An Internet telephony service provider (ITSP) offers digital

telecommunications service In telecommunication, a telecommunications service is a service provided by a Telecommunications company, telecommunications provider, or a specified set of User (telecommunications), user-information transfer capabilities provided to a group of use ...

s based on

Voice over Internet Protocol Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet ...

(VoIP) that are provisioned via the

Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a ''internetworking, network of networks'' that consists ...

. ITSPs provide services to end-users directly or as whole-sale suppliers to other ITSPs. ITSPs use a variety of signaling and multimedia protocols, including the

Session Initiation Protocol The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications. SIP is used in Internet telephony, in private IP telep ...

(SIP), the

Media Gateway Control Protocol The Media Gateway Control Protocol (MGCP) is a signaling and call control communication protocol used in voice over IP (VoIP) telecommunication systems. It implements the media gateway control protocol architecture for controlling media gatew ...

(MGCP),

Megaco The Gateway Control Protocol (Megaco, H.248) is an implementation of the media gateway control protocol architecture for providing telecommunication services across a converged internetwork consisting of the traditional public switched telephone n ...

, and the

H.323 H.323 is a recommendation from the ITU Telecommunication Standardization Sector (ITU-T) that defines the protocols to provide audio-visual communication sessions on any packet network. The H.323 standard addresses call signaling and control, m ...

protocol.

is one of the earliest VoIP protocols, but its use is declining and it is rarely used for consumer products. Retail customers of an ITSP may use traditional analog telephone sets attached to an analog telephony adapter (ATA) to connect to the service provider's network via a

local area network A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building. By contrast, a wide area network (WAN) not only covers a larger ...

, they may use an IP phone, or they may connect a private branch exchange (PBX) system to the service via media gateways. ITSPs are also known as voice service providers (VSP).

History

In the United States, net2Phone began offering consumer

VoIP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Interne ...

service in 1995. Usually, ITSPs negotiate agreements for route termination to various parts of the world from multiple VoIP providers. ITSP customers may be able to choose a VoIP provider for their VoIP calls. Customers may be able to do this by specifying the maximum price they are willing to pay per minute for a call and the lowest quality they are willing to tolerate. The ITSP routing software searches for the wholesale VoIP providers who meet the customer specification and attempt to route the customer call to the providers starting with the one have the lowest quoted price. Pricing to different parts of the world depend on several factors, such as the routing via a white route or a black route, wholesaler's margin, and the country's regulations.

References

{{Telecommunications Voice over IP

History

See also

References