On Fri, 6 Mar 2015, Kartik Agaram wrote:

> 3. Has there been discussion of solving bufferbloat at the TCP layer, by
> making buffers harder to fill up? I'm thinking of heuristics like
> disallowing a single site from using 80% of the buffer, thereby leaving
> some slack available for other bursty requirements.

There are already multiple solutions at the TCP layer.

1. TCP slows down if it gets ECN responses, so it won't fill up buffers

   not everything implements ECN and some firewall-type devices strip out or lie 
about ECN data

2. TCP slows down if packets get dropped. Not all dropping needs to wait until 
the buffers are full.

2a fq_codel does exactly this, it drops packets when there is congestion, before 
the buffers fill up.

The problem is just getting these changes into new equipment/software and then 
replacing the equipment/software in the field.

David Lang