We have a bunch of FreePBX servers running on-premise at different client locations - a mix of hardware and firewall brands, currently no issues with any of them.
We just built our first server in the cloud using a known cloud hosting provider. Recently the customer for this server told us that some callers reported getting a fast busy signal and then the call dropping a few seconds later. Nothing appeared in our FreePBX/Asterisk logs nor have I ever heard FreePBX/Asterisk giving a fast busy. We opened a ticket to our SIP trunk provider who told us that they see the failed calls, and that our server never responded or accepted the connection.
Based on the above, including our experience with our on-premise servers, we suspect the issue is with the cloud host. We’ve opened a ticket with them and are working with them, but it’s early and I feel like this might be difficult to diagnose. Our plan is to build a bunch of FreePBX servers in the cloud for our clients, but we need to resolve all issues and have a clean, issue-less few months before we are convinced this is a viable solution.
My question is, has anyone else experienced similar issues with a SIP provider intermittently not getting a successful connection to a cloud server, and if so, what issue was uncovered as the cause?