Re: Egress bandwidth limiting not working?

[Sebastian Arcus <shop@open-t.co.uk>]

On 08/05/13 07:10, Andrew Beverley wrote:
> On Tue, 2013-05-07 at 11:53 +0100, Sebastian Arcus wrote:
>> I am trying to limit the bandwidth used by the egress leg as per the
>> lartc cookbook here:
>> http://www.lartc.org/howto/lartc.cookbook.ultimate-tc.html
>>
>> The ingress works fine (well, it is a bit wobbly - but it limits the
>> rate at roughly the expected level). However, the egress doesn't appear
>> to be working. With no tc active, I get about 300mbs both ways (I'm
>> testing in VMs). When it is on, the ingress is down to roughly 500kbs,
>> but the egress is down to only about *150mbs*.
>
> Have you tried a qdisc other than CBQ, such as HTB? I've never actually
> used CBQ myself, but from the LARTC HOWTO:
>
> "CBQ is the most complex qdisc available, the most hyped, the least
> understood, and probably the trickiest one to get right. This is not
> because the authors are evil or incompetent, far from it, it's just that
> the CBQ algorithm isn't all that precise and doesn't really match the
> way Linux works."
>
> Are you just trying to achieve simple policing of the interface, or
> something more advanced?
>

Thanks Andrew. I'm only trying to achieve bandwidth limitation and QoS 
priority for some VoIP traffic. I did not notice that paragraph above in 
the LARTC HOWTO and I certainly wouldn't want to complicate things 
unnecessarily :-). I'll give HTB a go and report back. The main reason I 
used CBQ is because the Cookbook section of LARTC recommends it in their 
Ultimate Traffic Conditioner chapter. It doesn't mention that CBQ is 
more complex - and the HTB section hints to the need to patch the kernel 
- which put me off at the time.