What Is ISDN?
ISDN stands for Integrated Services Digital Network and it is a digital network providing 64 Kbit and 2 Mbit bandwidth voice and data circuits. A set of international standards for telephone transmission.
ISDN provides an end-to-end digital network, out-of-band signalling, and greater bandwidth than older telephone services.
The two standard levels of ISDN are Basic Rate Interface (BRI) and Primary Rate Interface (PRI). See Basic Rate Interface and Primary Rate Interface.
Author: Robyn Coppell
Reviewed by: Megan Jones
Published On: 2nd Mar 2023 - Last modified: 25th Sep 2025
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