We have a user that requires a phone outside of our office. The 3CX mobile & Windows app work outside of the LAN however the phone says "Network Unavailable." Initially I thought it might be the phone, we were trying to use an older Polycom IP650 and in the 3CX management portal it would only allow provisioning from the LAN so I switched it out with a Yeahlink T46G which allowed me to change the provisioning server to our external URL. I confirmed that both phones worked on the LAN before shipping them off however neither works when offsite. I checked my firewall config and the ports seem to be correct. Could someone give me some guidance? Thanks!