Meaning of "487 Request Terminated"

Question

Please tell me when a SIP call return 487 Request Terminated? Is it a termination issue?

Answer 1

The 487 Response indicates that the previous request was terminated by user/application action. The most common occurrence is when the CANCEL happens as explained above. But it is also not limited to CANCEL. There are other cases where such responses can be relevant. So it depends on where you are seeing this behavior and whether its a user or application action that caused it.

15.1.2 UAS Behavior==> BYE Handling in RFC 3261

The UAS MUST still respond to any pending requests received for that dialog. It is RECOMMENDED that a 487 (Request Terminated) response be generated to those pending requests.

Answer 2

It's the response code a SIP User Agent Server (UAS) will send to the client after the client sends a CANCEL request for the original unanswered INVITE request (yet to receive a final response).

Here is a nice CANCEL SIP Call Flow illustration.

Answer 3

Although , I am a decade late, but here's what we experienced. This means you are blacklisted. In India when we dial a DND numbers we get this code. Hope this help.