Re: [Bloat] Jumbo frames and LAN buffers (was: RE: Burst Loss)

["Richard Scheffenegger" <rscheff@gmx.at>]

Hi Fred,

Yes, that's the common topology; However, 802.3x is often used only 
unidirectional and with very limited effect, but not bidirectional. At least 
that's the default settings... (I wonder, if both ends of a link are RX, 
would flow control ever get triggered?)

I know a number of deployments, where globally enabling full flowcontrol (as 
opposed to RX / TX only) lead to fewer packet drops, but also to sometimes 
massively reduces network bandwidth.

This is what I meant when I said you don't want to deploy flow control in a 
multi-tier  network topology because of the congestion tree forming.

Best regards,
   Richard

----- Original Message ----- 
From: "Fred Baker" <fred@cisco.com>
To: "Richard Scheffenegger" <rscheff@gmx.at>
Cc: "Jonathan Morton" <chromatix99@gmail.com>; <bloat@lists.bufferbloat.net>
Sent: Monday, May 16, 2011 11:49 AM
Subject: Re: [Bloat] Jumbo frames and LAN buffers (was: RE: Burst Loss)



On May 16, 2011, at 9:51 AM, Richard Scheffenegger wrote:

> Second, you wouldn't want to deploy basic 802.3x to any network consisting 
> of more than a single switch.

actually, it's pretty common practice. Three layers, even. People build 
backbones, and then ring them with workgroup switches, and then put small 
switches on their desks.=