Asterisk strange behavior - not ringing from ext to int


we’re using nat and our external phones are set to yes and internal to never.

i have set up the environment and everything was fine until i notice that if i call someone the phone doesn’t ring on the other end , SOMETIMES (most of the times).

But asterisk console says (201 dialed) and goes to voicemail.
however after awhile it starts ringing on the other end withot any change on the network and asterisk server. maybe bandwidth.?

it always works when i can from an external phone to the internal.

Have you seen this? I haven’t done anything to the system and it starts working.

Any help would be appreciated.

Have a nice day


the subject was incorrect.

this is the correct one:
Asterisk strange behavior - not ringing from INT to EXT