Yealink SIP-T28P - Manual (Page 141)

Advanced Phone Features
129
The MWI Subscription parameters you need to know:
Options Description
Subscribe for MWI Enable or disable a subscription for MWI service.
MWI Subscription Period
Period of MWI subscription. The IP phone sends a
refresh SUBSCRIBE request before initial SUBSCRIBE
expiration.
Subscribe MWI to Voice
Mail
Enable or disable a subscription to the voice mail
number for MWI service.
To use this feature, you should also configure the
voice mail number.
Note
To configure subscribe for MWI via web user interface:
1. Click on Account.
2. Select the desired account from the pull-down list of Account.
3. Click on Advanced.
4. Select Enabled from the pull-down list of Subscribe for MWI.
5. Enter the period time in the MWI Subscription Period (Seconds) field.
Whether the phone sends SUBSCRIBE messages for MWI service to the account or the
voice mail number depends on the server. Contact your system administrator for more
information.