[131903] in North American Network Operators' Group
RE: RINA - scott whaps at the nanog hornets nest :-)
daemon@ATHENA.MIT.EDU (George Bonser)
Sun Nov 7 02:54:45 2010
Date: Sun, 7 Nov 2010 00:54:40 -0700
In-Reply-To: <alpine.DEB.1.10.1011070832100.2639@uplift.swm.pp.se>
From: "George Bonser" <gbonser@seven.com>
To: "Mikael Abrahamsson" <swmike@swm.pp.se>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
>=20
> Oh, come on. Get real. The world TCP speed record is 10GE right now,
> it'll
> go higher as soon as there are higher interface speeds to be had.
You can buy 100G right now. I also believe there are some 40G
available, too.
Also, check this:
http://media.caltech.edu/press_releases/13216
That was in 2008. =20
=20
> I can easily get 100 megabit/s long-distance between two linux boxes
> without tweaking the settings much.
Until you drop a packet. I can get 100 Megabits/sec with UDP without
tweaking it at all. Getting 100Meg/sec San Francisco to London is a
challenge over a typical Internet path (i.e. not a dedicated leased
path).
> Or they might tweak some other TCP settings and get 30 meg/s with
> existing
> 1500 MTU. It's WAY easier to tweak existing TCP than trying to get the
> whole network to go to a higher MTU. We do 4470 internally and on
> peering
> links where the other end agrees, but getting it to work all the way
to
> the end customer isn't really easy.
I guess you didn't read the links earlier. It has nothing to do with
stack tweaks. The moment you lose a single packet, you are toast. And
there is a limit to how much you can buffer because at some point it
becomes difficult to locate a packet to resend. *If* you have a perfect
path, sure, but that is generally not available, particularly to APAC.
> But in a transition some end systems will have 9000 MTU and some parts
> of
> the network will have smaller, so then you get problems.
Which is no different than end systems that have 9000 today. A lot of
networks run jumbo frames internally now. Maybe a lot more than you
realize. When you are using NFS and iSCSI and other things like
database queries that return large output, large MTUs save you a lot of
packets. NFS reads in 8K chunks, that can easily fit in a 9000 byte
packets. It is more common in enterprise and academic networks that you
might be aware.
