By default, VMWI function is enabled, user can go to SIP Account-->Line 1 page, Supplementary Service Subscription column to check.

If the VMWI service is enabled, when someone leaves a message, G801 will send a signal to the analog telephone, the phone will rings shortly, by default, the ringing time is 0.5 seconds. User can change the ringing time in Phone-->Preferences page, Preferences column.

Also, when someone leaves a message, one the telephone's LCD, it will displays message waiting(in Chinese, it is 留言待取）.

By enableing VMWI, user can check if there is or not a message via the two upon ways, it is more convenient than the MWI function.