On Sat, 10 Apr 2004, sunder wrote:
Yes. I know what a tree is, and I am quite familiar with structure of the Internet. These very pretty pictures certainly look like the Internet I am familiar with, but don't resemble trees.
It is a tree. I'll give you a hint. Think of this:
"God is like an infinite sphere, whose center is everywhere and circumference nowhere." Nicholas of Cusa.
Let me give you a hint: a tree is an acyclic graph. The Internet shown in Eugen's pretty pictures is defined by BGP4 peerings between autonomous systems. It is highly cyclic, because everyone wants it that way. As a network, a tree is a delicate structure: any break in links fragments the network. Network engineers spend a lot of time making sure that their networks, and the Internet, are not trees. Multiple peering and transit relationships make the network robust - and cyclic. -- Jim Dixon jdd@dixons.org tel +44 117 982 0786 mobile +44 797 373 7881 http://jxcl.sourceforge.net Java unit test coverage http://xlattice.sourceforge.net p2p communications infrastructure