There is a diagram at The Internet Operating System Counter which is at http://www.hzo.cubenet.de/ioscount/. Take the "Unix networking" link. It was published in iX, a German magazine. Mike Received: (from major at localhost) by minnie.cs.adfa.edu.au (8.9.1/8.9.1) id NAA17356 for pups-liszt; Tue, 22 Dec 1998 13:44:57 +1100 (EST)