I finally solved a really annoying Verizon WiFi calling issue that began with iOS 16 beta and continued through the official iOS 16 release. In short, it seems Apple changed something in their "keep alive" protocol for WiFi calling tunnels. I use a pfSense commercial router at home, and finally solved the problem using a trick employed for WiFi calling issues on several Android phones. Here's my post on the pfSense forum:
"Since installing the iOS16 beta, I have had intermittent "call failed" issues outgoing, along with intermittent incoming calls going straight to VM (Verizon WiFi calling). This persisted with the official iOS 16 release. I estimate I have issues about 40-50% of the time - very frustrating. My wife's iOS 15 iPhone 13 mini is working fine on WiFi calls, as was my iPhone on iOS 15.
I have reset network settings, done a factory phone reset and restore, changed every possible phone cellular setting, switched from physical to e-sim, and various other fixes - nothing worked.
Yesterday I changed my pfSense System/Advanced/Firewall and NAT/"UDP Multiple" timeout from 60 sec to 900 sec and it seems to have solved the issue! Over 24 hours with no WiFi missed calls or outgoing call issues."
This seems to be a setting that controls the time a UDP tunnel is kept open. Many Android phones struggle with WiFi calling and the 60sec default, but until now iPhones seemed OK with it. Something seems to have changed in iOS 16. Changing it to the "Android" recommended 900sec solved the issue for me!
I was surprised others weren't reporting this really annoying issue, so I suspect it's something more common with advanced routers having more fine-tuning control parameters. I thought this was worth posting because I'm pretty sure others may run into this issue at home (or work...) and it wasn't easy to figure out...
"Since installing the iOS16 beta, I have had intermittent "call failed" issues outgoing, along with intermittent incoming calls going straight to VM (Verizon WiFi calling). This persisted with the official iOS 16 release. I estimate I have issues about 40-50% of the time - very frustrating. My wife's iOS 15 iPhone 13 mini is working fine on WiFi calls, as was my iPhone on iOS 15.
I have reset network settings, done a factory phone reset and restore, changed every possible phone cellular setting, switched from physical to e-sim, and various other fixes - nothing worked.
Yesterday I changed my pfSense System/Advanced/Firewall and NAT/"UDP Multiple" timeout from 60 sec to 900 sec and it seems to have solved the issue! Over 24 hours with no WiFi missed calls or outgoing call issues."
This seems to be a setting that controls the time a UDP tunnel is kept open. Many Android phones struggle with WiFi calling and the 60sec default, but until now iPhones seemed OK with it. Something seems to have changed in iOS 16. Changing it to the "Android" recommended 900sec solved the issue for me!
I was surprised others weren't reporting this really annoying issue, so I suspect it's something more common with advanced routers having more fine-tuning control parameters. I thought this was worth posting because I'm pretty sure others may run into this issue at home (or work...) and it wasn't easy to figure out...
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