Connecting To Isdn In North America; U Interface; S/T Interface - NETGEAR RT210 Reference Manual

Reference Guide for the Model RT210/RT211 ISDN Routers

Connecting to ISDN in North America

Your location is connected to the central switch at the telephone company by a two-wire U
interface, like the interface that is provided on the Model RT211 ISDN router.
If the Model RT210 ISDN router or any device that does not have a U interface is connected to an
ISDN line, the interface must be converted by using a network termination unit, known as an NT1.
The NT1 converts the S/T four-wire interface of the RT210 to a two-wire U interface.

U Interface

If you have purchased a NETGEAR Model RT211 ISDN router, which has a U interface
connection, you can connect to your ISDN line by connecting the flat ISDN cable from the ISDN
wall outlet into the port marked ISDN on the RT211 (refer to
can be set up to accommodate either an RJ-11 or RJ-45 connector.

S/T Interface

If you have purchased a NETGEAR Model RT210 ISDN router, which has an S/T interface
connection, you need an external NT1 to convert the S/T to a U interface.
To connect the ISDN line into the router (refer to
Connect the ISDN ribbon cable (2) from the ISDN S/T interface (3) on the NT1 device (5)
1.
into the ISDN port on the router.
Warning: Some NT1s provide 48 V DC on pins 7 and 8 of the terminal connector to
power ISDN telephones. Plugging the cable from an NT1 into the LAN port causes
serious damage to the router.
Connect an ISDN cable from the ISDN wall outlet (6) to the U interface (4) on the NT1
2.
device (5) .
Connect the NT1 device (5) to the AC power and turn the power on.
3.
2-8
Figure 2-1). Your ISDN wall outlet
Figure 2-2), follow these steps:
Installing and Connecting