The ISDN call recording for Bri channel recording is a call recording device for connection to ISDN So basic rate interfaces. The ISDN busses are passively tapped with a high impedance circuit.

The digital contents of the ISDN frames are transferred to the PC via a USB cable, which is also used to power the device. Software on the PC decodes the information in the D channel and creates audio files from the B channel data during active calls. All data is stored on the hard disk of the PC operating the device.

The ISDN has 16 multi-colour status LEDs. These indicate:

  • device activity,
  • ISDN line power feeding state,
  • layer 1 and layer 2 activity,
  • signal polarity and
  • B-channel usage (calls in progress).

The device and software can automatically detect if an S0 bus is operated in point-to-point or in point-to-multipoint configuration.