Hello, we have a SV9100 system that has been switched over to SIP. Incoming and outgoing calls worked for a couple of days and then all of a sudden all incoming callers receive a busy response. Our VOIP provider is seeing a 486 BUSY response when our main number is called. Nothing was changed between the time where everything worked and when the busy response started happening. We can call our pilot number and the call goes through to the auto-attendant just fine. Currently our main number is camped on top of the pilot which is a temporary work around. Does anyone have any thoughts on where I can look to try and resolve the issue? Thanks!