Re: [mpls] [Technical Errata Reported] RFC5960 (2533)

Hello Stweard,

You replied:

> Speaking as an author, my view is that the original text is correct, and
> the correction is not needed.

As an author you are are an expert in this topic.
However, for the less experienced you knowledge, i.e.:

> It's a fundamental of the IP protocol suite (which includes MPLS)
 > that the parser knows what protocol to expect from the previous
 > header or if there is no previous header from an identifier in
 > the lower layer.

may not be that obvious.

So adding this explanation or the text proposed by Ben:

 > If a section layer does not support multiplexing then it has
 > an implicit means of identifying the payload by the interface
 > over which the payload arrived.

would improve the readability of the document.

Regards, Huub.

> On 30/09/2010 01:18, Benjamin Niven-Jenkins wrote:
>> While the intent of reported errata is technically correct I'm
>> somewhat torn between whether I think it should be rejected, or
>> whether I don't care.
>>
>> My thinking is:
>>
>> The errata is technically correct because a corner case does exist
>> where a section layer that doesn't support higher layer protocol
>> multiplexing can still be used to support MPLS-TP in some scenarios.
>>
>> I don't like the proposed replacement text because the original text
>> is placing a requirement on the section layer technology and I think
>> it is reasonable to say "if you want your section layer to work with
>> MPLS-TP it MUST do/support X", however I don't think it's reasonable
>> to say "if you want your section layer to work with MPLS-TP it MAY
>> have to do X" (which is essentially the change the proposed text
>> makes) because it leaves it unclear as to what is actually required
>> from the section layer which practically reduces to section layers
>> having to support X anyway so it becomes a (implicit) MUST in any case.
>>
>> Furthermore the original text only states that a section layer MUST
>> have a means of identifying the type of payload. If a section layer
>> does not support multiplexing then it has an implicit means of
>> identifying the payload by the interface over which the payload
>> arrived and therefore it meets the requirement as stated by the
>> original text.
>>
>> Ben
>>
>>
>> On 29 Sep 2010, at 18:39, RFC Errata System wrote:
>>
>>> The following errata report has been submitted for RFC5960,
>>> "MPLS Transport Profile Data Plane Architecture".
>>>
>>> --------------------------------------
>>> You may review the report below and at:
>>> http://www.rfc-editor.org/errata_search.php?rfc=5960&eid=2533
>>>
>>> --------------------------------------
>>> Type: Technical
>>> Reported by: Italo Busi<italo.busi@alcatel-lucent.com>
>>>
>>> Section: 3.2
>>>
>>> Original Text
>>> -------------
>>> A section MUST provide a means of identifying the type of payload it
>>> carries.
>>>
>>> Corrected Text
>>> --------------
>>> A section MAY be required to provide a mechanism for multiplexing MPLS
>>> with other protocols.
>>>
>>>
>>> Notes
>>> -----
>>> This change is intended to clarify that providing a multiplexing
>>> capability for a section layer is optional.
>>>
>>> See https://datatracker.ietf.org/liaison/916/
>>>
>>> Instructions:
>>> -------------
>>> This errata is currently posted as "Reported". If necessary, please
>>> use "Reply All" to discuss whether it should be verified or
>>> rejected. When a decision is reached, the verifying party (IESG)
>>> can log in to change the status and edit the report, if necessary.
>>>
>>> --------------------------------------
>>> RFC5960 (draft-ietf-mpls-tp-data-plane-04)
>>> --------------------------------------
>>> Title : MPLS Transport Profile Data Plane Architecture
>>> Publication Date : August 2010
>>> Author(s) : D. Frost, Ed., S. Bryant, Ed., M. Bocci, Ed.
>>> Category : PROPOSED STANDARD
>>> Source : Multiprotocol Label Switching
>>> Area : Routing
>>> Stream : IETF
>>> Verifying Party : IESG
>>> _______________________________________________
>>> mpls mailing list
>>> mpls@ietf.org
>>> https://www.ietf.org/mailman/listinfo/mpls
>>
>
>

-- 
================================================================
                   http://www.van-helvoort.eu/
================================================================
Always remember that you are unique...just like everyone else...