Re: [LARTC] Theory test

[Andy Furniss <andy.furniss@dsl.pipex.com>]

Kenneth Kalmer wrote:

> ADSL, 512kbps down and 256kbps up. Parent for the internet traffic is
> set at 500kbps, to make sure it becomes the bottleneck...

I used to use 400 when I had 512 ingress, so I am amazed that works - 
but then you say ingress not the problem.

> I attach an esfq to each child HTB, but as you say it would be less
> relevenat for egress...

Were it ingress I woud say have just one class with esfq for sharing out 
bulk traffic per user.

>>Do you know what type of connection you have eg pppoa/e or bridged ip
>>etc. I assume whatever it is ends up as atm cells?
> 
> Barely, as said above it's 512/256 VPN. Underneath the VPN it runs
> PPPoE, but the service simulates a leased line, static ip's, the
> works...

I bet there are alot of overheads on that - and if you are pushing the 
rate close to limit like you are on ingress I suspect you are going 
overlimits. Even if you test with an upload and find a rate that seems 
OK it will all fall apart when the traffic consists of small packets.

You have real ips aswell - so all your students can become p2p nodes = 
lots of small packets. I would consider using htb's mpu and overhead on 
each rate/ceil mpu with pppoe/atm is going to be 106 bytes - overhead I 
am not sure as it's not normal dsl - if it were you could patch tc/htb 
to do it perfectly. Often your atm level sync rate will be a bit higher 
than the advertised rate. If you can get your kit to tell you what that 
is it will be helpful.

Andy.

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