AudioCodes Mediant 800 MSBG User Manual page 462

CallerIDType (determines the standard for detection of MWI signals)
ETSIVMWITypeOneStandard
BellcoreVMWITypeOneStandard
VoiceMailInterface
EnableVMURI
The device supports the following MWI features for its digital PSTN interfaces:
For BRI interfaces: This feature provides support for MWI on BRI phones connected to
the device and 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 extension turns off. This feature 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 supported by setting the VoiceMailInterface parameter to 8.
QSIG MWI: The device also supports the interworking of QSIG MWI to IP. This
provides interworking between an ISDN PBX with voicemail capabilities and a
softswitch, which requires information on the number of messages waiting for a
specific user. This support is configured using the MWIInterrogationType parameter,
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.
In addition, 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 the 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.
SIP User's Manual 462
Mediant 800 MSBG
Document #: LTRT-12804