Has anyone sucessfully made and received SIP phone calls, on Android, while connected to the VPN? I'm creating a WiFi only Android phone (No SIM card, Airplane Mode) and inputting all the open access points in my area, for a data connection. I have an OSTEL.co account, which allows for encrypted (ZRTP) SIP phone calls, using the CSIP Simple application. It also interfaces with Jitsi on the desktop. I want to activate the VPN before leaving the house, and make and receive phone calls. This all works great when using my bare home ISP connection, and on my carriers data network - but as soon as I connect to the VPN, I get nothing. Is this because I would need to forward ports in my Air account?