@david551 is correct. Look outside of Asterisk and confirm that the network connection itself is fine. The problem in Asterisk is a symptom, not the problem.
I identified the real trouble time after. It problem was caused by the ISP Provider’s DNS.
I used another DNS server and finally the system could worked correctly.
Please, somebody knows about the function of DNS in Asterisk?
I need to understand this, if you have documentation please share me. thank you.