>> All of the other *computer* network systems were designed for small 
>> networks. Sheesh...
> 
> Uh, no. Really, not.  X.25.  ATM.  ISDN.  SONET.  They're all world-wide 
> networks-of-networks, just like IP. Indeed, IP runs over top of all 
> these networks once you get outside your own building. (Granted, X.25 is 
> probably not much used any more, but it was basically what IP wound up 
> replacing, and again was the substrate carrier for a lot of IP data 
> before SONET got cheap enough to dedicate a fiber to something as 
> trickling slow as IP traffic.)

Interesting. Because from what I've seen, all the earlier technologies 
allow you to connect together maybe a few dozen nodes, and then stop 
working after you try to scale much beyond that. They all use their own 
perculiar addressing scheme, and there's no way of referring to a node 
that isn't on the local network.

To me, it seems that the major contribution of IP is that it gives you 
an addressing system which is independent of the underlying transport 
technology, and has routable addresses (and definite rules for how to 
use them). I haven't seen anything else that does that.

Oh, and then people whine that it doesn't map cleanly to the ISO/OSI 
7-layer model. Oh well...

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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