Yealink SIP-T54S Administrator's Manual page 695

Configuring Advanced Features
Parameters Permitted Values Default
Description:
Configures MWI subscribe expiry time (in seconds) for account X.
The IP phone is able to successfully refresh the SUBSCRIBE for message-summary events
before expiration of the subscription dialog.
X ranges from 1 to 16 (for SIP-T54S/T48G/T48S/T46G/T46S/T29G)
X ranges from 1 to 12 (for SIP-T52S/T42G/T42S)
X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G)
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
X is equal to 1 (for SIP-T19(P) E2/CP860/CP920)
Note: It works only if the value of the parameter "account.X.subscribe_mwi" is set to 1
(Enabled).
Web User Interface:
Account->Advanced->MWI Subscription Period (Seconds)
Phone User Interface:
None
account.X.subscribe_mwi_to_vm 0 or 1 0
Description:
Enables or disables the IP phone to subscribe the message waiting indicator to the voice
mail number for account X.
0-Disabled
1-Enabled
If it is set to 0 (Disabled), the IP phone will subscribe the message waiting indicator to the
account X.
X ranges from 1 to 16 (for SIP-T54S/T48G/T48S/T46G/T46S/T29G)
X ranges from 1 to 12 (for SIP-T52S/T42G/T42S)
X ranges from 1 to 6 (for SIP-T41P/T41S/T27P/T27G)
X ranges from 1 to 3 (for SIP-T40P/T40G/T23P/T23G)
X ranges from 1 to 2 (for SIP-T21(P) E2)
X is equal to 1 (for SIP-T19(P) E2/CP860/CP920)
Note: It works only if the value of the parameter "account.X.subscribe_mwi" is set to 1
(Enabled) and "voice_mail.number.X" is configured.
Web User Interface:
Account->Advanced->Subscribe MWI To Voice Mail
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