Controllerless Networks

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Wifi Calling Verizon not working IAP 225

WiFi calling for Verizon isn't working when connected to my IAP 225 running; however, it will work when connected to a Desktop hotspot connected to the same network. I've taken a few packet caps, 1 at the router showing the failure, and 1 using the desktop hotspot showing a successful connection to wifi calling.

Success Desktop AP.PNGDesktop AP SuccessRouter Failing.PNGIAP 225 Failing

Aruba Employee

Re: Wifi Calling Verizon not working IAP 225

It looks like possibly an MTU related issue.


From the desktop AP, the SA_INIT starts, there's an initial Initiator Request that is responded to, so a retry with smaller payload. The setup continues with the smaller frame size.


On the AP225, the SA_INIT starts with a response back from Verizon, the client attempts to start with the larger frame size, but never retries with a smaller payload.

Charlie Clemmer
Aruba Customer Engineering
New Contributor

Re: Wifi Calling Verizon not working IAP 225

This was the issue. I have jumbo frames set on my router. Dropped the MTU to 1500 on all interfaces and wifi calling is back, even through it worked for 6 months before.

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