Introduction and Description

LED Indicators

The ten LED indicators on the front panel (see figure below) of the MTA128ST/NT report status and line activity.

TD Transmit Data

Flashes when data is being transmitted (on for a space, off for a mark).

RD Receive Data

Flashes when data is being received (on for a space, off for a mark).

LS Link Status

For EuroISDN NET3, INS64, and VN4 switch protocols, lights when the TA is turned on. For US NI-1, DMS-100, and AT&T 5ESS switch protocols: On Steady, Link with central office is established (requires correct configuration of SPIDs) Flashing, Physical layer is down or one or both SPIDs have not been verified with central office

B1 Bearer Channel 1

When lit, indicates active data or voice connection on bearer channel 1.

B2 Bearer Channel 2

When lit, indicates active data or voice connection on bearer channel 2.

TR Terminal Ready

Lights to indicate that the computer is communicating with the MTA128ST/NT, so the MTA128ST/NT can answer an incoming call.

OH Off Hook

Lights when analog equipment on AUX port is active or off-hook.

128128 Kbps

Lights to indicate that the B channels have been multiplexed into a single 128 Kbps communications link.

P1 Data Protocol

Lights in combination with P2 and 128 LEDs to indicate which data protocol (V.110, V.120, X.75, PPP, MLPPP) is in use as shown in the table below.

P2 Data Protocol

Lights in combination with P1 and 128 LEDs to indicate which data protocol (V.110, V.120, X.75, PPP, MLPPP) is in use as shown in the table below.

MTA128ST/NT

8