Management communication consists of tags of the form "header: value", terminated with an empty newline (\r\n) in the style of SMTP, HTTP, and other headers.
The first tag MUST be one of the following:
- Action: An action requested by the CLIENT to the Asterisk SERVER. Only one "Action" may be outstanding at any time.
- Response: A response to an action from the Asterisk SERVER to the CLIENT.
- Event: An event reported by the Asterisk SERVER to the CLIENT