Layering dogma get all confused and convoluted when faced with engineering ingenuity. At what layer is ATM in the old Cells in Frames spec? Or PPP when running ppp sessions over TCP? Or <blah> over MPLS frames over PPP (over TCP)? Or....?
PPP is a layer below the one it serves, and a layer above the one it uses. Just like most other protocols. cheers, gja -- Grenville Armitage http://gja.space4me.com
