Re: [mpls] AD review of Soft Preemtion work

[JP Vasseur <[e-mail]>]

Hi Lou,

On Jul 27, 2009, at 2:23 PM, Lou Berger wrote:

> JP,
>
> Why do you say MPLS only?
>

It does but a fatal error in the packet case is quite different than  
in the non packet case. That said, the signaling of a fatal error is  
unchanged.

> It seems to me that this draft could be applied to gmpls as wellll  
> The definition of "fatal error" may be different for gmpls and mpls,

Exactly.

> but as this term isn't defined anywhere there is no issue.
>

Fine with me for sure. Adrian ?

Thanks.

JP.

> Lou
> -----Original Message-----
> From:  JP Vasseur <[e-mail]>
>
> Date: Sun, 26 Jul 2009 22:12:14
> To: Adrian Farrel<[e-mail]>; Lou  
> Berger<[e-mail]>; Deborah Beebe (dbeebe)<[e-mail]>
> Cc: <[e-mail]>; <[e-mail] 
> >; <[e-mail]>; <[e-mail] 
> >; <[e-mail]>; <[e-mail]>
> Subject: Re: AD review of Soft Preemtion work
>
>
> Hi Adrian,
>
> I basically agree with all your comments ...
> Few comments/replies:
> With regards to the path-error ID, it is IMO MPLS focussed, Lou/
> Deborah may want to chime in.
> I definitely agree to insert of reference to 5511. For the other
> changes, I tend to think that they could be addressed with an editor
> note but your call of course.
>
> Thanks.
>
> JP.
>
> On Jul 26, 2009, at 1:32 PM, Adrian Farrel wrote:
>
>> Hi,
>>
>> I've been reading draft-ietf-mpls-3209-patherr-04.txt,
>>
>> prior to kicking off IETF last call.
>>
>> I don't have many questions...
>>
>> The Abstract and Introduction to draft-ietf-mpls-3209-patherr-04.txt
>> explicitly call out MPLS when discussing RSVP-TE PathErr messages.
>> But they do not mention GMPLS. In fact, the only reference to
>> RFC3473 is in section 2.2. I think that the text needs to be clear
>> on whether or not it is intended to apply to GMPLS signaling. This
>> obviously affects how the document is read and applied, and should
>> not be left for people to assume (one way or the other).
>>
>> draft-ietf-mpls-3209-patherr-04.txt uses some BNF (copied from RFC
>> 2205). New "rules" require that any document that uses a formal
>> language includes a reference to the definition of the formal
>> language. Your choice here is:
>> - leave out the text copy from 2205
>> - insert a reference to RFC 5511
>>
>> draft-ietf-mpls-3209-patherr-04.txt Page 4
>> Additionally, PathErr messages may be used in two circumstances:
>> Strike "Additionally,"
>>
>> The RFC Editor will require the first section of draft-ietf-mpls-
>> soft-preemption-17.txt to be the Introduction. I think you can
>> simply re-order the sections you already have, and expand the
>> acronyms in the Introduction section.
>>
>> I am trying to not re-open my mailing list discussions of draft-ietf-
>> mpls-soft-preemption-17.txt from the last couple of years. :-) In
>> section 6.1 you have
>> For each preempted TE LSP, instead of sending an RSVP Path Tear
>> message after the receipt of an RSVP PathErr message notifying a
>> fatal action as documented in [I-D.ietf-mpls-3209-patherr] upon
>> preemption as with hard preemption (which would result in an
>> immediate traffic disruption for the preempted TE LSP), the
>> preempting node's local bandwidth accounting for the preempted TE LSP
>> is zeroed and a PathErr with error code "Reroute" and a error value
>> "Reroute request soft preemption" for that TE LSP is issued upstream
>> toward the head-end LSR.
>> I can't parse this single-sentence paragraph. Can you look at how to
>> break it up? I think the node being described is the preempting
>> node. But the preempting node does not receive a PathErr so the
>> first part of the sentence confuses me.
>>
>> draft-ietf-mpls-soft-preemption-17.txt section 6.1
>> Should a refresh event for a soft preempted TE LSP arrive before the
>> soft preemption timer expires, the soft preempting node MUST continue
>> to refresh the TE LSP.
>> This is the first mention of a soft preemption timer. I think you
>> need to swap the text around so the definition of the timer (2 paras
>> later) is introduced first.
>>
>> draft-ietf-mpls-soft-preemption-17.txt Section 13.2
>> [I-D.ietf-mpls-3209-patherr] should be a Normative reference
>>
>>
>> I have marked the documents as:
>> draft-ietf-mpls-soft-preemption  "AD Evaluation : Revised I-D Needed"
>> draft-ietf-mpls-3209-patherr  "AD Evaluation : Revised I-D Needed"
>> draft-ietf-mpls-gmpls-lsp-reroute  "AD Evaluation : External Party"
>>
>> I'm willing to discuss:
>> a. whether these changes are needed
>> b. whether the changes need a respin or an RFC Editor note
>>
>> Cheers,
>> Adrian
>>
>>
>>
>
>