The terms "IP telephony" and "voice over IP" (VoIP) are synonymous. However, the term VoIP is widely used for the actual services offered (see VoIP for details), while IP telephony often refers to ...

(4) A computer system in an IP telephony network that transmits dial tones, busy signals and announcements such as "the number you have called is no longer in service." The media server can be a ...