5.19.3.1. Connecting NI BRI Data Devices via the SLMQ3 Card 
The SLMQ3 trunk card provides the physical two-wire interface U2B1Q,
controls the connection in the D channel on the data link layer (LAPD),
and transports the Layer 3 signaling information between the NI BRI data
device and the OpenScape 4000 system. One SLMQ3 connection can support
a maximum of 8 devices. This includes analog devices that are possibly
connected behind the data devices with U or S interfaces.
OpenScape 4000 supports NI BRI devices on a SLMQ3 port as follows:
- Maximum of one data device with U interface that is directly connected with an SLMQ3 port.
- Maximum of eight data devices with S interface, which are in turn connected with one non-company-specific NT1 device that is connected to an SLMQ3 port.
- Up to seven data devices with S interface that are connected with a "passive S interface bus adapter", which in turn is connected to a non-company-specific data device that has a U interface and that is on an SLMQ3 port.
It is not possible to connect both NI BRI and DSS1 equipment to a
BRI at the same time.
