ISDN Interfaces
RBSU/RBSS Interface Units
5-12
Strata CTX I&M 10/02
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.
When multiple TE-1 and TA devices are installed on a single RBSU/RBSS BRI circuit, the devices
must share, or contend for, that circuit’s two B-channels. That is to say, a maximum of two
simultaneous voice and/or data calls are allowed between both devices connected to the same BRI
circuit. The contention rule for the two BRI B-channels is first come, first serve.
Figure 5-7
RBSU/RBSS Interfaces between the S/T Reference Points
Capacity and Cabinet Slot Information
The RBSU/RBSS can be installed in any slot except in a slot that has been left vacant to provide
capacity for RDTU, RPTU2 or RPTU as shown in
Tables 1-54
and
1-55
. Each RBSU and/or RBSS
contains two circuits and each circuit reduces the system capacity by two station ports and two CO
lines (one port/line per B-channel). Therefore, if the RBSU PCB is installed, the station port and
CO line count will increment by four ports and four lines at the RBSU cabinet slot.
If the RBSU/RBSS is installed, the station port and CO line count will increment by eight station
ports and eight lines at the RBSU/RBSS cabinet slot. RBSU and RBSS PCBs can be installed in
any combination so long as the number of RBSU PCBs is the same or greater than the number of
RBSS PCBs. See
“ISDN BRI Digital Station PCBs” on page 1-39
and
“Worksheet 3: CO Line” on
page 1-25
for the maximum BRI circuits allowed.
PS-1 Backup Power Option
The RBSU provides an optional backup power supply, R40S, that will supply backup power to TE
devices in the event of an AC power loss. This power backup option only applies to RBSU or
RBSS circuits that are configured in the NT mode. See
Figure 5-11
to install the R40S.
Also the Strata CTX system must have battery backup to allow the R40S power backup function to
operate. The R40S power supply is an ISDN, PS-1 type power unit which means it supplies power
to TE devices on the RBSU/RBSS transmit and receive wire pairs as shown in
Figure 5-8
. This
power arrangement is also known as phantom power.
Each of the four circuits on RBSU/RBSS can be connected to share the R40S using option
switches on the PCBs (see
Table 5-4
). Before using the R40S as a backup power source, make sure
the TE devices do not require more power than the R40S can supply and the TE is compatible with
the ISDN PS-1 power arrangement.
RX
TX
DK TBSU or
RBSU/RBSS
NT1
RX
TX
PSTN
RX/TX
U
T
S
BRI
(2-wire)
BRI-TE
(4-wire)
BRI-NT
(4-wire)
3336
S, T, and U are ISDN reference points.
TE = S-type Terminal Equipment
TA = S-type Terminal Adaptor
TE-1
or
TA
2
. .
.
TE-1
or
TA
Содержание Strata CTX100
Страница 16: ...Introduction Related Documents Media xii Strata CTX I M 10 02 ...
Страница 94: ...Strata CTX100 Installation Installing the CTX100 Cabinet 2 24 Strata CTX I M 10 02 ...
Страница 150: ...Strata CTX670 Installation Remote Expansion Cabinet Unit 3 56 Strata CTX I M 10 02 ...
Страница 188: ...PCB Installation Network Requirements 4 38 Strata CTX I M 10 02 ...
Страница 238: ...T1 Loop Back Testing 6 12 Strata CTX I M 10 02 ...
Страница 310: ...Station Apparatus 2000 series Telephones 8 48 Strata CTX I M 10 02 ...
Страница 342: ...Peripheral Installation Station Message Detail Recording SMDR 9 32 Strata CTX I M 10 02 ...