Re: [gentoo-server] network load balancing

[Kashani]

On Thu, 22 Jul 2004, Kurt Lieber wrote:

> Hey all --
>
> I'm trying to help a fellow gentoo developer solve a problem he's having.
> He is unable to get decent broadband speed where he lives and, for various
> reasons, needs to get faster upstream transfer speeds than he can
> currently.  One thought was to get multiple slower lines and combine them.
>
> Any network load balancing solutions out there that might help?  I've
> already checked:
>
> http://lartc.org/howto/lartc.rpdb.multiple-links.html
>
> But this won't help as it chooses a single route for each transfer.  He
> needs to find a way to spread traffic across two (or more) links, even for
> a single file transfer (like an ISO).  So, when transferring a single 1GB
> file, he needs a solution that will send packets across each available
> link.
>
> Any ideas/links/suggestions?

	Normally you'd turn on ECMP, equal cost mutltipath under IP:  
Advanced Router, which would allow you use multiple gateways efficiently. 
Unfortunately this does not give you per-packet load balancing. Linux 
creates a route based on src IP and dest IP and then picks a gateway and 
tosses it into cache. Per-packet is bad anyway as you create a number of 
problems with packets arriving out of order and most docs say you'll 
actually lose speed. Per-connection would work, though I don't see a way 
to do that under Linux. Also that doesn't sound like it'll solve your 
problems either since you have one big connection.
	This will likely be expensive, but you might be able to find a
provider who'd be willing to sell 2-4 connections and bind them together
on both sides. Since the head end is directly attached the usual per
packet problems go away, plus it appears as a single connection to the
local network. Problem is that you need more than you average dsl or cable
modem to make this this happen which also drives up the price.

kashani