Based out of Austin TX, we have phones in other cities within the state from El Paso to Houston. Not to often the phones(Polycom IP550) sometimes just lose connection for 2-4 days sometimes. Then one day they just get connection again like nothing ever happened! I have those offices restart the phone and router to no avail on the first day when it happens. I also have folks that work from home that use PhonerLite through their PC with no issue that is not solved by restarting their PC or Router. This issue doesn’t occur here in the office with over 60 phones(Polycom IP550) in use here every day. I am still new to this system and was not the installer of it.
Let me know what more info is needed!
I assume the local phones are on the same subnet as the server?
The remote phones need a pinholes in the firewall to work. My guess is the remote firewall is aging out. Have you tried rebooting it?
The only way I know of to make this work reliably is to setup a VPN to your remote site. Most routers have the functionality built in.
The Yealink phones have OpenVPN clients and connect to the OpenVPN provided with the latest FreePBX distro.
I think I found the issue to be with DYN account. The IP addresses for the different phones that were outside of the home office, were changing at the carrier level(Time Warner, Comcast, so on…). Once I logged in and added the new IP at DYN.com under the appropriate account, it was fixed instantly.