I have a freepbx phone system 200 running asterisk 11.20.0. I installed 3 gxp-2160 phones in a location that we had to vlan and everything worked fine. About three days ago one of them went offline and did not come back up. I called the customer on his cell phone and ask him to reboot and he did and I could see it come back on the peers. Then I changed the registration time to 240...360...and 300 when I did this the phone started registering and unregistering at a consistent 3 minutes. Can someone help me????? I'm very obviously new to this.