According to Michiel Van Kets, Integrated Services Digital Network is designed to allow digital voice and data transmission over copper telephone wires. It provides improved voice quality and both circuit-switched and packet-switched technologies for voice and data. Although it is still available in the United States and Europe through telephone companies, cable modems and even wireless broadband provide better throughput speeds and are more popular as of 2014.
Integrated Services Digital Network is able to provide throughput speeds of 128 Kbps. It doubled the speed of 56K telephone modems and is a more affordable alternative to other types of Internet access as of 2014. According to SearchEnterpriseWAN, service includes B-channels, or bearer channels, to carry data, voice and other services, and D-channels, which are signaling channels, to carry control and signaling information. Integrated Services Digital Network offers two levels of service: Basic Rate Interface for use in homes and small businesses with two 64 kbps B-channels and one 16 kbps D-channel providing up to 128 kbps; and Primary Rate Interface for heavy commercial and educational uses built on 23 B-channels and one 64 Kpbs D-channel in the United States and 30 64 kbps B-channels and one 64 kbps D-channel in Europe. In telephony, Integrated Services Digital Network is a smart-network technology that can add new services to the public switched telephone network, while it is used in the broadcast industry for switching high-quality, low-latency audio circuits.