So this is the 3rd time this has happened to me, first time when initially installing the PBX, then the other day I went to enable fax detection, after I enabled it I was no longer able to make or receive any calls. All circuits were busy for outgoing and incoming was going to our fail-over. I had to contact our provider (Windstream) and after them initially saying that the line was testing clean, I told them that this previously happened and the guy re-sync the line and we were back up. However thinking it was something with the fax detection I disabled it while they were doing that. So I just re-enabled fax detection and I am having the same problems. I contacted them again to re-sync the line, but this time I am going to leave fax detection enabled. My question is does anybody know what would be causing this?