[149060] in North American Network Operators' Group
RE: 10GE TOR port buffers (was Re: 10G switch recommendaton)
daemon@ATHENA.MIT.EDU (George Bonser)
Fri Jan 27 17:36:42 2012
From: George Bonser <gbonser@seven.com>
To: Leo Bicknell <bicknell@ufp.org>
Date: Fri, 27 Jan 2012 22:36:10 +0000
In-Reply-To: <20120127215227.GA28688@ussenterprise.ufp.org>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
>=20
> Buffers in most network gear is bad, don't do it.
>=20
+1
I'm amazed at how many will spend money on switches with more buffering but=
won't take steps to ease the congestion. Part of the reason is trying to =
convince non-technical people that packet loss in and of itself doesn't hav=
e to be a bad thing, that it allows applications to adapt to network condit=
ions. They can use tools to see packet loss, that gives them something to =
complain about. They don't know how to interpret jitter or understand what=
impact that has on their applications. They just know that they can run s=
ome placket blaster and see a packet dropped and want that to go away, so w=
e end up in "every packet is precious" mode.
They would rather have a download that starts and stops and starts and stop=
s rather than have one that progresses smoothly from start to finish and tr=
ying to explain to them that performance is "bursty" because nobody wants t=
o allow a packet to be dropped sails right over their heads. =20
They'll accept crappy performance with no packet loss before they will acce=
pt better overall performance with an occasional packet lost.
If an applications is truly intolerant of packet loss, then you need to add=
ress the congestion, not get bigger buffers.
