Telos ZephyrExpress user manual What does the Isdn Cause phrase say?

You should also try the call at different bit rates (56/64 Kbps): that can affect how the call gets routed through the network.

What does the ISDN “Cause” phrase say?

This phrase or something similar will appear on the LCD after dialing. It comes directly from the telephone company equipment and can be valuable for troubleshooting. Gen- erally these phrases are self-explanatory.

Getting a Cause phrase means you are at least talking to the Central Office equipment. There is a full description of the phrases and their meanings later in this section.

Are you using the Zephyr’s internal NT1?

The green LINE DIRECT LED is on the rear panel, near the U jack of North American ZephyrExpress units. If there’s no ISDN line connected, or the line is dead, the light will blink rapidly (about 5 Hz). If NT1 can contact the central office, the light will blink slowly (about 1 Hz). The LED comes on steadily when all handshaking is completed and the basic line connection is good.

If the LED is off, or blinking slowly, there could be a problem with ZephyrExpress. Sometimes disconnecting the ISDN line and rebooting the system will fix things: when power is reapplied, the light should blink rapidly until you re-connect the line..

Are you using an external NT1?

If so, check the LEDs on the unit. The following indicators are typical, but not all NT1s will work this way.

•Power. Should be lit. In North America, power for the NT1 is normally provided by the terminal device; in this case, ZephyrExpress. Units sold in North America have both S and U interface jacks (and an internal NT1), and provide power over the 8-pin

wS interface cable. Elsewhere, power is normally provided by a separate NT1 power supply. Units sold outside North America have just an S interface jack, and do not provide power.WARNING!Do not power the NT1 from both ZephyrExpress and an external supply. If youÕre

using a North American ZephyrExpress and an external NT1, disconnect any other power supply.

•A blinking Power light usually indicates insufficient voltage.

•Active. Lights green when all is well.

TROUBLESHOOTING 9-17