[95970] in North American Network Operators' Group
Re: Thoughts on increasing MTUs on the internet
daemon@ATHENA.MIT.EDU (Saku Ytti)
Thu Apr 12 12:22:45 2007
Date: Thu, 12 Apr 2007 19:07:29 +0300
From: Saku Ytti <saku+nanog@ytti.fi>
To: NANOG list <nanog@merit.edu>
In-Reply-To: <A8476F5A-C3D0-4B98-B2AD-B3684582582F@muada.com>
Errors-To: owner-nanog@merit.edu
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
