I did a rough, top-of-the-head, with ~60 bytes header (ETH, IP, TCP) into 1500 and 4470 (a mistake, on my part, not to use 9216). I still think the cost outweighs the gain, though there are some reasonable arguments for the increase. Gian Anthony Constantine On Apr 12, 2007, at 12:07 PM, Saku Ytti wrote:
On (2007-04-12 16:28 +0200), Iljitsch van Beijnum wrote:
On 12-apr-2007, at 16:04, Gian Constantine wrote:
I agree. The throughput gains are small. You're talking about a difference between a 4% header overhead versus a 1% header overhead (for TCP).
6% including ethernet overhead and assuming the very common TCP timestamp option.
Out of curiosity how is this calculated? [ytti@ytti.fi ~]% echo "1450/(1+7+6+6+2+1500+4+12)*100"|bc -l 94.27828348504551365400 [ytti@ytti.fi ~]% echo "8950/(1+7+6+6+2+9000+4+12)*100"|bc -l 99.02633325957070148200 [ytti@ytti.fi ~]%
I calculated less than 5% from 1500 to 9000, with ethernet and adding TCP timestamp. What did I miss?
Or compared without tcp timestamp and 1500 to 4470. [ytti@ytti.fi ~]% echo "1460/(1+7+6+6+2+1500+4+12)*100"|bc -l 94.92847854356306892000 [ytti@ytti.fi ~]% echo "4410/(1+7+6+6+2+4470+4+12)*100"|bc -l 97.82608695652173913000
Less than 3%.
However, I don't think it's relevant if it's 1% or 10%, bigger benefit would be to give 1500 end-to-end, even with eg. ipsec to the office.
-- ++ytti