WireGuard uses UDP and is effectively "connectionless" meaning there is no persistent connection to be maintained. It also allows for seamless IP address roaming (your peer doesn't care if two messages come from two different IPs so long as they are signed with the right key).

In short, I expect it to have no meaningful degradation when on a bad network (so long as they don't block the traffic or have overly hostile NAT).

That is exactly what I was hoping for.

Too bad it'll take forever before iOS can use it, because the current state of VPN on Wi-Fi is terrible (I understand that is not the first thing WireGuard is looking to solve, but it'll be great when it gets there).

ZeoTier, which also uses UDP, has an iOS app. So it is possible if the dev team wants to prioritize it.

It wasn't a whole lot of fun trying to connect code designed to operate at L2 (ZeroTier) with the L3 tun adapter they give you in iOS and Android. Fortunately that code doesn't have to be touched too often though :)

Fortunately WireGuard only encapsulates at L3, if I’m not mistaken :)

Is it open source?

I seriously recommend all to try zero-tier. Especially the fine-grained permissions control is fantastic. It is the only one that went so far as fool-proof.

The way WireGuard is designed should actually result in a more stable connection for the end user when the device is hopping between LTE and WiFi constantly.

There apps that can run as third party VPN providers on iOS. It's often used by corporate networks that use non-standard VPN protocols.

So there is hope. :-)

It’s great at roaming, but it is UDP; so if your bad WiFi doesn’t let you use egress UDP that won’t work. It’s pretty speedy though :)

I've found UDP over OpenVPN to work fairly well even on bad networks. Well-supported on iOS too with the OpenVPN Connect app.

It does until it doesn't. Then you have to wait X seconds for a keepalive (one of the 100+ configurables) to notice you're not passing traffic, and your client to tear down the dead tunnel and reconnect. Meanwhile many other applications have also lost connection to endpoints and need to do the same type of reconnection.

Stateless is the best feature of WireGuard IMO. I'm really looking forward to the mobile clients stabilizing.