Gotcha, thanks again. (Sorry Tiger, hope I didn't take the thread too far off topic, just had one those one question leads to another question leads to another kinda situation.) So the TCP/IP suite as a whole spans both network and transport layers, depending on which specific protocol you're looking at. I think that's what was throwing me. So what alternatives are there to the OSI model?

This is all very helpful. With a MIS degree that included two LAN classes, I feel rather silly not having mastered this yet, but believe it or not we only scratched the surface of this concept in my classes. We went through all the layers and described the protocols, but that was pretty much it, nothing really in-depth. So, not only did I never really get it, but I forgot most of what I did grasp once the exam was over. But, that's what happens in a state where the entire public school system is declared unconstitutional (I kid you not!).

I'm sure I'll have some more questions shortly, but now I'm off to read my next tutorial...