Receive text messages via "wifi calling" on phone, over tor on openwrt?

Hi,

Unsurprisingly, it seems that my mobile phone provider utilises udp for wifi calling.

I would like to receive text messages over tor/openwrt.

Is this possible?

I assume there is no way around 'wifi calling' utilising udp (I do understand why they use udp rather than tcp for wifi calling. And i can think of a few reasons why udp traffic over tor is not a great idea as a rule. But i only want the ability to receive what would be a very small number of texts (although being able to send a similarly small number would be a welcome bonus). I am not looking to stream a lot of real-time data or anything.

Put simply, I am wondering if there is a way for me to enable udp traffic over tor/openwrt? Even if only on a temporary basis as I check for texts.

Thanks very much for any help.

Not specific to OpenWrt:

2 Likes

Hi thanks for these links.

I wonder if I can easily replicate the whonix > tor > vpn chain on my desired setup of phone > wifi to openwrt router > tor > vpn?

I see openwrt has an openvpn client luci app. I am basically new to openwrt but I wonder, is it as straightforward as getting tor working on my openwrt router, then installing the openvpn client and setting that up, taking into considerarion any relevant issues mentioned in your whonix links?

I don't think I have any way of routing wifi calling through a vpn that permits udp traffic but I guess a can find out.
Thanks again!

1 Like

What are you trying to accomplish?

The solution you are up to requires a VPN server "somewhere". You can pass the traffic from your OpenWRT to that VPN server through Tor in order to hide from your ISP the fact that you're connecting to that VPN server.

But if you put a cheap virtual server in a data center to act as your VPN counterpoint, you will have a contract with whoever rents this virtual server to you, and having a literal contract is pretty much the opposite of what one would use Tor for in the first place.

And you stop hiding your Wi-Fi calling traffic the second it leaves your newly acquired virtual server because it will always go through this very virtual server, no matter the route it takes through the Tor network.

In my opinion, you add as much traceability through the route from your VPN server to your mobile phone company as you reduce by adding Tor. Leaving a net-zero in traceability while still adding the bandwidth and latency limitation Tor always comes with.

So, given the fact that you most likely will not be able to pass Wi-Fi calling traffic through Tor directly and thus will require some sort of static network counterpoint on the other side of the Tor network, what's the benefit you hope you will get here?

It might be worth considering to just make Wi-Fi calling traffic not go through Tor. I'd just exclude UDP traffic on ports 500 and 4500 (regular IPsec+IKEv2) and be done with it.