Some endpoints become unreachable but they (those phones) look registered


#1

On-premise box, behind NAT registered to the Trunk provider but some of the phones become unreachable.
When you look at these unreachable phones (Cisco 525g) they appear registered.
Any suggestions as to why?


#2

What are you looking at where it’s showing they’re registered? For example, is it some status screen on the phones, or something on the PBX? Are the phones behind the NAT as well? If not, do the phones become reachable after a reboot? If so, I’d look to see if there are any registration interval settings on the phones that can be reduced. For example, if they’re set to 1 hour, I’d try something lower like 2 minutes.