[e2e] overlay over TCP

[David P. Reed]

Anyone know of any experiments that have involved overlay networks that 
run over TCP virtual circuits, but which try to avoid some of the 
application-layer problems of reliable in-order delivery?

I'm interested in optimizing any end-to-end goal-function other than 
bulk transfer speed.  (yeah, I know about a lot of the research and 
hacking that uses multiple TCP connections to blast a file from here to 
there).

Ideally, I'm interested in approaches that focus on preserving 
TCP-friendliness (and generally would be seen as cooperative in sharing 
the network resources rather than greedy or dangerous).

Obviously I'm interested because I've begun playing around with such 
ideas.  They might be practically useful in a world where UDP is viewed 
as a "security hole," but TCP is not (I don't agree, but why fight 
stupid people if you don't have to).  Don't want to reinvent the wheel.