[56468] in North American Network Operators' Group
Re: 923Mbits/s across the ocean
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Sun Mar 9 08:25:41 2003
Date: Sun, 9 Mar 2003 14:25:25 +0100 (CET)
From: Iljitsch van Beijnum <iljitsch@muada.com>
To: Joe St Sauver <JOE@OREGON.UOREGON.EDU>
Cc: <nanog@nanog.org>
In-Reply-To: <01KTAAS38KYU8WY6VQ@OREGON.UOREGON.EDU>
Errors-To: owner-nanog-outgoing@merit.edu
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.
