Ext out of house

I have just installed Freepbx on my network all local ext are working.
But I have 4 external ext coming in over the internet, Thay are shown as loged in and I can all to and from them ok.

But the is no voice on the channel.

When you pick up the phone you get a tone call the number and the ext rings but when you answer the phone the line is connected but dead.

I am using the grandstream 486 ata.


I would look in your firewall settings and make sure SIP ports are open. In your extension config, enable nat=yes and qualify=yes for the external extensions.


As well as forwarding the ports as above, you might want to try changing the stun settings in the grandstream as these will have a bearing on remote extensions.