I can make calls, but cannot receive incoming calls.
I am using a HUAWEI B316 modem with an analog phone directly connected.
SIP ALG is switched off.
I note similar complaints where the number is not correctly assigned to your trunk and you fix it on the bank end.
I will need to submit a query to our service provider regarding the MTN calls not connecting to your number. I will give you feedback regarding this query asap.