Once on one Asterisk server I noticed the following error:
NOTICE[12822][C-00007087] app_dial.c: Not accepting call completion offers from call-forward recipient Local/096xxxxxx@sip-dialout-000004d1;1
I will describe the situation, the call came to the Goip4 gateway, in which there were two SIM cards of one mobile operator, on the IP phone the user turned on forwarding to his mobile number, the call went to through any of the SIM cards, as a result, when two incoming calls came to both SIM cards, then naturally an outgoing call cannot be made anymore, since both SIM cards are busy and this error was displayed in the logs.
Therefore, to solve this problem, I added a few more SIM cards.
See my other articles on the topic of Asterisk.