Even though the terms IP telephony and VoIP are used interchangeably, they are in fact two different things. IP telephony has to do with digital telephony systems that use IP protocols for voice communication, while VoIP is actually a subset of it. VoIP is a technology used by IP telephony as means of transmitting phone calls.
VoIP systems employ session control protocols to control the set-up and tear-down of calls, as well as audio codecs which encode speech, allowing transmission of digital audio via an audio stream over an IP network. The choice of codecs varies between different implementations of VoIP, depending on application requirements and network bandwidth; some implementations rely on narrowband and compressed speech, while others support high fidelity stereo codecs. Some popular codecs include u-law and a-law versions of G.711, G.722, a popular open source voice codec iLBC, a codec that only uses 8 kbit/s each way, called G.729, and many others.
Do you need more information about this sector?
For additional information, please fill out the contact form.