All cercuits are busy now. Please try your call later

Yestuarday I’ve got a trouble with Asterisk. It has no incoming and outgoing calls. 1 week ago it was works great. But now… We have no support team at location. As me, I’m noob in linux. At outgoing calls it plays a playback: “All circuits are busy now, please try your call later”. And if we do a call to intire port 7000 it plays recorded playback - it’s good. But still no incoming calls and outgoing calls. Oh guru people. Help me, please. What should I do to solve that trouble?

Provide useful debugging information. Verbosity 5 logs, for a start. Be prepared to provide your configuration files, as well.