easy to offer by the PSTN, but rather complex to provide by the VOIP technology.

Pizza and soda will be served for those attending!