For the EdgeRouterX, SIP ALG must be disabled from the command line.
To access the command line from the GUI of the EdgeRouterX, use the CLI button in the top-right corner of the GUI. Alternately, use an SSH tool to SSH to the IP of the EdgeRouter. Once at the CLI, enter the following commands:
set system conntrack modules sip disable
Additional configuration may be needed beyond these steps. Contact Ringfree for more information.