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 From:  Adam Nellemann <adam at nellemann dot nu>
 To:  procha at volny dot cz
 Cc:  m0n0wall at lists dot m0n0 dot ch
 Subject:  Re: [m0n0wall] Dynamic traffic shaper - how?
 Date:  Tue, 17 Feb 2004 23:56:02 +0100
procha at volny dot cz wrote:

> Hi,
> I'm note sure if I understand everithing wall. I'll get example

I'm afraid I'm not sure if I understand everything you write either, 
so I guess we're even :)


> LAN total 10 users 
> Internet 128 kbit/sec , internet adresses on provider network 2
> mbits/sec. Pipe1 128 kbit Queue 1 - 10 linked to pipe1 priority 2
> for each user
> 
> I thinkt result of this configuration will be guaranted speed
> 128/active users  for each  at the moment .

You don't have to make 10 queues manually, instead you can use the 
"Mask" (in your case with LAN users, use "Source" for an outbound 
queue and "Destination" for an inbound queue), this should cause the 
shaper to make a queue for each LAN host!

I think, however, that what you really want to do, is to mask the 
pipes in this way (possible in addition to the queues being masked). 
If you only make a lot of queues (or use masking to achieve the samme 
effect), that all goes through the same 128Kbit pipe, they will all 
share these 128Kbit!


The general rule (as far as I can tell) is:

- Use pipes to limit bandwidth. (Use one to share bandwidth between 
hosts dynamically. Use several, either manual or masked, to split 
bandwidth statically between hosts)

- Use queues to prioritise bandwidth. (In your case it will probably 
be a good idea to mask the queues in the same way as the pipes, so 
each LAN host will have its own queue, and thus work exactly as if it 
had its own 128Kbit WAN connection.)

Also, make sure to get the masks right, as otherwise you will end up 
with a pipe/queue for each internet host accessed by your LAN hosts, 
probably not exactly what you want, and might very well put a large 
strain on m0n0wall (swapping the masks would the LAN hosts 128Kbit to 
each WAN host it connects to, instead of 128Kbit total. Futhermore 
m0n0wall would have to maintain a pipe/queue for each WAN host 
currently connected to any of your LAN hosts, possibly quite a lot!)

As I mentioned, you will probably want to make all your rules work on 
the WAN interface. There is seldom any reason to shape LAN traffic. An 
exception could be reserving a little LAN bandwidth for WAN traffic, 
preventing one set of LAN hosts from slowing down other hosts using 
the WAN. I would personally do this by making some pipes and queues 
for the LAN, and set these up to share the bandwidth dynamically, but 
if you want to be absolutely sure that LAN traffic never limits WAN 
traffic, you might want to use a static split instead?


> Problem - limeted  servers before provider shaper (email).
> 
> Possible solution:
> 
> 1. set higher pipe speed - you said I wouldn't work
> 
> 2. map ip adresses before shaper to other pipe (but I'm not sure
> If I get all adresses)

I'm unsure what you want here?

If what you need is to prioritise some types of packages (ie. either a 
special kind of traffic, or traffic to a number of special servers), 
the this can be done by making a number of queues (two or three should 
suffice), each with different "Ratios", but going to the same pipe. 
You can then make some rules for the "special" packets (ie. either for 
some protocols, such as POP3 and SMTP, or for the server IPs), that 
uses the pipe with the higher "Ratio", and some rules for everything 
else that use the pipe with lower "Ratio". This should ensure that the 
"special" packets gets a higher priority than any "normal" traffic.

Alternativly, you could make a seperate pipe for this "high priority" 
traffic, and let some rules direct all this traffic through this 
"dedicated" pipe (you should of course ensure that the bandwidth of 
all the pipes together does not exceed you actual bandwidth, for this 
to work.)

The last possibility, which can be used in conjunction with either of 
the above solutions, is to bypass the queues altogether for certain 
kind of traffic, thus ensuring that these don't have to wait for other 
traffic. I guess this should only be done with packets which er either 
small or few in number, as you will otherwise risk backlogging you 
connection and thus effectivly put the shaper out of "control"!

I hope this helps?


Adam.

P.S. To everybody reading this: If you find anything wrong with what I 
write about the shaper, in this or other posts, or if you have 
something further to add, please let me know. I am participating in 
the m0n0wall manual project, and might be the one to write the section 
about the shaper!