Message Waiting notifications in SIP are done with the notify method.

This is supported by

• Atcom phones AT-320
• Aastra phones 480i, 9133i, 9112i, 480i CT Cordless
• D-Link phones DPH-120S
• Cisco phones
• Citel handset gateway phones
• Sipura SPA-841 phone and SPA-1001, SPA-2000, SPA-2002, SPA-2100, SPA-3000 adapters
• Grandstream phones
• Asterisk: The Open Source PBX
• Sayson phones 480i, 9133i, 9112i, 480i CT Cordless
• SNOM: Snom phones
• Zultys: Zultys phones
• Clipcomm phones

The mailbox directive in the sip.conf needs to be set and pointing to the correct context for this to work (example: "mailbox=1234@context").

The 480i, 9133i, 9112i, 480i CT Cordless phones need RFC3842 compliant From: headers in the NOTIFY for MWI to work. In some Asterisk setups, <sip:@192.168.0.101> is sent, and this causes the message to be discarded. One reason for this can be an empty callerid= line in sip.conf. In such cases, a workaround is to put fromuser=sipphone (or any string) in sip.conf for any user with a mailbox. Use Asterisk 1.0.4 or later to avoid MWI-issues.

See also

• RFC 3842: A Message Summary and Message Waiting Indication Event Package for the Session Initiation Protocol (SIP)
• MWI
• SIP
• PBX features
• RFC 3265: SIP-Specific Event Notification

• SIP | SIP method Notify | VOIP Phones