How to recognize a busy signal in Asterisk?

Question

Asterisk

Good afternoon, the task is to recognize from the traffic dump whether the caller received a busy signal and “3 short beeps”.
The dump shows that the subscriber does not receive a response 486, in the situation I simulated, when busy, the answer always arrived. Is it possible to conclude that the busy signal has not been sent to the subscriber?
And in general, where can I read about signaling with different answers?

Answer 1

"3 short beeps" you will not determine from the dump. This signal is generated by the phone in response to the corresponding SIP status. On many phones, the setting may vary depending on the installed region or custom pattern. Therefore, it is impossible to say exactly what the subscriber will hear in response to "486 Busy Here".