User guide

User Guide for PBXLink DMI4

Call information is important to the voicemail system as illustrated in the following scenario:

John works at a company with a Mitel PBX and attached voicemail system.

John’s extension number is 1234

A call comes into John’s phone at extension 1234.

John is not at his desk and, after three rings, the call is automatically forwarded

by the PBX to the voicemail system.

At this point the voicemail system needs to know the original destination of the

call that has been forwarded to it, so that it can play the personal greeting for John

and put messages in John’s mailbox.

The DMI4 provides that information to the voicemail system, which can then determine which mailbox

greeting to play.

The DMI4 provides additional information, such as:

· - whether the call was transferred because John did not answer his phone (as in the above example),

because his phone was forwarded, or because he was already on the phone. The voicemail system can

then use this information to play different greetings.

· - the caller’s number, when available. The voicemail system can use this to allow users to reply to

messages.

· - whether the call was directly to the voicemail system itself. This is useful to identify a voicemail

subscriber, so that when John is at his desk and calls the voicemail system to pick up his voice messages,

he only has to enter his password and not his mailbox number.

The DMI4 provides this information through its built-in COM port using the Centrex SMDI protocol. The

DMI4 also can also provide call information through inband tones, where DTMF tones are played to the

voicemail system to convey this information after an incoming call has been answered.

Another important function performed by DMI4 is to set and clear the message-waiting indicators on

subscribers’ phones. When a Message Waiting Indicator needs to be set, the voicemail system sends a

command to the DMI4. The DMI4 then uses the Message Waiting Indicator (MWI) features of the of the

emulated digital phone set to turn on or off the lights.

How the DMI4 Works

Please take a few minutes to read and understand this description of how incoming voicemail system calls are

processed. This will help enable you to make correct system configuration decisions later.