This is nice to think about, and maybe even implemented in specialized environments, but as a drop-in solution to e.g. the sockets API, a great deal of function

This is nice to think about, and maybe even implemented in specialized environments, but as a drop-in solution to e.g. the sockets API, a great deal of functionality is lost. First and foremost, in order to achieve the kind of throughput advertised, the kernel cannot do much of any checks on the data sent from userspace, which means userspace must be totally trusted to have access to the network interface. Van Jacobsen toted a very similar scheme for Linux around 2006, named Net Channels. Googling around the various LWN.net articles on the topic reveals many enlightening comments, e.g. https://lwn.net/Articles/169961/ https://lwn.net/Articles/169961/