[p2p-hackers] Hard question....

Bob Harris bob.harris.spamcontrol at gmail.com
Sat Apr 1 23:54:43 UTC 2006


David, Matthew and Daniel,

While I agree that TCP flow control is good and all, I worry a bit about
the TCP high-horse and the many newbies who misunderstand it. Without
implicating anyone, it's worth pointing out that TCP is not sacrosanct, it
does not provide immunity from congestion, and it does not guarantee
fair bandwidth sharing at the host level.

I can create hundreds of TCP (or TCP-like) flows in parallel, easily consume
more
than my fair share of bandwidth, and easily create congestion at the routers
by
closing and creating TCP connections (slow start, anyone?). Many p2p apps do
exactly that: open many connections to many other hosts.

In fact, I'm cranky at the moment because some
idiot's p2p download is consuming
all the bandwidth at my current wireless hotspot. Maybe what we need is to
extend the TCP
ideas from the flow level to the host-level (and either embed them deep into
the OS
or enforce them via traffic shaping).

That said,
it's better to use a protocol with built-in congestion control than
without, and

it's better to adopt TCP's flow control than either nothing or something
untested at large.

Bob.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://zgp.org/pipermail/p2p-hackers/attachments/20060401/2c8e93f9/attachment.htm


More information about the P2p-hackers mailing list