Voice over IP (VoIP) - term used in IP telephony for a set of facilities for managing the delivery of voice information using the Internet Protocol (IP).
IP telephony (Internet Protocol telephony) - general term for the technologies that use the Internet Protocol's packet-switched connections to exchange voice, fax, and other forms of information that have traditionally been carried over the dedicated circuit-switched connections of the public switched telephone network (PSTN).
latency - an expression of how much time it takes for a packet of data to get from one designated point to another.
public switched telephone network (PSTN) - the world's collection of interconnected voice-oriented public telephone networks, both commercial and government-owned. Also referred to as the Plain Old Telephone Service (POTS).
jitter - variations in packet arrival time.
Differentiated Services - protocol for specifying and controlling network traffic by class so that certain types of traffic get precedence - for example, voice traffic, which requires a relatively uninterrupted flow of data, might get precedence over other kinds of traffic. Also known as DiffServ or DS.
dynamic jitter buffer - shared data area where voice packets can be collected, stored, and sent to the voice processor in evenly spaced intervals.