Problem is gone Michael. I shutdown ipfire and after a while I start again, the system renew the public ip, I have a fiber optic connection, and voila I can register with voip provider.
The doubt that remains is: it was the isp blocking sip with ip assigned or the firewall needed a reboot.
Update: The problem is with voip provider, I lost the register again with my fiber connection and with the mobile hotspot connection.