[HECnet] Multinet DECnet over IP?

I think this topic was up once before, but I can't find it right now, so I figured I'd ask. Do anyone have some idea/documentation on how the Multinet capsulates DECnet traffic over IP. I seem to remember it pretended it was like ethernet, but I'd like to have all the details. The reason is that since my TCP/IP for RSX is now at a stage where the basic functionality is pretty stable and good, I might try something new. Implementing a line that uses IP for transport would be useful, and it would also be useful if it was compatible with the Multinet implementation. I wouldn't mind also doing something compatible with Cisco. Anyone have the details of that one? I could also do a very RSX specific implementation, but that would be less useful, I think. Anyone else feel like hacking on TCP/IP on PDP-11s? I have lots of things that could be nice to have under RSX... ;-) Johnny