Time out

Not sure Whats happening but I am not able to make calls.
Nothing has changed on my system that i am aware of, Tried to reboot pc and router.
Other than sip show peers is there somthing else i can check?

fpbx-1-1******/1SRDT 192.159.66.3 N 5060 OK (166 ms)
fpbx-2-*******/1SRDT 66.243.108.101 N 5060 UNREACHABLE
4 sip peers [Monitored: 1 online, 3 offline Unmonitored: 0 online, 0 offline]