A few comments on aspects I know something of: The people at BBN might disagree with you... :-) But seriously, throughout its life, the ARPANET had 'load-dependent routing', i.e. paths were adjusted not just in response to links going up or down, but depending on load (so that traffic would avoid loaded links). The first attempt at this (basically a Destination-Vector algorithm, i.e. like RIP but with non-static per-hop costs) didn't work too well, for reasons I won't get into unless anyone cares. The replacement, the first Link-State routing algorithm, worked much, much, better; but it still had minor issues damping fixed most of those too). Actually, two; they were double (9-slot, I guess?) backplanes. Actually, ARP was jointly designed by David Plummer and I for use on both TCP/IP and CHAOS (which is why it has that whole multi-protocol thing going); we added the multi-hardware thing because, well, we'd gone half-way to making it totally general by adding multi-protocol support, so why stop there? As soon as it was done it was used on a variety of IP-speaking MIT machines that were connected to a 10MBit Ethernet; I don't recall them all, but one kind was the MIT C Gateway multi-protocol routers. For some definition of 'work'! (Memories of wrapping protocol A inside protocol B, because some intervening router/link didn't support protocol A, only B...) Noel