Re: FTP benchmark proposal

Andi Kleen (ak@muc.de)
Mon, 28 Jun 1999 14:37:34 +0200


On Mon, Jun 28, 1999 at 10:13:09AM +0100, Malcolm Beattie wrote:
> If Alexey's 2.2 "tc" is anything like Alan's 2.0 "shaper" then I
> thought it did the best and only decent way of shaping: dropping
> packets on the floor so that TCP treats it like congestion. The other
> part of the plan was to use Alexey's new routing stuff to simulate
> lots of separate bandwidth-limited clients on one box. Allocate the
> whole box a good chunk of the 10/8 network, and use
> route-by-source-address to route each one via a separate tc qdisc.
> Then the client side of the benchmark consists of forking a lot, each
> child creates and binds a socket to its own 10.x.y.z address and the
> magic of iproute2+tc will make each one into its own low bandwidth
> connection. There's so much that's tweakable in the new routing engine
> that I'd guess we could simulate plenty of slow clients fairly
> realistically.

There is no standard routing filter to simulate varying latency (as
caused by modems with compression and big buffers) or a realistic packet
drop model (the token bucket filter lets through bursts). So I doubt
it'll be very realistic. A WAN Emulator has very different goals from
a simple bandwidth limiter.

-Andi

-- 
This is like TV. I don't like TV.

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