Looks like they’ve got a mailing list, and a wiki.

]]>So, taking a cue from the “soapbox” messages I used years ago when I wrote the Internet Encyclopedia, I’ve renamed this blog to what it always aspired to be…

]]>Consider, for example, the tree topology. All of the subsets in the routing topology fall into one of two categories: a node and everything above it in the tree (including other branchs reachable from higher nodes), or a node and everything below it in the tree. We can optimize this further (a leaf node and everything ‘above’ it would be the entire tree, so we can collapse all these together), but’s let forget about that for now. We need to address every address in the tree, plus one more bit to tell if we’re grouping up or down.

So, CIDR, requiring an IP address plus 5 or 8 extra bits (depending on if we’re using IPv4 or IPv6 addresses), uses a few more bits than the minimum, but it’s not too bad.

Consider also the modulo-addressed ring. For each node we have two possible groups – one to its left and one to its right. So, again, we need to address each node, plus one more bit. The modulo addressing scheme, requiring two entire addresses, appears more inefficient, but an extra address isn’t too bad a price to pay.

Now what I’d really like to figure out is, say, the failure topology of a sphere with one or more trees overlaid on top of it – much more like the Internet. How many bits do we need to address it injectively?

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