Greg Egan in his fiction "Dark Integers" (story about two universes with two different mathematics communicating by means of proving theorems around of inconsistence in arithmetic) claims that it is possible to build general purpose computer solely on existing internet routers using only its basic functionality of packet switching (and checksum correction, to be precise).
Is this possible, in principle?
Update.
To make the question more precise:
What is an absolutely minimal set(s) of properties the router network must have that it will be possible to build general purpose computer on top of it?