After months with no problems, I've recently begun experiencing issues. I can make calls, but not receive them. I can see that I'm registered from both the PBX, and freephoneline status. Incoming calls show up on the freephoneline call logs, but not the logs on my PBX. I'm registered to voip.freephoneline.ca with an expiry of 3600s. Incoming calls will go directly to voicemail or followme number. I've tried re-registering, but it doesn't help.
Edit: Switching to another server solved it.