An Internet telephony service provider (ITSP) offers digital

telecommunications service In telecommunication, a telecommunications service is a service provided by a telecommunications provider, or a specified set of user-information transfer capabilities provided to a group of users by a telecommunications system. The telecommunicati ...

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 t ...

(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 '' network of networks'' that consists of private, pub ...

. 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 telepho ...

(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 gatewa ...

(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 An analog telephone adapter (ATA) is a device for connecting traditional analog telephones, fax machines, and similar customer-premises devices to a digital telephone system or a voice over IP telephony network. An ATA is often built into a sma ...

(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 Net2phone provides VoIP and cloud computing-based telephony products and services. The company is a subsidiary of IDT Corporation. History Net2Phone was founded in 1990. On July 30, 1999, during the dot-com bubble, the company became a public com ...

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 Internet t ...

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 In telecommunications business, a white route is a route where both source and destination are legal termination. This is opposed to a black route, which is a route that is illegal in both ends. Also common in telecom (especially VoIP) is the ter ...

or a black route, wholesaler's margin, and the country's regulations.

References

{{Telecommunications Voice over IP

History

See also

References