I’m new to asterisk. My asterisk version is 2.10.0.1. I found similar post in this forum, but the recommended solutions did not work for me. I have disabled the SIP ALG in the firewall (FortiGate). Please find the below debug when I make a test call from 0123534328 to 5612 extension (DID: 043761112).
Local IP: 10.161.162.29
Public IP: 1.9.35.227
Carrier IP: 203.121.94.6
It appears that this BBS uses the Twirtter convention that an at signs signals a reference to a user name. I presume that your quote includes these in SIP URIs. Whillst I’m not familar with this BBS software, I would try and see if either quote or preformatted blocks inhibit this. Otherwise simply edit the ats out of the file.