I live on a property that has zero cellular service. This forces me to rely on Wifi for calling, and texting. Only loosely related, but that means when I lose power, I cannot make calls, texts, or use the internet. For that reason, I wrote a separate blog post how I work around this, and still leverage the internet during power outages.

I’ve always founds Wifi calling/texting to not be as good as I had hoped. Often, I’d find my phone being unable to make or receive phone calls, or send or receive texts. This would happen without any indication, and I’d only discover that my phone was in this state by realizing I couldn’t initiate texts/calls, or be told by someone that they have been able to call me. While the phone was in this state, the caller would not hear a ring, and eventually just get sent to my voicemail. I’d often see a voicemail notification, but have never once got an indication of an incoming call.

When I couldn’t initiate call, the phone would display a popup and display something like “please disable Airplane mode to place a call”. Additionally, sometimes I could make calls, and hear the other party perfectly well, but they cannot hear me at all

This problem transcended phones, from a Pixel 4a, Pixel 8, to a Cat S22 flip phone.

I first started trying to solve this on the phone itself, but later moved to making changes on my router as well. both of these approaches allowed me to resolve all my issues.

Phone

Leaving my phone in Airplane mode was the single biggest phone side fix that I found. This forced the phone to explicitly rely on the Wifi, and not attempt to try to leverage the cell network.

Router

This was where the real changes were made. The hardware I’m using is:

The changes I made were in the Hardware Controller.

The first change I made was turning on “Fast Roaming” in “Organization Default > Site > Wireless Features”. This allows your phone to quickly change between different access points during a phone call, without interrupting the call.

The second change I made was turning on “VoIP Prioritization” in “Organization Default > Settings (bottom left gear) > transmission > Gateway QoS > VoIP Prioritization”. This ensures that the router treats your Wifi call with a high priority, further ensuring that there’s no interruption to your call.

The third and final change I made was disabled “SIP ALG”. Many people online describe how this change really ensures Wifi calling is not interrupted. I’m not well educated at this level of details, but it shocks me that this setting is on by default, as it allows the router to modify your Wifi calling packets, interrupting any calls. You can find this setting in “Organization Default > Settings (bottom left gear) > Transmission (left vertical bar) > NAT (left vertical bar) > ALG (tab)”.

Overall, these three settings should drastically improve your Wifi calling experiences.