What is the 16 Kbps line used for in ISDN connection?

In an ISDN (Integrated Services Digital Network) connection, the 16 Kbps line refers to a B-channel that is used for data transmission. ISDN typically provides two B-channels (each 64 Kbps) and one D-channel for signaling and control. The 16 Kbps line can be utilized for specific low-bandwidth applications, such as voice or data services, allowing multiple channels to be combined for more efficient use of the available bandwidth. This makes it suitable for basic telephony and simple data communications.