Toshiba CTX28 Telephone User Manual


 
ISDN Interfaces
RBUU/RBUS Interface Unit
7-30 Strata CTX I&M 06/04
RBUU/RBUS Wiring Guidelines
Strata CTX BRI-U interface circuits can be configured to connect to an ISDN line circuit (NT
mode, line-side) or to ISDN U-type terminal equipment TE1 or terminal adapters TA (LT
mode, station side).
Install the Toshiba-supplied Ferrite core on each ISDN circuit card per Figure 7-16 on
page 7-23. The Ferrite core is not supplied with the ISDN circuit cards must be ordered
separately.
For more information regarding the Strata CTX BRI-U interface, see “PRI and BRI Overview”
at the beginning of this chapter.
Line-side cabling
The ISDN BRI U-interface circuits are two-wire on the PSTN line-side.
The wiring from the demarc to the Strata CTX BRI circuit should be made with CAT3~CAT5
twisted pair wire.
The pinout of the Strata CTX BRI-U circuit jack is shown below.
Figure 7-26 Strata CTX BRI-U RJ45 Circuit Jack Printout
The maximum distance between the PSTN BRI interface circuit and the Strata CTX ISDN BRI
U line-side circuit (NT) is 18 kft. The Telco with the use of a repeater or fiber optic cable may
extend this distance.
The U interface pair should go directly from the demarc jack to the Strata CTX interface PCB
with no bridge taps to different locations or should not have loading coils installed.
BRI line-side cables should not be shielded.
Each line-side BRI circuit requires a ferrite core as shown in Figure 7-16 on page 7-23.
In the USA, most BRI-U Demarc jacks are RJ11, but they may be RJ45 eight-wire jacks. In
Canada the BRI-U Demarc jack is usually RJ45.
Polarity of the U interface pair is not critical.
RJ45 Jack
NT and LT Mode
4732
8
7
6
5
4
3
2
1
NC
NC
NC
Tip
Ring
NC
NC
NC
NC = No Connection
BRI Pair