Posted: Fri Sep 30, 2022 16:25 Post subject: Does IPSec WiFi Calling work behind VPN routers?
Carrier-based WiFi calling uses IPSec and bypasses whichever VPN installed on phone, but what if the router itself is set to use OpenVPN or WireGuard? Would IPSec WiFi Calling go through router's OpenVPN/WireGuard tunnel without issues?
What are the issues and how can they be resolved while maintaining OpenVPN/WireGuard tunneling for all devices (including devices using IPSec WiFi calling)?
Tip: Use UDP rather than TCP. OpenVPN have end-to-end control build in. With TCP, you get double end-to-end control that can make packets be transmitted several times.
Thanks, I've already seen some of those threads, but I couldn't find anything specific in regards to IPSec WiFi calling running inside OpenVPN or WireGuard tunnel established by router. SIP and IPSec WiFi calling don't use the same protocols.
Joined: 04 Aug 2018 Posts: 1447 Location: Appalachian mountains, USA
Posted: Sat Oct 01, 2022 19:16 Post subject:
Just a datapoint: I use IPSEC wifi calling on my iPhone XS (iOS 16.0.2) every day over my router (WRT1900ACSv2, on build 49081) with no issues that I'm aware of. Seems fine with either OpenVPN or wireguard tunnels. In fact my typical day has me running the wifi-calling tunnel inside a wireguard tunnel that runs inside an OpenVPN tunnel. No problem.
Last edited by SurprisedItWorks on Sun Oct 09, 2022 22:13; edited 1 time in total
I found that for me, it's always the same IP. After adding PBR, never had any issue with WiFi calling. This way only IPSec goes through WAN and all remaining connections goes into VPN.
If you want to intentionally route even IPSec connections then choose the server closest to your location or the server location in order to keep the latency minimal.