[133867] in North American Network Operators' Group
Re: TCP congestion control and large router buffers
daemon@ATHENA.MIT.EDU (Joel Jaeggli)
Sun Dec 19 14:16:24 2010
Date: Sun, 19 Dec 2010 11:16:12 -0800
From: Joel Jaeggli <joelja@bogus.com>
To: Mikael Abrahamsson <swmike@swm.pp.se>
In-Reply-To: <alpine.DEB.1.10.1012091617370.27193@uplift.swm.pp.se>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 12/9/10 7:20 AM, Mikael Abrahamsson wrote:
> 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.
you're going to see more of it, at a minimum cpe are going to have to be
able to drain a gig-e into a port that may be only 100Mb/s. The QOS
options available in a ~$100 cpe router are adequate for the basic purpose.
d-link dir-825 or 665 are examples of such 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.
the consumer cpe that care seem to be mostly oriented along keeping
gaming and voip from being interfereed with by p2p and file transfers.
