Overnight all of our 40+ desk phones stopped working. We have mostly a mixture of T32G and T48G. All of them connect using a SBC running on a Windows server. I have rebooted the server and also restarted all services on the 3CX managment console. Everything is green and running. I am concurrently checking to see if the WAN/Firewall group has made any changes. What other things should I be checking? Thanks in advance.