486 Busy here 30 seconds after lights out?

Question

Asterisk

Good afternoon. There was such problem
Outgoing call. The number is busy or disconnected. Goes:
180 Ringing
183 Progress
Somewhere here a person rejects a call without answering a
bunch of RTP with a callback,
but 486 Busy comes only after 30 seconds
at this time busy beeps are heard. Has anyone experienced this?
To look for a problem on your asterisk or to fuck the operator's brain?
Thank you in advance for your help

Answer 1

Faced this at Rostelecom

Answer 2

The problem is really simple. The server system waits 30 seconds for a connection confirmation. Most likely, ACK is not coming from your network equipment. Well, and accordingly, without receiving confirmation, the system breaks the connection, even if the conversation was going on at the moment. If you are using a router, try enabling UPnP support and disabling SPI.

Answer 3

Satrou is right, it also breaks the connection in this interval if it cannot establish RTP / codecs do not match / other similar problems / questions to the passage of nat. Debug will give everyone away.