I have a 3CX server running version v9.0.13545.594 SP2. I will be updating it to SP5 this week. Currently, we are having an intermittent issue where all fax numbers go busy, while other DID trunks work normally. The quick fix apparently has been to reset the 3CX server and fax numbers answer normally again. This state presents itself about every 2-3 weeks. I didn't find anything on the forum that describes a scenario such as this, so wanted to through it out to see if anyone else has seen similar issues with Fax. I've increase the logging from Minimum to help identify this issue. My apologies for a lack of details, I'm new to this application and this customer. Hoping to have much more detail for the next time it rears its ugly head, include a packet capture.