Perhaps so, but there is plenty of precedent and quite a few networks operate in this manner (or something close to it). The real problem from an engineering p

Perhaps so, but there is plenty of precedent and quite a few networks operate in this manner (or something close to it). The real problem from an engineering perspective is that doing such a thing makes it much harder to deploy new devices and applications, since identities must be managed by some authority. Sometimes that is what you want (think of a corporate network where access is limited to provisioned devices) but it is not what we want for the public Internet (which is meant to be as general purpose and open-ended as possible).