Re: [LARTC] Unshapeable traffic

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

Tomasz Wrona wrote:
> AF> Maybe you could try further seperating the P2P traffic into bulk and
> AF> network udp/syns/acks etc.
> 
> In fact it's done. UDP and ACKs goes extra prio queue.
> Also statistics say that dropped packets are the same size as other
> packets.

Ahh - OK

> 
> 
> AF>  Depends on what type of P2P clients are,to
> AF> some extent what tcp there OS is running and number of connections.
> AF> Maybe PRIO would be better with bulk going to SFQ and small packets
> AF> getting priority.
> 
> 
> AF>  You could also play around with queue lengths and see
> AF> if that helps.
> 
> OK, I will try.

Do you know roughly how many active connections you have?

I think SFQ should be better than HTB default FIFO.

> 
> 
> AF> Does it actually matter anyway - as it's egress you are shaping and I
> AF> assume the 2Mbit extra doesn't really hurt LAN speeds.
> 
> I doesn't play a role for LAN speed but it shouldn't occur anyway. It
> means that something doesn't work as expected. If it happens on
> download all your shaping is useless at all. You have to leave ie.
> spare 2Mbit [30% !!!] from your leased line not to overload it.

Yes shaping from the wrong end is hard anyway and P2P is always worse.

Saying that the version of BIC tcp that kernel.org was running last time 
I looked is really over aggressive - I hope and suspect that Linux BIC 
has been fixed so this will go away in time.

> 
> BTW. I though if it could be caused ie. by hacked TCP stack of some
> hosts or turned off windows_scaling feature of tcp... ?

I think the fact it's on by default in Linux now hurts - It's off by 
default in Windows AFAIK. Are the senders on your LAN using Linux or 
Windows?

Andy.

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