[LARTC] bandwidth shaping over multiple WAN links

[Stef Coene]

On Saturday 26 July 2003 11:39, madhuri wrote:
> Hi,
>
> We have three WAN links each of capacity 2 Mbps.
>
> There is a one linux box per link which is used for NAT and firewall. So
> I have three linux boxes and three WAN links to talk to the internet.
>
> We want to do bandwidth shaping over these three links. I know
> individually we can do bandwidth shaping for a particular WAN link using
> linux tc tool. I can repeat the same bandwidth shaping commands for
> other two links also. However it would be better if I can treat three
> links as one big WAN pipe and do the bandwidth shaping for all of them
> at one place. Is it possible?
>
> I am just thinking aloud and not sure if that is possible or not.
It also depends if you want to shape download or upload.  If you want to shape 
upload, you have to realize that you can only use 1 link.  For download, you 
can use 3 links but only if you NAT and you have a lot of connections so you 
can load balance the different connections (like http traffic).  An ftp 
download, will only use 1 link.
This all to say that's not so easy to determine what will be the maximum 
bandiwdth a class can get.  And that's one of the parameters you need to 
create a good tc setup.  But you can create a tc setup that can shape the 3 
links in both directions.  Even if this shaping is not perfect, it still 
beter then not shaping at all.

Stef

-- 

stef.coene@docum.org
 "Using Linux as bandwidth manager"
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