Re: Bufferbloat

[David Young <dyoung%pobox.com@localhost>]

On Fri, Jan 07, 2011 at 08:00:09PM +0000, David Brownlee wrote:
> Very interesting blog article from Jim Gettys (apologies to those who
> have already read it) regarding the size of network buffers breaking
> TCP.
> 
> http://gettys.wordpress.com/2010/12/03/introducing-the-criminal-mastermind-bufferbloat/
> 
> I wonder how many people out there are running RED in ALTQ to
> effectively mitigate this on their DSL links?

I have been fighting bufferbloat at work, see
<http://mail-index.netbsd.org/tech-net/2009/03/19/msg001141.html>.

I'll add to my two hasty conclusions in that email, two more
conclusions:

3. The kernel ought to base its decision to drop or queue a packet based
   on realistic transmission-time estimates for the queue.

4. For bus-mastering NICs, there should not be both a transmission queue
   *and* a transmission ring, but only a transmission ring.

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933