[188392] in North American Network Operators' Group
RE: Internet Exchanges supporting jumbo frames?
daemon@ATHENA.MIT.EDU (Tim McKee)
Sun Mar 20 11:04:25 2016
X-Original-To: nanog@nanog.org
From: Tim McKee <tim@baseworx.net>
To: "Jakob Heitz (jheitz)" <jheitz@cisco.com>
Date: Sat, 19 Mar 2016 21:49:01 +0000
In-Reply-To: <D7B8992A-B4EC-4EBF-8332-A0F87D9B8FE3@cisco.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
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]=20
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=3D38
IPv4=3D20
TCP=3D20
Total=3D78
Protocol efficiency:
1500: 1500/1578 =3D 95%
9000: 9000/9078 =3D 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:
>=20
> 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 impr=
ovement to be quite noticeable when dealing with huge dataset transfers.
>=20
> Tim McKee
>=20
> -----Original Message-----
> From: NANOG [mailto:nanog-bounces@nanog.org] On Behalf Of Jakob Heitz=20
> (jheitz)
> Sent: Friday, March 18, 2016 18:21
> To: Dale W. Carder
> Cc: nanog@nanog.org
> Subject: RE: Internet Exchanges supporting jumbo frames?
>=20
> Then it's mainly TCP slowstart that you're trying to improve?
>=20
> Thanks,
> Jakob.
>=20
>> -----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?
>>=20
>> 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?
>>=20
>> In our little corner of the internet, it is to increase the=20
>> performance of a low number of high-bdp flows which are typically datase=
t transfers.
>> All of our non-commercial peers support 9k.
>>=20
>> Dale
>=20
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