OpenScape 4000 supports the connection of NI BRI data devices both via the ISDN terminal adapter (known as TA S0) in an optiPoint telephone and via the USB port of an optiPoint telephone.

The TA S0 is the NT1 reference point; the connected NI BRI data devices can access the B and D channels of an SLMO port via the TA S0. Included in the NI BRI data devices supported over this interface are Group 4 fax devices and data station devices. These have their own power supplies.

The TA S0 module performs the Layer 1 interworking between the NI BRI data device with S interface and the UP0/E transmission code to the SLMO card. The Layer 2 and 3 signaling information is transparently transported between the NI BRI data device and the OpenScape 4000 system.

The TA S0 is supported in optiPoint telephones. With the optiPoint telephones, OpenScape 4000 also supports a 2B + D interface, which is provided via the ISDN application on a PC that is connected to the optiPoint telephone USB port.