[vox] Throttling router?

Bill Kendrick vox@lists.lugod.org
Wed, 18 Feb 2004 01:05:36 -0800


On Tue, Feb 17, 2004 at 10:03:52PM -0800, Mark K. Kim wrote:
> But thanks for pointing out iproute2.  I figured there's a Linux way
> somewhere.  It's just not practical for my setup right now.  Thanks.

Yeah.  I wish consumer routers-in-a-box could do this as well.
SEEMS trivial enough of an idea, when it's explained to me.
But, then I don't know much about networking. ;^)

What I had been told is that if you give ACKs higher priority to go down
the network, lag in interactive things like SSH will be a lot lower.

Seems to be like this, if I understand correctly:

  Normal situation:

    1. Stuff happens on your SSH session (say, you had typed "ls -lR /")
    2. Bits of data come up at you from your remote host
    3. Your side sends ACKs back down saying "I got it, send more!"
    4. Go back to #2

  Someone uploading and killing your SSH situation:

    1. [same]
    1.5. Some hoser is looking at your website, or you're uploading something
    2. [same]
    2.5. The outward transfer is taking up a lot of your outgoing bandwidth
    3. [same] EVENTUALLY happens
    4. Go back to #2


By increasing the priority of step 3 (sending ACKs to the remote host
you're trying to get data FROM) over step 2.5 (sending huge amounts of data
out to wherever it's being sent to), apparently things like SSH will seem
snappier.

Bandwidth will still be lower, obviously, but for something interactive
like SSH, you're PROBABLY not trying to send huge chunks of data
(unless you're copying-and-pasting War and Peace into a VI session ;^) )


I think Dmitriy or Gabe explained this to me... and then laughed at me
for not having a Linux-based router, and therefore not being able to tweak
this. :^(


So yeah, if anyone knows of a consumer router you can pick up at Fry's
or somewhere, I'd like to hear about it to!


For folks interested in the LINUX solution, I think Gabe's talk on March 15th
will actually go into this.

(Heck, maybe I'll even set my P133 up as a router finally to take advantage
of this... ;^) )


-bill!
(rambling... too much caffiene on the way home from SF)