nanog mailing list archives

Re: 923Mbits/s across the ocean


From: Iljitsch van Beijnum <iljitsch () muada com>
Date: Sun, 9 Mar 2003 14:25:25 +0100 (CET)


On Sat, 8 Mar 2003, Joe St Sauver wrote:

you will see that for bulk TCP flows, the median throughput is still only
2.3Mbps. 95th%-ile is only ~9Mbps. That's really not all that great,
throughput wise, IMHO.

Strange. Why is that? RFC 1323 is widely implemented, although not
widely enabled (and for good reason: the timestamp option kills header
compression so it's bad for lower-bandwidth connections). My guess is
that the OS can't afford to throw around MB+ size buffers for every TCP
session so the default buffers (which limit the windows that can be
used) are relatively small and application programmers don't override
the default.


Current thread: