Re: [mpls] [RTG-DIR] RtgDir review: draft-ietf-mpls-ipv6-pw-lsp-ping-03.txt

["Bocci, Matthew (Matthew)" <[e-mail]>]

Hi Carlos,

On 24/11/2012 16:20, "Carlos Pignataro (cpignata)" <[e-mail]>
wrote:

>Hi Matthew,
>
>Many thanks for your review! Please find some follow-ups inline.
>
>On Nov 21, 2012, at 11:12 AM, "Bocci, Matthew (Matthew)"
><[e-mail]> wrote:
>
>> Hello,
>> 
>> I have been selected as the Routing Directorate reviewer for this draft.
>> The Routing Directorate seeks to review all routing or routing-related
>> drafts as they pass through IETF last call and IESG review, and
>>sometimes
>> on special request. The purpose of the review is to provide assistance
>>to
>> the Routing ADs. For more information about the Routing Directorate,
>> please see http://www.ietf.org/iesg/directorate/routing.html
>> 
>> Although these comments are primarily for the use of the Routing ADs, it
>> would be helpful if you could consider them along with any other IETF
>>Last
>> Call comments that you receive, and strive to resolve them through
>> discussion or by updating the draft.
>> 
>> Document: draft-ietf-mpls-ipv6-pw-lsp-ping-03.txt
>> Reviewer: Matthew Bocci
>> Review Date: 21st November 2012
>> IETF LC End Date: 9th November 2012
>> Intended Status: Standards Track
>> 
>> Summary:
>> 
>> This document is basically ready for publication, but has a few minor
>> issues that should be considered prior to publication.
>> 
>> Comments:
>> 
>> Generally I found this to be a very well written and readable draft.
>>There
>> are a few minor issues that I have listed below, mainly relating to the
>> use of terminology.
>> 
>> Major Issues:
>> 
>> No major issues found.
>> 
>> Minor Issues:
>> 
>> Title: The title of the draft is "Label Switched Path (LSP) Ping for
>>IPv6
>> Pseudowire FECs". This might be confusing as it suggests that there are
>> special PW FECs for IPv6. In fact, PW FECs are agnostic to the
>>underlying
>> IP version. Therefore, I suggest changing this to something like "Label
>> Switched Path (LSP) Ping for Pseudowire FECs Advertised over IPv6".
>
>This is a really good comment -- I agree completely.
>
>Essentially, we are defining LSP Ping Target FEC Stack sub-TLVs for IPv6
>LDP, which include the LDP PW FECs and the PE addresses -- only the
>latter being of course IP version dependent.
>
>I like the updated title suggestion. We should also update the
>short_title from "IPv6 PW LSP Ping", suggesting "LSP Ping for PWs over
>IPv6" -- but open to further suggestions.
>
>> 
>> Abstract, 1st paragraph: The abstract (and only the abstract) refers to
>>PW
>> LSPs, but this is not common terminology in existing RFCs. It is true
>>that
>> each direction of an MPLS PW is comprised of a unidirectional LSP, but
>>it
>> might be better to try to align more closely with common terminology and
>> call them the LSPs used for each direction of an MPLS PW.
>
>Sure.
>
>> 
>> Abstract, 2nd paragraph: The draft refers to an IPv6 PW. However, this
>> term could be confused with the colloquial term for an IP Layer 2
>> transport PW, which is a specific PW type that can carry IPv4 or IPv6. I
>> suggest replacing this term with 'a PW that is setup and maintained
>>using
>> an IPv6 LDP session.' Likewise, the short version of the draft title in
>> the draft headers could be clarified to something like 'PW LSP Ping for
>> IPv6'.
>
>Ack on both. Agreed.
>
>> 
>> Introduction: there are a few places where the text refers to a 'target
>> LDP session'. It isn't clear if this means the src/dst of the LDP
>>session
>> that an LSP ping echo request message is targeting (hence target is ok)
>>or
>> if it really means the 'targeted LDP session', which is what this type
>>of
>> LDP session is normally referred as. Please clarify.
>
>There is a little bit of potential ambiguity, yes, although frankly it
>could be either. For the case though that there are two PEs back-to-back
>and we'd have a link instead of targeted LDP adjacency, I prefer to only
>refer to "target" and to clear the ambiguity we can just remove "target"
>and leave "LDP Session" (which is what RFC 4447 uses).

Fine with me.

>
>> 
>> Figure 1 and Figure 2 titles. These are not new FEC types for IPv4 and
>> IPv6, but rather new target FEC stack sub-TLVs. I would help readability
>> to modify the titles accordingly.
>> 
>
>Yes, but this is not only in the Figure titles. We could replace all
>occurrences of 'IPv4 "FEC 128" Pseudowire' with say '"FEC 128" Pseudowire
>- IPv4' or similar.

Agreed. I think that should include the names used in the IANA registries.

Regards

Matthew

>
>Thoughts?
>
>Thanks,
>
>-- Carlos.
>
>> 
>> 
>