It is the business practice of sending all clients' billing info to a separate company, who then does everything for you. It also allows a company to cut down on time and human resources spent on administrative tasks.
A Media Gateway Control Protocol (MGCP) is a Voice over Internet Protocol system used to handle the exchange of information and the management of a multimedia conference session. The exchange of information, known as signaling, is responsible for connecting, controlling and terminating sessions. Therefore, an MGCP protocol is used to set up, maintain and end calls between multiple points.