[Bloat] Jumbo frames and LAN buffers

[Kevin Gross]

I would like to try this. Can you suggest specific equipment to look at. Due
to integration and low port count, most of the cheap consumer stuff has
surprisingly good layer-2 performance. I've tested a bunch of Linksys and
other small/medium business 5 to 24 port gigabit switches. Since I measure
latency, I expect I would have noticed if flow control were kicking in.

Kevin Gross

-----Original Message-----
From: bloat-bounces at lists.bufferbloat.net
[mailto:bloat-bounces at lists.bufferbloat.net] On Behalf Of Jim Gettys
Sent: Monday, May 16, 2011 7:23 AM
To: bloat at lists.bufferbloat.net
Subject: Re: [Bloat] Jumbo frames and LAN buffers

On 05/16/2011 09:15 AM, Kevin Gross wrote:
> All the stand-alone switches I've looked at recently either do not support
> 802.3x or support it in the (desireable) manner described in the last
> paragraph of the linked blog post. I don't believe Ethernet flow control
is
> a factor in current LANs. I'd be interested to know the specifics if
anyone
> sees it differently.

Heh.  Plug wireshark into current off the shelf cheap consumer switches 
intended for the home.  You won't like what you see.  And you have no 
way to manage them.  I was quite surprised last fall when doing my home 
experiments to see 802.3 frames; I had been blissfully unaware of its 
existence, and had to go read up on it as a result.

I don't think any of the enterprise switches are so brain damaged.  So i 
suspect it's mostly lurking to cause trouble in home and small office 
environments, exactly where no-one will know what's going on.
                         - Jim