I rebooted my CentOS server and after that I realize asterisk calls is no longer showing on CLI. Nothing is showing at all
Even after I have done #asterisk command and also tried other asterisk start command. All files and modules are still running. I dont know what else to do again
You need to be more descriptive. Are SIP calls not working at all? If so then that would be a different issue and you should narrow it down more, for example use tcpdump to see if SIP traffic is even arriving at your server. If not then on reboot firewall rules may have gone back into place to prevent it.