# Descriptions

Some integrations do not handle message waiting indicators (MWI) so NuPoint Unified Messaging provides MWI applications that allow the server to activate message waiting indicators on the PBX. These applications are:

- DTMF-to-PBX

- MiTAI

- RS-232 (modem-based, legacy application)

## DTMF to PBX Message Waiting Application

The DTMF-to-PBX MWI application allows the server to turn PBX message waiting indicators on and off by sending DTMF signals over the telephone lines. Some PBXs allow telephone users to turn message waiting indicators on and off by dialing in a code. If your PBX has this capability, and if the code is not sent using proprietary signaling, you may be able to configure the server to behave as if it were a station user.

When a message is left in a mailbox that uses this type of message waiting, the server takes a line-card port off-hook, dials a string of DTMF digits, then goes on-hook. The PBX translates these digits and turns the appropriate indicator on. When all unplayed messages have been played, the server follows the same procedure (dialing a different string of digits) to turn the indicator off.

## MiTAI Message Waiting

MiTAI MWI has similar behavior to the DTMF dialer but does not generate a dialing sequence and does not require a port. MiTAI MWI uses the proprietary MiTAI Messaging API to communicate directly with the MiVoice Business ICP to activate message waiting indicators on designated phones. Because the MWI does not actually dial out, outbound calls with the MiVoice Business ICP are reduced.

## RS-232 MWI (Legacy)

The RS-232 MWI application allows servers to turn PBX message waiting indicators on and off by sending signals to the PBX over RS-232 data links. The data links can be either direct serial connections to the PBX, or they can connect to modems that are connected to analog ports on the PBX.

When a message is left in a mailbox, the server sends an ASCII message that tells the PBX to turn on the message waiting indicator at the appropriate station. Conversely, when all unplayed messages are played, the server sends an ASCII string that directs the PBX to turn off the message waiting indicator.

Parent topic: Overview