Meraki Wireless Network and WiFi Calling

[Frangipani]

Hello everyone. I'm getting reports of WiFi Calling not working consistently from users. The location where WiFi Calling is needed has very poor AT&T cell service inside the building. Our Wifi network is solid with excellent coverage. I have checked the phones that have reported issues and all settings are correct for Wifi Calling. Some of the issues when calling are, not being able to place a call, call going straight to voicemail, or texts and emails coming through if a cell signal is found by phone. Just was wondering if anyone else has had this issue. It is intermittent and not a consistent problem. Im working with AT&T(getting nowhere, go figure) and Meraki(analyzing pcaps)

[PhilipDAth]

Have you checked your firewall to see if it is reporting that any traffic is being blocked?

[Macguy]

Sounds similar to our issue we've been having throughout the year.  We first tried enabling QOS in SSID traffic shaping with default rules (which prioritize voice) per Meraki Support.  That didn't work.  The issue was our firewall (and typically is in most cases).  We have a Fortigate and by default it has a UDP Flood protect enabled under IPv4 DoS Policy.  We had to adjust the threshold to a much larger amount.  No wifi calling issues after.  The other issue which really can't be resolved is forcing wifi calling as a priority on the devices.  On Android you can set priority, not on iPhone.