TCP congestion control and large router buffers

Thu Dec 9 15:20:10 UTC 2010

On Thu, 9 Dec 2010, Vasil Kolev wrote:

> I wonder why this hasn't made the rounds here. From what I see, a change 
> in this part (e.g. lower buffers in customer routers, or a change (yet 
> another) to the congestion control algorithms) would do miracles for 
> end-user perceived performance and should help in some way with the net 
> neutrality dispute.

I'd say this is common knowledge and has been for a long time.

In the world of CPEs, lowest price and simplicity is what counts, so 
nobody cares about buffer depth and AQM, that's why you get ADSL CPEs with 
200+ ms of upstream FIFO buffer (no AQM) in most devices.

Personally I have MQC configured on my interface which has assured bw for 
small packets and ssh packets, and I also run fair-queue to make tcp 
sessions get a fair share. I don't know any non-cisco devices that does 
this.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se