To add some further recollection. The talk wasn't about what the code presently was, it was aspirational: about how the structure could be wholly rearchitectured. The goal was simplicity. In networking, you have protocols which a varied and can be mixed and matched and layered, devices which can be plain or have different and varied off-load capabilities, things like power management and hot-plugging, and yet in all this you want to architect code that is modular and has maximal re-use and yet is also high-performance. This talk predated things like wireguard (which presents as a device implemented in software) and network namespaces but you got the impression that it was feeling out these possibilities without explicitly articulating them.