Call origination

Call origination, also known as voice origination, refers to the collecting of the calls initiated by a calling party on a

telephone exchange A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

of the

PSTN The public switched telephone network (PSTN) is the aggregate of the world's telephone networks that are operated by national, regional, or local telephony operators. It provides infrastructure and services for public telephony. The PSTN consists ...

, and handing off the calls to a

VoIP Voice over Internet Protocol (VoIP), also known as IP telephony, is a set of technologies used primarily for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as ...

endpoint or to another exchange or

telephone company A telecommunications company is a kind of electronic communications service provider, more precisely a telecommunications service provider (TSP), that provides telecommunications services such as telephony and data communications access. Many t ...

for completion to a called party. In the VoIP world, the opposite of call origination is call termination, where a call initiated as a VoIP call is terminated to the

. The term is often used in referring to a VoIP trunking service that provides the ability for calls to originate on the PSTN and be delivered to a customer's VoIP endpoint. It is often referred to as "DID" (for Direct Inward Dialing) which more properly refers to a service entirely within the PSTN where individual PSTN numbers can terminate on a customer's PBX. {{telecommunications-stub Voice over IP Teletraffic