Voice over IP (VoIP)—the use of IP for voice communications—is quickly becoming the technology that businesses are using to connect their telephone systems. One important reason for this trend is that most business phone manufacturers are freezing further development of the Time Division Multiplexing (TDM) technology that traditional phone systems use. (TDM is a method of separating a signal into many small segments at the sending end, transmitting the pieces separately, and reassembli...