The following instructions cover the workarounds that have to be specified in order to enable MOH and MWI features on the Linksys SPA phones.
Navigate to *Devices -> Phone Groups and select the phone group you wish to change group wide settings on.
Navigate to the *Call Feature Settings page and click Show Advanced Settings.
Specify the *MOH Server to be ~~mh~@domain.com where domain.com is your actual sipx domain. Check the Message Waiting box.
Specify the *Mailbox ID as $USER_ID.
Click *Apply or OK to save changes.
Navigate to *Devices -> Phones and select the Line or Extension you wish to change settings on. In this example the Line was 168.
Navigate to the *Call Feature Settings page and click Show Advanced Settings.
Specify the *MOH Server to be ~~mh~@domain.com where domain.com is your actual sipx domain.
Check the *Message Waiting box. Specify the Mailbox ID as $USER_ID.
Specify the *Voice Mail Server to be extension@domain.com where in this example its 168@domain.com.
Click *Apply or OK to save changes.