Subject: [mpls] the phrase meets the ITU-T's protection switching requirements in draft-ietf-mpls-tp-psc-itu

From: Loa Andersson <[email-masked]>
Date: Mon, 02 Dec 2013 10:54:35 +0800

Editors/Authors,

I've been thinking about draft-ietf-mpls-tp-psc-itu. The document says
at several places "meets the ITU-T's protection switching requirements"
so I thought I go look these requirements up.

To my surprise I found that the only mpls-tp requirement document we
actually refer is RFC5654.

I don't think we can have an open ended reference to "ITU-T's
protection switching requirements" if they are not documented.

We could of course find the document that list the "ITU-T's protection
switching requirements" and reference that directly.

However my preference would be to add text to the introduction the
"the ITU-T's protection switching requirements" were incorporated in
RFC5654, and then where you now say "meets the ITU-T's protection
switching requirements" instead point to RFC5654 and the exact
requirement.

/Loa

-- 

Loa Andersson                        email: [email-masked]
Senior MPLS Expert                          [email-masked]
Huawei Technologies (consultant)     phone: +46 739 81 21 64

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From: "Ryoo, Jeong-dong" <[email-masked]>
Date: Tue, 3 Dec 2013 03:09:22 +0000

Loa,

The ITU-T's requirements refer to the requirements shown in the liaison statements from ITU-T
(https://datatracker.ietf.org/liaison/1205 and https://datatracker.ietf.org/liaison/1234/ )

Those liaison statements had been listed as informative references in the initial versions of the previous drafts that were merged into the current draft. During the MPLS-RT review performed for the previous separate drafts in August, an issue with referring to the liaison statements was raised. In order to resolve the issue, the relavant contents in the liaison statements have been moved to Appendix and the references were erased.

I think your point is very valid and the document needs to be clear on what those requirements are.

Best regards,

Jeong-dong

________________________________
From : "Loa Andersson" <[email-masked]>
Sent : 2013-12-02 11:54:53 ( +09:00 )
To : [email-masked] <[email-masked]>
Cc : [email-masked] <[email-masked]>, [email-masked] <[email-masked]>, VIGOUREUX, MARTIN (MARTIN) <[email-masked]>
Subject : the phrase meets the ITU-T's protection switching requirements in draft-ietf-mpls-tp-psc-itu

Editors/Authors,

/Loa

--

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From: Loa Andersson <[email-masked]>
Date: Fri, 06 Dec 2013 15:11:30 +0800

Jeong-dong,

The requirement text in the two liaisons are weak, most of is not
requirements at all.

Do you say that RFC5654 is not complete when it comes to linear
protection switching and it is not possible to map what is specified in
draft-ietf-mpls-tp-psc-itu ot RFC5654.

Or do you say that draft-ietf-mpls-tp-psc-itu have alternative ways of
meeting the same requirements.

If it is the first case, we would need to do an update to RFC5564, I 
hope that such an update is litmited to a simple additions and not 
require changes to 5654.

If it is the latter case, you should proceed to do the mapping to
RFC5654.

/Loa

On 2013-12-03 11:09, Ryoo, Jeong-dong wrote:
> (https://datatracker.ietf.org/liaison/1205 and
> https://datatracker.ietf.org/liaison/1234/ )
> Those liaison statements had been listed as informative references in
> the initial versions of the previous drafts that were merged into the
> current draft. During the MPLS-RT review performed for the
> previous separate drafts in August, an issue with referring to the
> liaison statements was raised. In order to resolve the issue, the
> relavant contents in the liaison statements have been moved to Appendix
> and the references were erased.
> ------------------------------------------------------------------------
> *From : *"Loa Andersson" <[email-masked]>
> *Sent : *2013-12-02 11:54:53 ( +09:00 )
> *To : [email-masked]
> <[email-masked]>
> *Cc : [email-masked] <[email-masked]>, [email-masked]
> <[email-masked]>, VIGOUREUX, MARTIN (MARTIN)
> <[email-masked]>
> *Subject : *the phrase meets the ITU-T's protection switching
> requirements in draft-ietf-mpls-tp-psc-itu
>
>
> Editors/Authors,
>

--

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From: "Ryoo, Jeong-dong" <[email-masked]>
Date: Sun, 8 Dec 2013 02:00:09 +0000

Loa,

I have been thinking about how to answer your question.
This is a difficult question for me.
I would like to have opinions from the other editor and authors.

Best regards,

Jeong-dong

________________________________
From : "Loa Andersson" <[email-masked]>
Sent : 2013-12-06 16:11:42 ( +09:00 )
To : Ryoo, Jeong-dong <[email-masked]>, [email-masked] <[email-masked]>
Cc : [email-masked] <[email-masked]>, [email-masked] <[email-masked]>, VIGOUREUX, MARTIN (MARTIN) <[email-masked]>
Subject : Re: the phrase "meets the ITU-T's protection switching requirements" in draft-ietf-mpls-tp-psc-itu

Jeong-dong,

/Loa

On 2013-12-03 11:09, Ryoo, Jeong-dong wrote:
> *From : *"Loa Andersson"
> *Cc : [email-masked] , [email-masked]
> , VIGOUREUX, MARTIN (MARTIN)
>

--

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From: Yaacov Weingarten <[email-masked]>
Date: Sun, 8 Dec 2013 10:32:15 +0200

Hi,

I just want to support Loa on this issue - the "requirements" from the LS
are not really requirements - but rather some corner cases that highlight
some of the extremes for the requirements that are listed in RFC5654. I
think that you should just state that you are trying to cover all of the
cases included in the MPLS-TP requirements, including those highlighted in
the appendices to the document.

just my 2c,
yaacov

On Sun, Dec 8, 2013 at 4:00 AM, Ryoo, Jeong-dong <[email-masked]> wrote:

>  ------------------------------
> *Sent : *2013-12-06 16:11:42 ( +09:00 )
> *To : *Ryoo, Jeong-dong <[email-masked]>,
> [email-masked] <
> [email-masked]>
> *Cc : [email-masked] <[email-masked]>, [email-masked] <
> [email-masked]>, VIGOUREUX, MARTIN (MARTIN) <
> [email-masked]>
> *Subject : *Re: the phrase "meets the ITU-T's protection switching
> requirements" in draft-ietf-mpls-tp-psc-itu
>
>
>
> Jeong-dong,
>
> _______________________________________________
> mpls mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/mpls
>
>

-- 
Thanx and BR,
yaacov

*Still looking for new opportunity*

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From: Huub van Helvoort <[email-masked]>
Date: Mon, 09 Dec 2013 22:07:41 +0100

Hello Loa,

I have carefully re-read RFC5654 and think that
draft-ietf-mpls-tp-psc-itu meets all requirements.

The RFC is missing the details that determine the difference
between the PSC RFC and this draft-ietf-mpls-tp-psc-itu.

The main difference is the behavior experienced by the
operating staff.

Best regards, Huub.

==================

-- 
*****************************************************************
               请记住，你是独一无二的，就像其他每一个人一样

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From: "Adrian Farrel" <[email-masked]>
Date: Mon, 9 Dec 2013 22:28:34 -0000

Hello all,

I wonder if I can offer some thoughts to unblock this since (I'm sure) we would all rather spend our time working on the technical content of the document.

The current text in draft-ietf-mpls-tp-psc-itu (using the Abstract as an example) says:

>   This set of
>   modified and additional behaviors together with the protocol defined
>   in RFC6378 meets the ITU-T's protection switching requirements.

I wonder what message this is trying to convey, and like Loa, I wonder whether we in the IETF are in a position to say whether or not this document addresses the ITU-T's requirements. Perhaps this is aspirational and can be left to the ITU-T to consider.

Maybe the point of the text is to give motivation for this work. The motivation (hopefully) stands on its own. Sure, it was first discussed in the ITU-T and was brought to the IETF in a combination of liaison statements and individual contributions. But I think we can present this document as addressing some specific additional concerns and clarified requirements.

if that is the case, the Abstract could read something like...

   Linear protection mechanisms for the MPLS Transport Profile (MPLS-TP)
   are described in RFC 6378 to meet the requirements described in RFC
   5654.  

   This document describes alternate mechanisms to perform some of the
   sub-functions of linear protection, and also defines additional 
   mechanisms. The purpose of these alternate and additional mechanisms
   is to provide operator control and experience that more closely 
   models the behavior of linear protection seen in other transport 
   networks.

   This document also introduces capabilities and modes for linear
   protection.  A capability is an individual behavior, and nodes 
   advertise their capabilities as described in this document.  A mode
   is a particular combination of capabilities.  Two modes are defined
   in this document: Protection State Coordination (PSC) mode and 
   Automatic Protection Switching (APS) mode.

   This document describes the behavior of the PSC protocol including
   priority logic and state machine when all the capabilities associated
   with the APS mode are enabled.

   This document updates RFC6378 in that the capability advertisement
   method defined here is an addition to that document.

Just a suggestion.
Tell me to shut up and go away if you like :-)

Adrian

> -----Original Message-----
> From: mpls [mailto:[email-masked]] On Behalf Of Huub van Helvoort
> Sent: 09 December 2013 21:08
> To: Loa Andersson; Ryoo, Jeong-dong; [email-masked]
> Cc: [email-masked]; [email-masked]
> Subject: Re: [mpls] the phrase "meets the ITU-T's protection switching

---

From: Loa Andersson <[email-masked]>
Date: Tue, 10 Dec 2013 11:11:24 +0800

Adrian,

Yes the text is better. As Eric pointed out in an off-line mail it
is too long, the maximum for an Abstract is 20 lines, this is 24.

I would suggest that we move paragraph 3 and 4 to the Introduction.

/Loa

--

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From: Loa Andersson <[email-masked]>
Date: Tue, 10 Dec 2013 11:34:10 +0800

Huub,

Yes, the question was not whether if draft-ietf-mpls-tp-psc-itu
satisfactorily meets the requirements in RFC 5654, I believe we have
a general agreement that this is the case.

The question was whether we have additional "ITU-T requirements" not
captured in RFC 5456, and if so where they were documented.

As the discussion stands now and with the Introduction of RFC 5654
stating:

    Furthermore, for carriers it is important that operation of such
    packet transport networks should preserve the look-and-feel to which
    carriers have become accustomed in deploying their optical transport
    networks, while providing common, multi-layer operations, resiliency,
    control, and multi-technology management.

I believe we are on dry ground if we have an explicit reference to that
section and everywhere where the current document says: "... meets the
ITU-T's protection switching requirements" change that to "... meets
the behavioral requirements indicated in the Introduction of RFC 5654".

/Loa

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