Re: [mpls-linux-general] Better to use nfmark vs tc_index?

[Steven V. d. B. <ste...@in...>]

Hi Olivier, Jim,

On Thu, 2001-11-29 at 17:32, Olivier Dugeon wrote:
> Hi Jim,
> 
<did some cutting here>

> > Now to the matter of tc_index.  It seems that nfmark can be used by a
> > scheduling classifier, but it looks like the classifier for tc_index is
> > better.  So it might be that nfmark (or a MPLS mark) is used to influence
> > LSP and EXP descisions (note that DSCP will still be option) and that
> > tc_index is used to influence scheduling.
> 
> 
> Actually for the TC part, we use mpls_index. My latest patch (not 
> publish yet) use mpls_index when it has been configured in the 
> kernel_config and directly the label in the other case. We can recopy 
> this index into the tc_index. The TC mpls classifier has been written 
> for this purpose. The original way we want code is to use u32 
> classifier. But there is two pb.
> 
> 1/ the label is not accessible by u32 classifier. They only start at the 
> ip header not the shim header.
> 
> 2/ Why classify again the packet (CPU power ....) if it has already been 
> classified with iptable or another process ? The shim header (formely 
> the label and/or the EXP fields of the shim header) can be used as a 
> filter mark.
> 
agree, there is no use in doing the same job twice. I think for TC, the
bottom line is that we want to be flexible on the type of classifier to
use (especially in the ingress): tc_index, fw_mark,...

Cheers,
Steven

 
-- 
--
Steven Van den Berghe
ste...@in...
Workgroup Broadband Communication Networks
Department Information Technology
Ghent University - Belgium
Phone:  +32 (0)9 267 35 86 | Fax  :  +32 (0)9 267 35 99
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