Unable to call via Apple WiFi Calling

03/26/2020 113 17456

DESCRIPTION:

Apple mobile devices are unable to use Apple WiFi calling to call regular phone numbers (the called phone rings but the call is dropped right away)

CAUSE:

Apple WiFi calling uses a IPSec VPN connection on UDP port 500/4500 to connect the call.

By default the Sonicwall will treat these packets like regular packets and change the source port during the NAT: this causes the call to be dropped.

RESOLUTION:

In order to make Apple WiFi calling work we need to change this default behaviour by enabling the option "Preserve IKE Port for Pass Through Connections"

NOTE: The location of the option depends on the firmware version.

1. Go to VPN | Advanced and look for the option "Preserve IKE Port for Pass Through Connections"
   • If present, enable the option and click on accept.
   • If the option is not present you need to open the hidden diag page by replacing main.html in the browser address bar with diag.html and then press enter.
     • Now click on "Internal Settings" and scroll down to the "VPN Settings" section.
     • Enable the "Preserve IKE Port for Pass Through Connections" option here and then scroll back up and press "Accept"

NOTE: This solution works most of the time but if the issue is not solved, please contact our Technical Support as there could be other misconfigurations/variables to take into consideration.