Avaya 1600 manual USI Cables, DTE or DCE?, Which Hardware Protocol?

D. USI Cables

DTE or DCE?

A Data Terminal Equipment (DTE) device transmits data on the transmit pin and receives data on the receive pin, while a Data Communication Equipment (DCE) device transmits data on the receive pin and receives data on the transmit pin. Usually, the DCE device supplies the transmit clock timing for both the DTE and DCE devices.

You must use a straight through cable to connect a DTE to a DCE device. However, you must use a null modem cross over cable to connect two DTE devices or two DCE devices.

For example, the serial port on a PC is a DTE device, while most modems are DCE devices. To connect a PC to a modem, you use a straight through cable. To connect two PCs together, you use a null modem cross over cable.

Which

Hardware

Protocol?

You can configure the USI port on the PARTNER ACS 1600 DSL module for V.35 or RS-530. Each of these hardware interfaces uses different voltage levels, so they are not compatible electrically.

However, there are other hardware interface standards that use the same voltage levels, but with different connectors:

RS-449 and V.36 are the same electrical interface as RS-530.

The DB25 connector, which must be shielded, is wired for RS- 530, which is a superset of all the other hardware interfaces. Only RS-530 uses DB25 connectors - the other hardware interfaces use different types of connectors.

Avaya, Inc. - 190 - PARTNER ACS 1600 DSL module User Guide