User Guide

ISDN Router Manual V.1.1

4. ISDN U-interface

Connect the U-interface with the attached RJ11 cable to the ISDN outlet installed by the local

PTT. Please consult your local PTT office for help in connecting the ISDN outlet .

5. U REV S.W.

Indicating the router had synchronized with the ISDN network. The LED blinks when the router

tries to synchronize with the ISDN network. When the synchronization is reached, the LED

stays still in on or off mode. Please note that the router has to be synchronize with the ISDN

network to establish external communication.

6. U ON/OFF S.W.

The ISDN technology allows up to 8 ISDN S/T devices to connect all together in the same S/T

bus to construct a multi-drop connection and let 8 S/T device sharing the same U-line. You can

set U OFF and connect ST2/ST1 port to other S/T bus to make multi-drop connection.

In case that your local PTT has provided a NT1 box already (one side connected to the ISDN

network with U interface, the other connected to user’s device with S/T interface), you just need

to connect the router with ST2/ST1 to the NT1’s S/T port. Please make certain the U switch is

set to OFF prior connection.

7. ST2,ST1

Providing two S/T ports to be connected by other ISDN S/T phone, Terminal Adapter for

constructing a multi-drop connection for sharing the same ISDN line resource. The S/T ports

should be connected with a right RJ45 cable.

8. T.R. S.W.

ON : set 100 ohm terminating resistance in S/T port (ST2/ST1)

OFF : set none

For ISDN multi-drop connection, it is suggested that one should make impedance match between

the NT1 and the farthest S/T device. If the NT1 was set to 100 ohm in its S/T port, (most of the

NT1 will set 100 ohm) then the farthest S/T device should be set to 100 ohm too to get impedance

match while all other S/T devices should not be set. If the NT1 was not set the 100 ohm

impedance, none of the S/T devices should be set the 100 ohm impedance.

9. Frame Ground

Connecting to the house’s safety ground pin for safety.