Toshiba CTX28 manual Strata CTX Isdn Reference Model

ISDN Interfaces

BRI U Overview

A subassembly (RBUS) can be attached to the RBUU for two additional BRIs for PSTN and/or U-type station connections. The RBUU PCB and the RBUS subassemblies are shown in Figures 7-23and Figure 7-24 on page 7-28. The combination of RBUU and RBUS uses only one slot to provide up to four U-type BRI circuits.

Notes

●Each installed RBUU or RBUS circuit provides a 2B + D connection and uses a system capacity of two station ports and two CO lines regardless of the circuit application, even if the circuit is not actually connected.

Strata CTX ISDN Reference Model

A block diagram of the Strata CTX ISDN PCBs and reference points is provided in Figure 7-1.

R

CTX (NT2)

Demarcation Point

SLT

DKT

S

TE-1-S

(Voice or Data)

SLT R TA-S

PC

U

RSTU

PDKU

RBSU/RBSS

(NTs (P-MP)

RBUU/RBUS

RBSU

BPTU or

RPTU (TE)

U

T

NT1

CSU

(NT1)

Dealer- supplied CSU and NT1

RJ48C	BRI	Loop
8-wire		Termination

				ISDN
	RJ48C	BRI	Loop
				SWITCH
	8-wire		Termination
	RJ48C	PRI	Office
	8-wire		Channel
			Unit
Telco-
supplied
Jacks			Office Channel Unit, or OCR, is
			the CO Channel Service Unit

TE-1-U

(Voice or Data)

SLT	R
	TA-U

RBUU/RBUS (LT)

(P-P)

PC

R, T, S, and U are ISDN standard reference points

6643

TE-1 = Terminal Equipment, Type 1	P-P = Point-to-Point
TA = Terminal Adapter	P-MP = Point-to Multipoint
	(passive bus)

Customer Premises Equipment

Public Switched Telephone Network (PSTN)

Figure 7-1 ISDN Reference Model

7-2 Strata CTX I&M 06/04