use tcp over udp? (Re: [p2p-hackers] UDP file transfer link speed identification)

[Adam Back]

Why don't you just use the tcp stack's tcp implementation and tunnel
the IP packets that TCP sends over upd?

(I am not sure why ppl persist in reimplementing TCP... get it too
aggressive or off by one in some area and your p2p app if widely
deployed will make lots of people block your ports if you win heavily
over tcp in bandwidth allocation).

eg on linux I believe you can use tun or tap do this even in user
space.

Not sure how you'd do it on windows, but there ought to be some way to
do it, given non-microsoft firewalls, vpns, ipsec etc.

This is what zks did in their anonymous-IP overlay system.  Also it is
what cebolla does:

	http://www.cypherspace.org/cebolla/

There is source available on that link.

Adam

On Fri, Jul 22, 2005 at 10:20:41AM -0700, Lemon Obrien wrote:
> where can you get code to simulate tcp using udp?
>  
> joel
> 
> Daniel Stutzbach <agthorr at cs.uoregon.edu> wrote:
> On Thu, Jul 21, 2005 at 04:58:52PM -0700, David Barrett wrote:
> > That's interesting that you monitor not only packet loss, but RTT. TCP
> > makes no mention of monitoring latency. However, you're also operating
> > more aggressively than TCP, so perhaps it doesn't need to.
> 
> Measuring latency is critical to TCP's operation. It computes the
> weighted moving average of the RTT as well as the variance of the RTT
> estimates to compute the timeout interval. Otherwise, it wouldn't
> know how long to wait before declaring a packet lost.