Re: [LARTC] SFQ buckets/extensions

From: Alexander Atanasov <alex@ssi.bg>
To: lartc@vger.kernel.org
Subject: Re: [LARTC] SFQ buckets/extensions
Date: Fri, 07 Jun 2002 08:26:14 +0000	[thread overview]
Message-ID: <marc-lartc-102343845812347@msgid-missing> (raw)
In-Reply-To: <marc-lartc-102329319618482@msgid-missing>

On Thu, 6 Jun 2002, Don Cohen wrote:

> Maybe you think it's just incredibly lucky that these sources are
> both sending at just the same rate that they're being served, but
> that's what tcp is supposed to do.  

	No, i do not think like this. If we think just for TCP connections
we may end up with ideas like changig window size. TCP tunes to send this
way but it also tries to send more each 5 seconds, if it have data.
SFQ classify connections with ports, esfq classify them and just by IP so
we can have flows:
	SRC IP+proto+DST IP+PORT - one flow
	just DST IP - one flow
	another	we can think of - one flow
So i think just about packets of size bytes but without protos which they
carry and TCP with its features to tune becomes a kind of exception.

> 
>  > Measurement in bytes can make this more incorrect since you have enqueued
>  > packets with different lenghts which you can not split a part and dequeue
>  > in bytes (sigh wouldn't it be nice? ), counting queues in packets (exactly
>  > what they have) is better. May be doing it like the cbq with average
>  > packet size can gave us better results.
> No, the errors are accumulated.  It's always within one packet of the
> ideal in terms of what's sent.  The advantage of measuring queue
> length in bytes would be more fairness in dropping, i.e., you should
> drop from a queue with 10 packets each of length 1000 bytes instead of
> a queue with 20 packets each of length 100 bytes.

	I didn't get it ? What do you mean - have different queues 
agains packets sizes ?

> I think the version I sent does give control over queue size and
> number of buckets.  It also gives you something called expire, which
> I think might do the same sort of thing that you wanted from your
> limits.  We've discussed it on this list before so I won't go into it
> again. 

	We need a way to control what happens in a subqueue there
are these for now:
	- Time limits you've implemented
	- Someone asked about (G)RED
	- devik asked about wrr for connections
	- others ?

-- 
have fun,
alex

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