I have a CUE system. Recently we have starting having issues when callers try and dial out periodically they will get a fast busy. These would be for PTSN FXO calls. Basically they dial 9+number and get fast busy. They can do it again and call will go through. We have tested PTSN lines and they are all good.
I did do a show voice port summary front he cli and I notice that calls that go through will show up as off-hook on voice port but if it rings busy all voice ports will be on hook so I am suspecting that the call isn't reaching the FXO port when the caller gets a fast busy. Not sure where to go from here in troubleshooting. Any help would be greatly appreciated!