Shepherd writeup

Draft Title: PBB-EVPN
Draft Name: draft-ietf-l2vpn-pbb-evpn-09

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, 
Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this 
type of RFC indicated in the title page header?

Standards Track.

This is the proper type of RFC as this is a key EVPN draft - providing enhanced 
scaling by combining PBB and EVPN.  The type of RFC is indicated in the title page 

(2) The IESG approval announcement includes a Document Announcement Write-Up. 
Please provide such a Document Announcement Write-Up. Recent examples can be 
found in the "Action" announcements for approved documents. The approval 
announcement contains the following sections:

Technical Summary:

   This document discusses how Ethernet Provider Backbone Bridging (PBB)
   can be combined with Ethernet VPN (EVPN) in order to reduce the
   number of BGP MAC advertisement routes by aggregating Customer/Client
   MAC (C-MAC) addresses via Provider Backbone MAC address (B-MAC),
   provide client MAC address mobility using C-MAC aggregation, confine
   the scope of C-MAC learning to only active flows, offer per site
   policies and avoid C-MAC address flushing on topology changes. The
   combined solution is referred to as PBB-EVPN.

Working Group Summary:

   This document was an L2VPN Working Group document, and w reviewed
   in the working group through multiple iterations of the draft.

   The document passed WG last call in the L2VPN WG but is being advanced
   as AD Sponsored because that WG has closed.

Document Quality:

   The document is of roughly average length (22 pages).

   It is well structured, but needs to be read in the context of the base EVPN 
   RFC (draft-ietf-l2vpn-evpn-11- should be an RFC soon), and requires
   knowledge of Ethernet bridging (including PBB).  

   The document has been through multiple revisions and is now sufficiently
   stable to progress to RFC, and more importantly to be used as a reference
   for creating interoperable implementations (in fact PBB EVPN has already
   been implemented by multiple vendors with more implementations in


    Document Shepherd: Giles Heron (
    Area Director: Adrian Farrel (

(3) Briefly describe the review of this document that was performed by the Document 
Shepherd. If this version of the document is not ready for publication, please explain 
why the document is being forwarded to the IESG.

  The Document Shepherd did a thorough review of the text of version -07 of the draft,
  leading to the authors issuing version -08 with a large number of fixes.  The 
  Document Shepherd then reviewed version -08 of the draft, following which the 
  authors issued version -09 with more fixes.  The shepherd also did a scan through 
  the mail archives and previous IETF meeting minutes to review debates on the draft.

(4) Does the document Shepherd have any concerns about the depth or breadth of the 
reviews that have been performed?


(5) Do portions of the document need review from a particular or from broader
perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or 
internationalization? If so, describe the review that took place.

  No.  From a security perspective the solution inherits the characteristics of the
  base EVPN draft (draft-ietf-l2vpn-evpn-11)

(6) Describe any specific concerns or issues that the Document Shepherd has with this 
document that the Responsible Area Director and/or the IESG should be aware of? 
For example, perhaps he or she is uncomfortable with certain parts of the document, 
or has concerns whether there really is a need for it. In any event, if the WG has 
discussed those issues and has indicated that it still wishes to advance the document, 
detail those concerns here.

  No specific concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required 
for full conformance with the provisions of BCP 78 and BCP 79 have already been 
filed. If not, explain why?


(8) Has an IPR disclosure been filed that references this document? If so, summarize 
any WG discussion and conclusion regarding the IPR disclosures.

  No IPR has been filed against this draft.  However IPR was previously filed by 
  Juniper, Cisco and Alcatel-Lucent (ID #1751, 1910, 2362 and 2363) against the base 
  EVPN spec (draft-ietf-l2vpn-evpn-11).

(9) How solid is the WG consensus behind this document? Does it represent the 
strong concurrence of a few individuals, with others being silent, or does the WG as a 
whole understand and agree with it?

  The L2VPN WG consensus was previously noted as solid.  17 individuals
  supported the draft during WG LC, with nobody giving a differing opinion. 
  There was much more discussion/debate around the base EVPN draft 
  (draft-ietf-l2vpn-evpn-11)  than around this draft.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If 
so, please summarise the areas of conflict in separate email messages to the 
Responsible Area Director. (It should be in a separate email because this 
questionnaire is publicly available.)


(11) Identify any ID nits the Document Shepherd has found in this document. (See and the Internet-Drafts Checklist). Boilerplate checks 
are not enough; this check needs to be thorough.

  No nits.

(12) Describe how the document meets any required formal review criteria, such as 
the MIB Doctor, media type, and URI type reviews.

  No formal review required.

(13) Have all references within this document been identified as either normative or 

  Yes.  The Document Shepherd checked all this as part of the document review.

(14) Are there normative references to documents that are not ready for advancement 
or are otherwise in an unclear state? If such normative references exist, what is the 
plan for their completion?

  No - there is only one normative reference (to the base EVPN spec - 
  draft-ietf-l2vpn-evpn-11, which is already with the IESG).

(15) Are there downward normative references references (see RFC 3967)? If so, list 
these downward references to support the Area Director in the Last Call procedure.

  No - we would anticipate the base EVPN spec (draft-ietf-l2vpn-evpn-11) will be 
  published before this doc (since it has been with the IESG for over 4 months).

(16) Will publication of this document change the status of any existing RFCs? Are 
those RFCs listed on the title page header, listed in the abstract, and discussed in the 
introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, 
and point to the part of the document where the relationship of this document to the 
other RFCs is discussed. If this information is not in the document, explain why the 
WG considers it unnecessary.

  No - no impact on status of existing RFCs.

(17) Describe the Document Shepherd's review of the IANA considerations section, 
especially with regard to its consistency with the body of the document. Confirm that all 
protocol extensions that the document makes are associated with the appropriate 
reservations in IANA registries. Confirm that any referenced IANA registries have been 
clearly identified. Confirm that newly created IANA registries include a detailed 
specification of the initial contents for the registry, that allocations procedures for future 
registrations are defined, and a reasonable name for the new registry has been 
suggested (see RFC 5226).

  There are no IANA considerations beyond those noted in the base EVPN spec

(18) List any new IANA registries that require Expert Review for future allocations. 
Provide any public guidance that the IESG would find useful in selecting the IANA 
Experts for these new registries.

  No new registries.

(19) Describe reviews and automated checks performed by the Document Shepherd to 
validate sections of the document written in a formal language, such as XML code, 
BNF rules, MIB definitions, etc.

  No sections written in a formal language.