On Tue, Jun 28, 2005 at 04:52:17PM +0100, Bob wrote:

> I thought the problem was that you needed to limit incoming traffic as 
> well as outgoing traffic.

  i've found that limiting incoming data by queueing on the internal
  "LAN-facing" interface can be very beneficial if configured 
  correctly.

  for instance, RTT to my default gateway is normally 12ms.  the
  highest download bandwidth i can realize is roughly 2650 Kb/s.
  if i am downloading without queueing incoming, pings to the gateway
  under full-tilt download hover at around 500-700ms.

  if i set pf to queue incoming at an altq bandwidth of around 2500 Kb/s,
  i do not find that i lose much in the way of potential download 
  throughput, however under a full-tilt download, the RTT only goes to
  about 180-300.  cutting the altq bandwidth down to about 2400 brings
  that down further, yielding around a 40-60ms RTT.

  in a situation where one is trying to use queueing to achieve a high-
  quality RTT across the circuit to your ISP, queueing on incoming data
  also could be a very important factor.

  naturally, a hidden factor would be whether there is a bandwidth
  shortage leaving the DSLAM/HeadEnd you terminate at, or any other
  bandwidth shortages further up the food-chain as you traverse your
  ISPs network.

( eg - if you are provisioned at 3Mb, but there are only a 2 T1s
  leaving the remote unit, and there are 40 other people on there, 
  it is probably a good idea to be a bit more conservative...  in any
  case, one could run pings to whatever hop on the ISP's network is
  most applicable, graph them (or whatever) and look.  spend a day
  or two without being involved in large data transfers ) 

  jared

- 

[ openbsd 3.7 GENERIC ( jun 25 ) // i386 ]

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