Hi friend.
Please refer to the following steps:
Find the VAS profile of the ONT.
Select "Configuration" --> "AccessProfile Management".
Select "ONT VAS Profile" --> "General ONT VAS Profile".
Right-click the field under the“General ONT VAS Profile”, and then choose “Modify”.
Find the SIP -> SIP Digitmapof each user, and you could modify the parameters.
Click next and finish, then apply to the ONT.
I hope I can help you.