At 08:32 12/05/2004, Gray, Richard wrote:

>Hi all...
>
>Has anyone ever established conclusively whether implementing a client-side
>bandwidth throttle improves service for users on 128k and 256k telecom adsl
>accounts?

Yes it does.

>Currently on the network at my home, if one person is downloading a file,
>the Internet becomes close to unusable for other users on our LAN. Games
>and ssh/telnet sessions lag, HTTP requests timeout, and things just
>generally suck. It's particularly noticeable if someone is P2P software
>such as edonkey, which opens up hundreds of connections.
>
>A few people have suggested to me that it is due to the way Telecom's
>equipment handles traffic above the capped limit of a connection. ie. it
>queues the packets rather than just dropping them as it did in the past.
>
>So... Has anyone experimented with locally throttling a connection, and
>configuring it to drop packets rather than queue them?
>
>I was going to try setting a 240kbps limit on my 256k connection and see how
>that goes. If I don't hear back from anyone, then I guess I'll just give
>it a go and post my results back here.

240Kbit downstream (30KB/sec) is about right for Jetstream Surf, and is
what I've been using too.

It's high enough that you don't lose too much total bandwidth and feel
tempted to disable it all the time, but not so high that things begin to
queue up. Also its extremly helpful to throttle the *upstream* rate as
well, and I found that throttling it to 128Kbit worked just fine. (Didn't
have to set it slightly lower like downstream)

Without throttling the upstream rate, any time you're sending a file, it
will burst up to nearly twice that speed for about half a second then stall
for half a second ad-infinitum. Extremely bursty with a tendancy to stall
sometimes for a couple of seconds. With the upstream throttled to 128Kbit I
notice perfectly smooth uploading with no bursting and stalling behaviour.

With both of these in place I find that my ping times while downloading or
uploading flat out stay down around 200-400ms compared to about 2000ms, and
browsing, whilst slower than not downloading is definately usable, instead
of completely unusable.

At the moment I've only got one client PC so I'm just doing it directly on
the PC, but if you've got several PC's you're either going to have to pass
all the traffic through a linux box set up to do QoS (if you do, using sfq
will help even things out among your different client machines and
applications too) or do it directly in the router.

The CLI for my Speedtouch 510v4 has a QoS section that appears to be able
to throttle incomming and outgoing bandwidth and thus do it within the
router, but so far I've been unable to have any success. Anyone else
experimented with the QoSBook settings in the CLI ?

Regards,
Simon

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