MTNL FTTH Mumbai has call receiving issue

Messages
1
Location
Mumbai
ISP
MTNL
I have recently migrated from copper line to FTTH in MTNL Mumbai. I find internet is very stable while I am not receiving telephone call. If I call then it is completely noise free. If my number is called then the connection is not made. Any handle to resolve the issue? Thanks in advance.
 
Messages
9
Location
india
ISP
Airtel
What is the model no. of your ONT ?