Toshiba Strara CTX Series, Руководство по установке и обслуживанию

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ISDN Interfaces
5-9
Strata CTX I&M September 2002
RBSU/RBSS Interface Units
Circuits per PCB:
2 circuits (2B + D each circuit)
Interfaces with:
ISDN BRI TE when connected to the Public Network or a BRI S-type, NT or TA devices
when connecting to ISDN station equipment
Older Version(s):
none
RBSU/RBSS switches, jumpers, and connectors are shown in Figures 5-9 and 5-10 on page 5-12 and
described in Table 5-3 .
LEDs on the RBSU/RBSS show a continuous status of BRI operation. Refer to Table 5-4 on Page 5-14
for a list of each LED’s status.
Overview
The RBSU and RBSS PCBs provide the Basic Rate Interface (BRI) circuits. The RBSU is the main
plug-in PCB that plugs into the Strata CTX cabinet slots.
The RBSS is an optional PCB that plugs onto the RBSU. Each PCB provides two ISDN BRI circuits.
Each BRI circuit provides 2 B-ch 1D channel for voice/data/video applications.
An REBU PCB is a piggy-back PCB that plugs onto the RBSU and provides basic functions for
RBSU/RBSS circuits so it must always be installed on the RBSU.
The RBSU circuits are four-wire S/T type circuits and connect to the Public Switched Telephone
Network (PSTN) BRI lines using an Network Terminator unit (NT1); or, on the station side, they can
connect to ISDN Terminal Equipment (TE) or Terminal Adapters (TA) as shown in
Figure 5-7 .
TE devices include any ISDN device (telephone, fax, computer) that connects directly to S/T ISDN
BRI circuits. TA devices match the protocol of non-ISDN devices (telephone, fax, computer) to the
protocol of S/T ISDN BRI circuits.
RBSU circuits can be configured as:
◆
BRI – TE circuits which connect to Telephone Network BRI lines using a NT1.
◆
BRI – NT circuits which connect to ISDN TEs or TAs. These devices must be S-type station
devices.
Important! The Strata CTX BRI circuits allocate line numbers and station ports differently. Each BRI
circuit consumes two line numbers and two station port when configured as line-side or
station side.
The RBSU connection options (BRI line or ISDN TE-1/TA devices) are selected in customer database
programming and option switches located on the RBSU.
The network BRI line connection is a point-to-point connection, which means that the network BRI
line can only be connected to one RBSU circuit via the NT1 (T-reference point).
RBSS circuits connect directly to S-type TE-1 or TA ISDN devices only. They do not support BRI-TE
telephone network BRI line connections.
The RBSU, and/or RBSS circuits that connect to the Strata CTX station side, (BRI-NT, S-reference
point) allows direct connection of multiple ISDN (TE-1 or TA) devices. The S point of the RBSU/
RBSS supports the Toshiba Strata CTX passive bus, also known as point-to-multipoint connection.
The terminal-side (S-point) of the RBSU/RBSS BRI circuit can have parallel connections of up to two
TE-1s or TAs maximum.