> For the complete documentation index, see [llms.txt](https://isdn.learn-telecom.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://isdn.learn-telecom.com/channels/isdn-d-channel.md).

# ISDN D-Channel

The ISDN (Integrated Services Digital Network) D-Channel is a dedicated signaling channel used for establishing and managing communication sessions. 

It handles out-of-band signaling, carrying call setup and teardown messages separate from the actual voice or data transmission. 

Typically, the D-Channel operates at 16 kbps in Basic Rate Interface (BRI) configurations and 64 kbps in Primary Rate Interface (PRI) setups. 

This separation of signaling from data channels allows for more efficient communication management and dynamic allocation of network resources.