Voice over Internet Protocol, also called VoIP, IP
Telephony, Internet telephony, Broadband telephony, Broadband Phone and Voice
over Broadband is the routing of voice conversations over the Internet or
through any other IP-based network.
Companies providing VoIP service are commonly referred to as providers, and
protocols which are used to carry voice signals over the IP network are commonly
referred to as Voice over IP or VoIP protocols. They may be viewed as commercial
realizations of the experimental Network Voice Protocol (1973) invented for the
ARPANET providers. Some cost savings are due to utilizing a single network - see
attached image[1] - to carry voice and data, especially where users have
existing underutilized network capacity that can carry VoIP at no additional
cost. VoIP to VoIP phone calls are sometimes free, while VoIP to PSTN may have a
cost that's borne by the VoIP user.
There are two types of PSTN to VoIP services: DID (Direct Inward Dialing) and
access numbers. DID will connect the caller directly to the VoIP user while
access numbers require the caller to input the extension number of the VoIP
user. Access numbers are usually charged as a local call to the caller and free
to the VoIP user while DID usually has a monthly fee.[2] There are also DIDs
that are free to the VoIP user but chargeable to the caller.
|