Re: [mpls-linux-general] How do you want to use TC with MPLS?

[Olivier D. <Oli...@rd...>]

Hi Jim,

James R. Leu wrote:

> Hello all,
> 
> I'm working on testing some of the feature I've added recently, and I just
> realized I have no idea how anyone would use them.  So I'm asking all of you
> how do you want to use the features of TC with MPLS?  Are the feature provided
> by iptables more apt for being used with MPLS?
> 
> One way I know people want to use TC and MPLS is with respect to
> DiffServ.   Using the DSCP to determine which LSP (L-LSP) or which EXP/LSP
> (E-LSP) a packet should be sent with, then mapping the LSP or EXP/LSP
> back to a DSCP at egress.  But what about the LSRs?  Don't they need to
> do special queuing?  How does TC accomplish special queing without MPLS?
> How should it work with MPLS?
> 


We intend (and start some advanced test in a couple of week) to use MPLS 
+ TC for providing QoS support under MPLS not only DiffServ. So, we want 
to setup an LSP for a specific flow (using iptable for classification) 
and then affect a certian QoS to this flow (using TC). The next step is 
to manage all the LSP with a per-LSP queuing (using WFQ for example).

I'have allready completed a new version of our iptable+tc patch for LSR 
handle but, not yet tested (I'm waiting for new material to increase our 
test network). The two main improvment of this patch is :

- Modify tc mpls filter to hanlde both mpls_index (when setting 
CONFIG_MPLS_INGRESS_POLICING in the kernel config) and directly the 
packet label (when CONFIG_MPLS_INGRESS_POLICING is not set).

- Compute skbuff->mpls_index value with outgoing label for all incoming 
mpls packet inside an LSR node. (not sure where to put this patch)

With this two improvments, LSR can use TC to provide some per-LSP QoS. 
Iptable is not need because packet are allready labelled.

Starting to this, i thing implement CR-LDP and RSVP-TE with true Bandwidth

allocation is simplier. All the traffic management is handle by the kernel.



> Thanks,
> Jim
> 
> PS Yes Olivier, I'm now starting to catch up with you, soon I'll understand why
> your iptables work is so useful :-)


Thank's


> 


> PPS Please Steven respond and explain how you made your DiffServ stuff work
> 
> 

Olivier
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