Summary We could not make a video call successfully on Safari older than 14.1.1. The call kept disconnecting for some seconds. We got the following error in Nginx’s log SSL: error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca:SSL alert number 48 Root cause The Safari didn’t trust our TLS certificates (certified by Let’s Encrypt) when establishing a TLS connection into our TURN server. It is a known issue that could be found at Bug 219274 - ICE does not resolve for `turns` relay candidates rooted in LetsEncrypt CA . The issue was just recently fixed (end of 2020), therefore old versions of Safari still meet the issues. Solution In our development environment, we replaced the untrusted certificate with a trusted one. We will warn our customers about this issue in our installation guide. Technical explained WebKit is a browser engine developed by Apple and primarily used in its Safari web browser, as well as all iOS web browsers. The WebRTC of WebKit relied on the upstr
Once I was chatting with my teammates... Me : "I wonder why it is always necessary to refer to this source, that source, has anyone done it, is there any research? While no problem is the same, no situation is the same. Why not use our own brains to create a whole new one? Why do we have to be the insiders to consult the outsiders? Isn't that very paradoxical?" My teammate : "I agree with your point that no two situations will be exactly the same and that there is no one size fits all. But there's one like this, I don't think it's all the problems we're dealing with that only we can meet. So of course, if I can find a source to refer to first, it's still better. Just like when implementing a software feature, not every problem is the same. But I still have to go check to see if I'm the only one I've met? Or if someone has met me, I have to see if their method suits me before I decide to try it, but I don't blindly "they do it, I f