Re: [Pce] RE: Comment on draft-ietf-pce-pcecp-interarea-reqs-00.txt

Hi,

On Jan 13, 2006, at 4:22 AM, LE ROUX Jean-Louis RD-CORE-LAN wrote:

> Hi Zhang
>
> sorry for replying so late...
>
> Please see inline,
>
> De : Zhang Renhai [mailto:zhangrenhai@huawei.com]
> Envoyé : mercredi 28 décembre 2005 08:04
> À : LE ROUX Jean-Louis RD-CORE-LAN
> Cc : pce@ietf.org
> Objet : Comment on draft-ietf-pce-pcecp-interarea-reqs-00.txt
>
> Hi, Jean-Louis
>
>  I have some comment on the draft draft-ietf-pce-pcecp-interarea- 
> reqs-00.txt
>
>  In section 7.11.1, In case of network failure, jittering will be  
> used to avoid
> simultaneous requests sent to one PCE. Could more consideration be  
> given here to
> the preemptment, becouse the jittering timeout is stochastic, some  
> lower request
> may be served before a higher request and the path may be  
> calculated differently.
> which may increase the probability of a preemptment.
>
> JLLR: You raised a good point.
> First of all note that this point is not a protocol requirement,  
> this is a local implementation issue, and the jittering was just  
> given as an example...
> The PCC could apply different jitter to low priority and high  
> priority requests, and could send
> high priority request before low priority one, this is a local PCC  
> decision.
> Also the request prioritization function could be used so that the  
> PCE serves high priority requests first. The way a PCE is going to  
> handle request prioritites is also a local implementation issue.
> Maybe we should remove this sentence to avoid any confusion.
> By the way note that this section is generic and has just been  
> moved to the generic requirement draft.
> So we will have to clarify in the generic draft.
Thanks indeed to remove this section since this is out of scope.

JP.
>
>
>  I have always been thinking a question: if a PCC will not perform  
> the CSPF
> computation, why does it still maintain the TEDB any longer? which  
> may consume
> a lot of memory and CPU of a LSR.This question dost not aid at this  
> draft.
>
> [JLLR] A LSR may be a PCC for some LSPs and a PCE for other LSPs.
> Anyway a LSR that runs ISIS or OSPF for IP routing has to maintain  
> a LSDB. I agree removing TE info would save some memory and CPU but  
> the gain sounds quite low compared to the impact: For any  
> computation, even a simple intra-area CSPF, you would have to ask a  
> PCE, and this may lead to a high PCE stress. You would have a small  
> CPU gain on LSRs at a cost of a huge CPU consumption on PCEs...
>
> In inter-area environment,sometimes, a PCC may wish to get as many  
> paths as possible,
> for all kinds of purpose,so could the PCC send the request to more  
> than one PCEs?
>
> [JLLR] Yes, and this is a procedure local to the PCC, that does not  
> imply specific PCECP procedure.
>
> Thanks for these valuable comments
>
> Regards,
>
> JL
>
>
> Regards,
> Zhang
> _______________________________________________
> Pce mailing list
> Pce@lists.ietf.org
> https://www1.ietf.org/mailman/listinfo/pce