ISDN Applications

Current telecommunication services are often provided by separate networks -- voice, circuit-data, packet-data, telex, private-line networks, etc. Each network may require a dedicated physical access and a separate signaling and addressing scheme. In the last ten years, there has been a recognition of the need for a more integrated approach. From a user's viewpoint, there could be one virtual network providing all services via an access interface whose characteristics are service independent. This recognition has led to a worldwide vision called the Integrated Services Digital Network (ISDN).