----- Original Message -----
From: "Owen DeLong" <owen@delong.com>
On Jul 18, 2014, at 11:32 , Jay Ashworth <jra@baylink.com> wrote:
----- Original Message -----
From: "Owen DeLong" <owen@delong.com>
But the part that will really bend your mind is when you realize that there is no such thing as "THE Internet".
"The Internet as "the largest equivalence class in the reflexive, transitive, symmetric closure of the relationship 'can be reached by an IP packet from'" -- Seth Breidbart.
Note that the sentence is incomplete
It actually isn't, no. The quoted segment is, as noted, a *relationship*; ie: a function applied to a domain of IP addresses to produce a range of other IP addresses; it's a *function*, and the closure applies it to produce a result.
and as soon as you put something after "from" that is actually meaningful, you end up with different answers for the left hand side of that statement depending on what you put at the right hand side.
Further, even that definition doesn't define a single cohesive entity and the definition of "can be reached by an IP packet" is highly variable and more subjective than you may realize.
Not really.
What we commonly refer to as "THE Internet" is really many different equivalence classes similar to what is described above, but each of them is made up of a collection of independently owned and operated networks that happen to cooperate on traffic delivery to varying extents and happen to have agreed to a common protocol and participate in some of the same management schemes for things like namespace collision avoidance and address distribution.
Hence "transitive". It's not really an accident that "transit" comes from the same root. "The Internet" for all the purposes we generally use it here is composed of all the machines with publicly routable IP addresses between which you can move packets, regardless of what they're hooked to, or who they pay; that was the point Seth made in a much more mathematical-sounding way in his oft-quoted statement. Cheers, -- jra -- Jay R. Ashworth Baylink jra@baylink.com Designer The Things I Think RFC 2100 Ashworth & Associates http://www.bcp38.info 2000 Land Rover DII St Petersburg FL USA BCP38: Ask For It By Name! +1 727 647 1274