[Systems] [IT] Bandwidth usage on bender

Giovanni Bajo rasky at develer.com
Tue Aug 4 12:02:14 EDT 2009

On 8/4/2009 2:16 PM, Sascha Silbe wrote:
> On Tue, Aug 04, 2009 at 12:39:59PM +0200, Giovanni Bajo wrote:
>>> How about using traffic shaping directly on bender? Or setting TOS so 
>>> the gateways can prioritize better?
>> The problem is on the other side. From Develer's point of view, the 
>> *incoming* traffic saturates our download bandwidth,
> OK, so traffic policing for TCP on bender?
> What about IPv4 traffic, BTW? Would it work for you if we just told 
> whatever application is causing the traffic to prefer IPv4 over IPv6?

We have full traffic shaping over IPv4:

  * for TCP, you can use as much bandiwdth as you want, we will shape it 
in a lower priority class accordingly to our needs , so you simply don't 
have to worry about hours/days/weekdays/vacation whatever. Just go 
ahead, suck as much bandwidth as we allow at any time, and it's fine 
with us.
  * for UDP, every normal use-case (including videoconferencing, SIP, 
etc.) is fine, as long as it doesn't saturate our upstream or 
downstream. Normally, UDP protocols have a fixed bandwidth usage so it's 
not a problem.

Ayiya causes *saturation* of bandwidth through UDP in both upstream and 
downstream. While we could do something for upstream, we *cannot* do 
anything for downstream (AFAIK, *any* network on the world can be put on 
its knees if you flood it to saturation with UDP packets through a 
larger pipe).

So, to move forward, good options are:

1) Stop using IPv6 tunnels, and use something like 128 IPv4 TCP 
forwarded ports we can open to you. And in the near future, we will give 
a public IPv4 to Bender, and you will even be able to use 6to4, if you 
want to.

2) Keep using IPv6 tunnels, but make sure that *all* the traffic onto it 
is limited to ~1Mbit/s (*without* any burst: we can't allow more than 
that in any single moment). This would mean that you need to shape it 
with tc on Bender *and* on all the remote hosts accessing to it.

Let me add that we are really happy to helping the Sugar project as much 
as we can, so I would be extremely happy if we can find a setup that is 
reasonable for our network and works well for you.

Giovanni Bajo
Develer S.r.l.

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