Instruction manual

Universal Slot PCBs
CO Line PCBs
44 Strata DK General Description 6/00
A maximum of two simultaneous voice and/or data calls are allowed between all devices
connected to the same BRI circuit. The contention rule for the two BRI B channels is first come,
first serve. Network connections using BRI S/T type interface also require a dealer-supplied,
UL-listed, external Network Terminal (NT-1) device. In Canada, the NT-1 must be CSA certified.
Basic Rate Interface Subassembly (RBSS)
The RBSS attaches to the RBSU to provide two additional BRI S/T type circuits that can be used
for station-side connections only. An RBSU with the RBSS subassembly provides four BRI
circuits in one card slot.
RBSU/RBSS stations can be voice and/or data devices, such as ISDN telephones and Terminal
Adapters, that support the standard S-type interface. Each RBSU/RBSS circuit provides two B
channels, plus one D channel and reduces the system’s basic capacity by two station ports and two
CO lines. See “ISDN Basic Rate Interface (BRI)” on Page 79 for more information.
ISDN U-type Basic Rate Interface Unit (RBUU)
The Basic Rate Interface Unit provides two Basic Rate Interface (BRI) “U” circuits. Each circuit
provides two simultaneous voice and/or data connections with a single interface. BRI uses the
2B+D transmission format which is defined as two 64-kbps bearer channels and one 16-kbps data
(control) channel.
Basic Rate Interface Subassembly (RBUS)
The RBUS attaches to the RBUU to provide two additional BRI “U” circuits that can be used to
connect to Network BRI lines and/or station-side connections only. An RBUU with the RBUS
subassembly provides four BRI “U” circuits in one card slot.
RBUU/RBUS stations can be voice and/or data devices, such as ISDN telephones and Terminal
Adapters, that support the standard U-type interface. Each RBUU/RBUS circuit provides two
B channels plus one D channel and reduces the basic system capacity by two CO lines and two
station ports. See “ISDN Basic Rate Interface (BRI)” on Page 79 for more information.
Enhanced 911 CAMA Trunk Interface Unit (RMCU/RCMS)
The RMCU/RCMS PCBs provide up to four CAMA trunk circuits. The RMCU/RCMS eliminates
the need for connection of adjunct terminal adapter equipment to E911 CAMA trunks. Also, see
note below RCMS.
CAMA Trunk Subassembly (RCMS)
One RCMS subassembly attaches to the RMCU to provide two CAMA trunk circuits. A second
RCMS can be added to provide four CAMA trunk circuits.
Note The RCMS is ordered separately from the RMCU, but it must be installed on the RMCU
to provide CAMA trunk interface.