Introduction and Description

If your ISDN product operates with a S/T outlet interface, you need an NT1 device to connect to the ISDN switch. MTA128ST adapters need an NT1 device to connect to the ISDN switch, but the MTA128NT adapter does not require NT1 device. In the UK, and in many European countries, NT1 device is supplied by your telephone company.

Point “S”

4-8 Wires

Terminal

NT2

Point “T”

4-8 Wires

 

 

(PBX)

 

Point “S”

NT1

Point “U”

2 Wires

 

Point “S”

Terminal

Terminal

Figure 2-1 ISDN Interface Points

S/T Interface

The S/T interface uses an 8-conductor modular cable terminated with an 8-pin RJ-45 plug. An 8-pin RJ-45 jack located on the terminal is used to connect the terminal to the DSL (Digital Subscriber Loops) using this modular cable.

Table 2-1 shows the Pin Number, Terminal Pin Signal Name and SILC Pin Signal name for the S/T interface.

Pin

TE Signal

 

 

1

Not used

 

 

2

Not used

 

 

3

Tx+

 

 

4

Rx-

 

 

5

Rx+

 

 

6

Tx-

 

 

7

Not used

 

 

8

Not used

MTA128ST/NT

6