What is MWI?

MWI (Messaging Waiting Indication) is a common feature of telephone PBX systems. It typically involves an audible or visible indication that messages are waiting such as playing a special dial tone (called a message-waiting dial tone), lighting up a button or displaying icons or text on the telephone handset.

VigorIPPBX 2820 supports MWI. With this feature when someone leaves you a voice message, a special tone (MWI tone) will be played while you pick the phone up to let you know that you have a voice message. After hearing the tone, you will then hear the normal dial tone. You can then choose to listen to the voice message or call someone back.

Example for using MWI

The following example shows the benefits of using MWI. Generally, Jacky uses a mail client to receive voice mails but it’s not always convenient to manually check voice mail via mail client. If not checked, there is a possibility that voice mails may be dropped or deleted by an accident due to something like an Antivirus scan. To avoid this possibility, Jacky also uses MWI feature of VigorIPPBX 2820 to be alerted of missed phone calls.

Configure MWI for Jacky’s Extension

1. Open the extension profile for Jacky. Below is an explanation of the basic configuration. Jacky’s Extension Number is 211. Display Name is locally significant for identification. Make sure the Type is SIP. Enable Authentication and type a Password for this extension. Input an E-mail address for Jacky to receive voice mails.

2. Select either Notify User who Subscribed or Force Notify User for MWI.

Voice mail Password:

If you want to listen to the voice mail by phone via VigorIPPBX 2820, you must set a voice mail password to prevent someone unauthorised from also hearing it. To check voice mail, users will need to first enter their voice mail password.

Notify User who Subscribed:

Most IP Phones support MWI feature. You can enable or disable it as required. When Notify User who Subscribed is selected, VigorIPPBX 2820 will send MWI to the IP phone with MWI enabled. However, if the IP phone does not have MWI enabled, the VigorIPPBX 2820 will not send MWI to that IP phone.

ForceNotify User:

When Force Notify User is selected, VigorIPPBX 2820 automatically sends MWI to the clients when there is voice message whether the IP phone has MWI enabled or not.


Additional Configuration for Voice Mail

Go to the IP PBX >> PBX System >> Voice Mail Configuration page and configure the following items


Extension for checking messages: If you want to listen to a voice mail, you need to dial the number which is set in the field of Extension for checking messages. The default value is 888. You can change it manually.

Day for keeping voice mail: Means the time for keeping a voice mail in VigorIPPBX 2820. The default value is 3 (days). After this time, the message will be deleted automatically.

Send Voice Message by Email: Tick it to enable the voice mail function.

Delete Voice Message after Sending Mail: If you are using MWI, do not enable this option. No MWI notification will be sent after a voice message is deleted.



1. Mike calls 866669@iptel.org and dials extension number 211.

2. Jacky is not available at that time

3. Mike leaves a message to Jacky, then hands up the phone.

4. Jacky is free and picks up his phone.

5. Instead of the normal dial tone, Jacky hears a special tone (MWI tone) which implies that he has a voice message. After listening the special tone, Jacky will hear the normal dial tone.

6. Jacky dials 888 and input the voice mail password to hear his voice message.