​

Stewart, authors and all,
One of the nits in the review mentions inconsistent use of "MUST not" in the 
text that defines  what constitutes an E-Tree service.

I have noticed that the same fragment also contains several cases of "may", and 
it is not clear  to me whether it should be replaced by the 2119 "MAY" or not.

After reading this fragment (as quoted in the review) I wonder whether an 
E-Tree service does not require at least one root and at least two leaves. From 
my POV if the second of these conditions is not met, the connectivity 
restrictions become meaningless, and if the first one is not met, the service 
would not pass any traffic at all.

If these observations are correct, it makes sense to state these limitations 
explicitly using 2119 language (MUST include...).

A apologize for inadvertently sending an earlier version of this text in 
response to a wrong message.

My 2c,
Sasha
________________________________
From: Pals <[email protected]> on behalf of Stewart Bryant 
<[email protected]>
Sent: Monday, March 30, 2015 5:06 PM
To: Jiangyuanlong; [email protected]; [email protected]
Cc: [email protected]; [email protected]; 
[email protected]; [email protected]
Subject: Re: [Pals] Shepherd review of draft-ietf-l2vpn-vpls-pe-etree

Yuanlong

The text has the following nits mostly this is just minor editing but
does need to be fixed.

RFC 6136 can be made an informational ref

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


tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt:
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(20): Line is too long: the offending 
characters are '.'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(227): Line is too long: the offending 
characters are '.'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(415): Line is too long: the offending 
characters are ','
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(579): Line is too long: the offending 
characters are 'e'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(582): Line is too long: the offending 
characters are 'N,'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(632): Line is too long: the offending 
characters are 'n'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(635): Line is too long: the offending 
characters are 'e'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(917): Line is too long: the offending 
characters are 'n'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(924): Line is too long: the offending 
characters are '.'
tmp/draft-ietf-l2vpn-vpls-pe-etree-05.txt(1138): Line has weird spacing: '...) 
where  any t...'


  Checking boilerplate required by RFC 5378 and the IETF Trust (see
  http://trustee.ietf.org/license-info):
  ----------------------------------------------------------------------------

     No issues found here.

  Checking nits according to http://www.ietf.org/id-info/1id-guidelines.txt:
  ----------------------------------------------------------------------------

     No issues found here.

  Checking nits according to http://www.ietf.org/id-info/checklist :
  ----------------------------------------------------------------------------

  ** There are 9 instances of too long lines in the document, the longest one
     being 2 characters in excess of 72.


  Miscellaneous warnings:
  ----------------------------------------------------------------------------

  == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD',
     or 'RECOMMENDED' is not an accepted usage according to RFC 2119.  Please
     use uppercase 'NOT' together with RFC 2119 keywords (if that is what you
     mean).

     Found 'MUST not' in this paragraph:

     The Ethernet-Tree (E-Tree) service is defined in Metro Ethernet
     Forum (MEF) Technical Specification MEF 6.1 as a Rooted-Multipoint
     Ethernet Virtual Connection (EVC) service. It is a multipoint Ethernet
     service with special restrictions: the Ethernet frames from a root may be
     received by any other root or leaf, and the frames from a leaf may be
     received by any root, but MUST not be received by a leaf. Further, an
     E-Tree service may include multiple roots and multiple leaves. Although
     Virtual Private Multicast Service (VPMS) [VPMS] or Point-to-Multipoint
     (P2MP) multicast is a somewhat simplified version of this service, in
     fact, there is no exact corresponding terminology in IETF yet.

  -- The document date (February 26, 2015) is 32 days in the past.  Is this
     intentional?


  Checking references for intended status: Proposed Standard
  ----------------------------------------------------------------------------

     (See RFCs 3967 and 4897 for information about using normative references
     to lower-maturity documents in RFCs)

  == Unused Reference: 'MEF4' is defined on line 872, but no explicit
     reference was found in the text
     '[MEF4]    Metro Ethernet Forum, Metro Ethernet Network Architecture...'

  ** Downref: Normative reference to an Informational RFC: RFC 6136


     Summary: 2 errors (**), 0 flaws (~~), 2 warnings (==), 1 comment (--).


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

Looking at this text




614        1) if the root and leaf VLAN ID in the message match the local root
615           and leaf VLAN ID, then continue to 3);

617        2) else {

619               if the bit V is cleared, then {

621                     if the PE is capable of VLAN mapping, then it MUST set
622                     VLAN-Mapping-Mode to TRUE;

624                     else {

626                          A label release message with the error code "E-Tree
627                          VLAN mapping not supported" is sent to the peer PE
628                          and exit the process;

630                          }

632               }

634               if the bit V is set, and the PE is capable of VLAN mapping,
635               then the PE with the minimum IP address MUST set VLAN-Mapping-
636               Mode to TRUE;

638           }

640        3) If the P bit is set, then:

It might be clearer to apply De Morgan:

Which I think makes it


1) if the root not equal local root or leaf VLAN ID not equal to leaf VLAN ID
   in the message match then


                  if the bit V is cleared, then {

                        if the PE is capable of VLAN mapping, then it MUST set
                        VLAN-Mapping-Mode to TRUE;

                        else {

                             A label release message with the error code "E-Tree
                             VLAN mapping not supported" is sent to the peer PE
                             and exit the process;

                             }

                  }

                  if the bit V is set, and the PE is capable of VLAN mapping,
                  then the PE with the minimum IP address MUST set VLAN-Mapping-
                  Mode to TRUE;

              }

2) If the P bit is set, then:


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