nanog mailing list archives
Re: 923Mbits/s across the ocean
From: "David G. Andersen" <dga () lcs mit edu>
Date: Sun, 9 Mar 2003 12:59:55 -0500
On Sun, Mar 09, 2003 at 02:25:25PM +0100, Iljitsch van Beijnum quacked:
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.
Which makes it doubly a shame that the adaptive buffer tuning tricks haven't made it into production systems yet. It was a beautiful, simple idea that worked very well for adapting to long fat networks: http://www.acm.org/sigcomm/sigcomm98/tp/abs_26.html -dave -- work: dga () lcs mit edu me: dga () pobox com MIT Laboratory for Computer Science http://www.angio.net/ I do not accept unsolicited commercial email. Do not spam me.
Current thread:
- Re: 923Mbits/s across the ocean, (continued)
- Re: 923Mbits/s across the ocean David G. Andersen (Mar 08)
- Re: 923Mbits/s across the ocean alex (Mar 08)
- Re: 923Mbits/s across the ocean Douglas F. Calvert (Mar 10)
- Re: 923Mbits/s across the ocean David G. Andersen (Mar 08)
- Re: 923Mbits/s across the ocean Iljitsch van Beijnum (Mar 08)
- RE: 923Mbits/s across the ocean Cottrell, Les (Mar 08)
- RE: 923Mbits/s across the ocean alex (Mar 08)
- RE: 923Mbits/s across the ocean E.B. Dreger (Mar 08)
- RE: 923Mbits/s across the ocean Cottrell, Les (Mar 08)
- Re: 923Mbits/s across the ocean Joe St Sauver (Mar 08)
- Re: 923Mbits/s across the ocean Iljitsch van Beijnum (Mar 09)
- Re: 923Mbits/s across the ocean David G. Andersen (Mar 09)
- Re: 923Mbits/s across the ocean Iljitsch van Beijnum (Mar 09)
- RE: 923Mbits/s across the ocean Cottrell, Les (Mar 08)
- RE: 923Mbits/s across the ocean Cottrell, Les (Mar 09)
- Re: 923Mbits/s across the ocean Richard A Steenbergen (Mar 09)
- Re: 923Mbits/s across the ocean Iljitsch van Beijnum (Mar 10)
- Re: 923Mbits/s across the ocean Richard A Steenbergen (Mar 10)
- Re: 923Mbits/s across the ocean Iljitsch van Beijnum (Mar 11)
- Re: 923Mbits/s across the ocean William Allen Simpson (Mar 15)
- Re: 923Mbits/s across the ocean Richard A Steenbergen (Mar 09)
- Re: 923Mbits/s across the ocean Stephen Sprunk (Mar 11)