The factor of 6 was just in reduction of overhead. Granted in the greater scheme of things the overall 4% is relatively insignificant, but there have been many times when doing multiple 10-100+GB transfers that I would have welcomed a 4% reduction of time spent twiddling thumbs! -----Original Message----- From: Jakob Heitz (jheitz) [mailto:jheitz@cisco.com] Sent: Saturday, March 19, 2016 00:34 To: Tim McKee Cc: Dale W. Carder; nanog@nanog.org Subject: Re: Internet Exchanges supporting jumbo frames? You would hardly notice it. Helium is 4 times as heavy as hydrogen, but only marginally less buoyant. Header overhead: Ethernet=38 IPv4=20 TCP=20 Total=78 Protocol efficiency: 1500: 1500/1578 = 95% 9000: 9000/9078 = 99% That's 4% better for a TCP packet, not 600%. Thanks, Jakob.
On Mar 18, 2016, at 6:45 PM, Tim McKee <tim@baseworx.net> wrote:
I would hazard a guess that reducing the packet header overhead *and* the Ethernet interframe gap time by a factor of 6 could make enough of an improvement to be quite noticeable when dealing with huge dataset transfers.
Tim McKee
-----Original Message----- From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Jakob Heitz (jheitz) Sent: Friday, March 18, 2016 18:21 To: Dale W. Carder Cc: nanog@nanog.org Subject: RE: Internet Exchanges supporting jumbo frames?
Then it's mainly TCP slowstart that you're trying to improve?
Thanks, Jakob.
-----Original Message----- From: Dale W. Carder [mailto:dwcarder@wisc.edu] Sent: Friday, March 18, 2016 3:03 PM To: Jakob Heitz (jheitz) <jheitz@cisco.com> Cc: nanog@nanog.org Subject: Re: Internet Exchanges supporting jumbo frames?
Thus spake Jakob Heitz (jheitz) (jheitz@cisco.com) on Fri, Mar 18, 2016 at 09:29:44PM +0000:
What's driving the desire for larger packets?
In our little corner of the internet, it is to increase the performance of a low number of high-bdp flows which are typically dataset transfers. All of our non-commercial peers support 9k.
Dale
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