There's no interesting distinction between a "native" transport protocol and a transport protocol running on top of a UDP shim. The UDP header is probably necessary for ECMP.
? Maybe i'm misunderstanding what your trying to say, but there are major differences between an ethernet + IP transport and other transports like fiber channel (or even token ring, atm, etc) which has built into the lowest layers buffer crediting / flow control, retransmission, prioritization, etc. Sure you can build much of that higher in the stack but it requires everything in the network to be playing the same game to assure QoS metrics, and if that's the case you don't really have a normal IP network anymore.
By transport protocol I mean layer 4. FC/TR/ATM/IB are (mostly) layer 2 protocols.
I think the idea is that Falcon assumes the underlying network is semi-crappy and works around that (e.g. Falcon assumes that packets arrive out of order then it puts them back in order).
OSI is an entire networking stack designed by committee that died from disuse [1]. The only thing we now remember of it are the functional layers within the protocol.
For example, people sometimes refer to TCP as a "Layer 4" protocol even though (a) TCP predates the invention of Layer 4 and (b) TCP is a square peg that does not exactly fit into the round hole that is Layer 4.
I wish we could forget the other remnants of OSI like x.509, ASN.1, and LDAP. Those were the things good enough to be used for real systems, and I'd still rather crawl over broken glass than implement any of them.
