AudioCodes Mediant 800B User Manual page 408


VoiceMailInterface

EnableVMURI
The device supports the following digital PSTN-based MWI features:

ISDN BRI: The device supports MWI for its BRI phones, using the Euro ISDN BRI
variant. When this feature is activated and a voice mail message is recorded to the
mail box of a BRI extension, the softswitch sends a notification to the device. In turn,
the device notifies the BRI extension and a red light flashes on the BRI extension's
phone. Once the voice message is retrieved, the MWI light on the BRI phone turns off.
This is configured by setting the VoiceMailInterface parameter to 8 ("ETSI") and
enabled by the EnableMWI parameter.

Euro-ISDN MWI: The device supports Euro-ISDN MWI for IP-to-Tel calls. The device
interworks SIP MWI NOTIFY messages to Euro-ISDN Facility information element (IE)
MWI messages. This is configured by setting the VoiceMailInterface parameter to 8.

ISDN PRI NI-2: The device support the interworking of the SIP MWI NOTIFY
messages to ISDN PRI NI-2 Message Waiting Notification (MWN), sent in the ISDN
Facility IE message. This is applicable when the device is connected to a PBX through
an ISDN PRI trunk configured to NI-2. This is configured by setting the
VoiceMailInterface parameter to [9].

QSIG MWI: The device supports the interworking of QSIG MWI to IP (in addition to
interworking of SIP MWI NOTIFY to QSIG Facility MWI messages). This provides
interworking between an ISDN PBX with voice mail capabilities and a softswitch,
which requires information on the number of messages waiting for a specific user.
This support is configured using the TrunkGroupSettings_MWIInterrogationType
parameter (in the Trunk Group Settings table), which determines the device's handling
of MWI Interrogation messages. The process for sending the MWI status upon request
from a softswitch is as follows:
1. The softswitch sends a SIP SUBSCRIBE message to the device.
2. The device responds by sending an empty SIP NOTIFY to the softswitch, and
then sending an ISDN Setup message with Facility IE containing an MWI
Interrogation request to the PBX.
3. The PBX responds by sending to the device an ISDN Connect message
containing Facility IE with an MWI Interrogation result, which includes the number
of voice messages waiting for the specific user.
4. The device sends another SIP NOTIFY to the softswitch, containing this MWI
information.
5. The SIP NOTIFY messages are sent to the IP Group defined by the
NotificationIPGroupID parameter.
When a change in the status occurs (e.g., a new voice message is waiting or the user
has retrieved a message from the voice mail), the PBX initiates an ISDN Setup
message with Facility IE containing an MWI Activate request, which includes the new
number of voice messages waiting for the user. The device forwards this information
to the softswitch by sending a SIP NOTIFY.
Depending on PBX support, the MWIInterrogationType parameter can be configured
to handle these MWI Interrogation messages in different ways. For example, some
PBXs support only the MWI Activate request (and not MWI Interrogation request).
Some support both these requests. Therefore, the device can be configured to disable
this feature or enable it with one of the following support:
•
Responds to MWI Activate requests from the PBX by sending SIP NOTIFY MWI
messages (i.e., does not send MWI Interrogation messages).
•
Send MWI Interrogation message, but don't use its result. Instead, wait for MWI
Activate requests from the PBX.
•
Send MWI Interrogation message, use its result, and use the MWI Activate
requests.
User's Manual
Mediant 800B Gateway and E-SBC
408 Document #: LTRT-10278