[153421] in North American Network Operators' Group
RE: IPv6 day and tunnels
daemon@ATHENA.MIT.EDU (Templin, Fred L)
Tue Jun 5 18:51:40 2012
From: "Templin, Fred L" <Fred.L.Templin@boeing.com>
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Date: Tue, 5 Jun 2012 15:50:58 -0700
In-Reply-To: <4FCE8B00.8010001@necom830.hpcl.titech.ac.jp>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> -----Original Message-----
> From: Masataka Ohta [mailto:mohta@necom830.hpcl.titech.ac.jp]
> Sent: Tuesday, June 05, 2012 3:41 PM
> To: Templin, Fred L
> Cc: nanog@nanog.org
> Subject: Re: IPv6 day and tunnels
>=20
> Templin, Fred L wrote:
>=20
> >> Infinity? You can't carry 65516B in an IPv4 packet.
>=20
> > 2) For tunnels over IPv6, let infinity equal (2^32 - 1)
>=20
> You can't carry a 65516B IPv6 packet in an IPv4 packet.
No, but you can carry a ((2^32 - 1) - X) IPv6 packet in
an IPv6 packet. Just insert a jumbogram extension header.
> >> Instead, see the last two lines in second last slide of:
> >>
> >> http://meetings.apnic.net/__data/assets/file/0018/38214/pathMTU.pd=
f
> >>
> >> It is a common condition.
> >
> > Are you interested in only supporting tinygrams? IMHO,
> > go big or go home!
>=20
> Bigger packets makes it rather circuit switching than packet
> switching. The way to lose.
>=20
> Faster is the way to go.
Why only fast when you can have both big *and* fast? See
Matt's pages on raising the Internet MTU:
http://staff.psc.edu/mathis/MTU/
Time on the wire is what matters, and on a 100Gbps wire
you can push 6MB in 480usec. That seems more like packet
switching latency rather than circuit switching latency.
Fred
fred.l.templin@boeing.com=20
> Masataka Ohta
