I have setup a router with the basic setting, I have found a very nice video on Youtube, now everything work fine except that when I try to connect a SIP phone, an Asterisk phone system or a simple Free Soft phone none will connect to the Voip provider.
If I take the soft phone and run it on a different network it works right away, I have open a hairpin NAT from outside to the Asterisk server connected to the Mikrotik router, I have connection and sound but the ANY SIP connection from inside the Lan is unable to connect to the Voip Provider.
I am able to ping the provider from a terminal in Mikrotik and from the terminal in Asterisk server. I see that Asterisk reach the Voip provider but it can't establish the connection. It is like any UPD connection is drop.
The video on Youtube is from ISP Supplies, very good video by the way.
Here is the video that I have watch on Youtube https://www.youtube.com/watch?v=ulDefmf1ces