We have a complaint from callback system users that when they return a 603 Declined to us (on DID peered calls) we continue to send retries to them.
This results in multiple callbacks being initiated to their user/caller.
When our system rejects a call to firstname.lastname@example.org it receives a new call from the same number almost immediately. It means that either the caller redials immediately after getting busy tones (that is
unlikely) or the DID provider (This is us) does not properly support ‘603 Decline’.
From the SIP RFC:
21.6.2 603 Decline
The callee’s machine was successfully contacted but the user explicitly does not wish to or cannot participate. The response MAY indicate a better time to call in the Retry-After header field. This status response is returned only if the client knows that no other end point will answer the request.
Therefore the calling side (DID provider) should stop trying to deliver the call, but they do not. You can forward this explanation to them that should be enough for understanding the issue.
Is there a simple way to prevent retries being sent in this instance?
we are using asterisk 1.6 and 1.8 versions, with asterisk realtime.
any tips would be exteemily welcome.