Secure VoLTE and VoWiFi calls with GrapheneOS?

sappy_junior728

I'm new to GOS and I know I should use Signal, which I do, but I do need to make traditional phone calls from time to time.I've read that when using VoWiFi calls on both iOS and Android, even if I use a VPN, the OS will force the call to operate outside of the VPN tunnel. Can GOS get around that and force the VoLTE and VoWiFi call to go through the VPN tunnel? My fear is an MtM attack even if I have 2G disabled. If this isn't good enough, will using a router with a VPN force a VoWiFi call to go through a VPN tunnel?

dc32f0cfe84def651e0e

sappy_junior728 Can GOS get around that and force the VoLTE and VoWiFi call to go through the VPN tunnel?

No. Set up VPN on the router side instead, will help with VoWiFi.

wizoatk

sappy_junior728

You likely misunderstand. The content already goes through an IPSEC tunnel between your phone and your carrier. Putting that through an additional VPN adds no security. Arguably the only things that adding a VPN to this is to hide that you are using a specific mobile carrier from your ISP and hiding your IP address from your mobile carrier. It will also likely reduces reliability of connection and voice quality on the calls.

sappy_junior728

dc32f0cfe84def651e0e

That's pretty disappointing. Is this a limitation of AOSP and not even GOS can get around?

So can we safely conclude that VoWiFi over a router like with OpenWRT and a VPN is likely the most secure solution for a traditional phone call? Interestingly, I think I saw a thread over at PG that disagreed with this.