Originally it seemed after enabling WIFI calling it wasn't working, or appeared to work intermittently. Being that I am located in two primary locations all of which that have Meraki networking equipment, I suspect that to be the issue. I would notice it would work when tethered to an IPAD, or randomly so I didn't believe it to be a device issue.
Oddly enough after opening a ticket with Meraki, the packet captures showed that we were connecting via the following ports:
- TCP 5060-5061 (SIP)
- UDP 4500 (IPsec)
So I was at a loss as to why I would be connected but the iPhone wasn't showing the "VZW Wi-Fi" in the upper left hand corner. To Test, I went ahead an enabled airplane mode, then immediately enabled WIFI. Once I did that, the phone showed "VZW Wi-Fi". I placed a few test calls and all was well. After about 2 weeks of monitoring, I noticed that WIFI calling from the iPhone, at least on Verizon will not work unless your signal strength is weak. In the past on T-Mobile when you used UMA, or WIFI Calling it was always the priority. Appears that Verizon would prefer you on their network unless your signal is weak.
For those who don't believe it is working, or seems to only work intermittently, try the above test and you should find success.