You only need to do UDP encapsulation on the client side (and then again, you can easily fallback to the kernel acceleration on supported platforms). On the ser

You only need to do UDP encapsulation on the client side (and then again, you can easily fallback to the kernel acceleration on supported platforms). On the server side, SCTP has a BSD sockets API already, and with some creative ethernet bridging, you can convince the kernel to unencapsulate your SCTP packets (doing this right now in a project for WebRTC, so I know it's possible). This is a one-time investment that can be made open-source and can be done in userspace. Of course, a kernel patch to encapsulate SCTP in UDP shouldn't be that difficult either. There's two sides to networking -- client and server. Your arguments may make sense for the client, but they do not make sense for the server, IMO. > There is only one significant user space implementation (usrsctp) That's right, but there are others (one was posted a while back) independent implementations, and the kernel implementations (BSD, Linux, likely others) are indeed different.