BGP-Based Auto-Discovery for Layer-1 VPNs
draft-ietf-l1vpn-bgp-auto-discovery-05

[Ballot comment]
Sandy Murphy has asked what happens if the basic security assumption
does not hold.

Given the importance of the basic trust assumption - all the participants
are trustworthy, and trust is transitive - it would also be nice if the
security considerations noted *why* the wg feels this is a reasonable
assumption.  (I assume it is based on the fact that all the peers are
members of the same provider network?)

[Ballot discuss]
I do not understand how the scalability section can say that no node needs to store all information. What about routers between PEs? How would the information be flooded otherwise?

[Ballot comment]
Sandy's SecDir review also identified a number of places that would
benefit from some clarification of the text, and provided editorial
comments that should be taken into acccount.

[Ballot discuss]
Process comment: Sandy Murphy's SecDir review needs a response.

As noted in Sandy Murphy's SecDir review, this document seems to
expand the L1VPN concept significantly beyond the scope of RFC 4847
and draft-ietf-l1vpn-applicability-basic-mode, both of which
explicitly rule out inter-as/inter-provider L1VPNs.  Expanding the
scope of inter-AS/inter-provider VPNs makes the assumption about
transitive trust of all BGP speakers rather dubious.

IANA Last Call comments:

Upon approval of this document, IANA will make the following
reference update in the "Subsequent Address Family Identifiers
(SAFI)" registry located at
http://www.iana.org/assignments/safi-namespace

OLD:

69 Layer-1 VPN auto-discovery information
[draft-ietf-l1vpn-bgp-auto-discovery]

NEW:

69 Layer-1 VPN auto-discovery information
[RFC-ietf-l1vpn-bgp-auto-discovery-04.txt]

Proto-write-up for draft-ietf-l1vpn-ospf-auto-discovery-05

Intended status : Standards Track

Recommend that this I-D is progressed in parallel with three other
I-Ds:
- draft-ietf-l1vpn-applicability-basic-mode
- draft-ietf-l1vpn-basic-mode
- draft-ietf-l1vpn-bgp-auto-discovery

(1.a)  Who is the Document Shepherd for this document?  Has the
      Document Shepherd personally reviewed this version of the
      document and, in particular, does he or she believe this
      version is ready for forwarding to the IESG for publication?

Adrian Farrel is the document shepherd.
He has personally reviewed the I-D and believes it is ready for
forwarding to the IESG for publication.

(1.b)  Has the document had adequate review both from key WG members
      and from key non-WG members?  Does the Document Shepherd have
      any concerns about the depth or breadth of the reviews that
      have been performed?

I-D had good level of discussions in WG at early stages.

The draft was introduced to the OSPF WG and presented at an OSPF WG
meeting as it was being developed. This led to constructive feedback
that was incorporated in the I-D.

WG last call was shared with the OSPF WG and this led to additional
review comments.

(1.c)  Does the Document Shepherd have concerns that the document
      needs more review from a particular or broader perspective,
      e.g., security, operational complexity, someone familiar with
      AAA, internationalization or XML?

No concerns.

(1.d)  Does the Document Shepherd have any specific concerns or
      issues 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.  Has an IPR disclosure related to this document
      been filed?  If so, please include a reference to the
      disclosure and summarize the WG discussion and conclusion on
      this issue.

The document is sound.

(1.e)  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?

There were no problems with consensus for this document.

However, there was strong debate about whether an IGP should be used
for this function or whether it was better to use BGP (see the write-up
for draft-ietf-l1vpn-bgp-auto-discovery). The conclusion of this debate
was that:
- Using OSPF has advantages in the eyes of optical equipment vendors
since they already implement OSPF-TE, but do not have BGP
implementations.
- There are some potential scaling issues for OSPF. This point is now
explicitly stated in the I-D, with the caveat that this OSPF
deployment is limited to within the optical domain and so does not
have wider implications for OSPF in the Internet. An alternate
deployment using multiple instances to reduce the scaling impact is
also presented.

The WG decided that it would be best to have both an OSPF and a BGP
solution proceed at this stage.

(1.f)  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
      entered into the ID Tracker.)

No threats. No discontent.

(1.g)  Has the Document Shepherd personally verified that the
      document satisfies all ID nits?  (See
      http://www.ietf.org/ID-Checklist.html and
      http://tools.ietf.org/tools/idnits/).  Boilerplate checks are
      not enough; this check needs to be thorough.  Has the document
      met all formal review criteria it needs to, such as the MIB
      Doctor, media type and URI type reviews?

All checks made.

(1.h)  Has the document split its references into normative and
      informative?  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
      strategy for their completion?  Are there normative references
      that are downward references, as described in [RFC3967]?  If
      so, list these downward references to support the Area
      Director in the Last Call procedure for them [RFC3967].

References split.
No downrefs.

(1.i)  Has the Document Shepherd verified that the document IANA
      consideration section exists and is consistent with the body
      of the document?  If the document specifies protocol
      extensions, are reservations requested in appropriate IANA
      registries?  Are the IANA registries clearly identified?  If
      the document creates a new registry, does it define the
      proposed initial contents of the registry and an allocation
      procedure for future registrations?  Does it suggest a
      reasonable name for the new registry?  See [RFC2434].  If the
      document describes an Expert Review process has Shepherd
      conferred with the Responsible Area Director so that the IESG
      can appoint the needed Expert during the IESG Evaluation?

This is a Standards Track I-D that makes a request for one new codepoint
from an existing registry. The registry and request are clearly
explained in the IANA Considerations section.

(1.j)  Has the Document Shepherd verified that sections of the
      document that are written in a formal language, such as XML
      code, BNF rules, MIB definitions, etc., validate correctly in
      an automated checker?

No such sections.

(1.k)  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
          Relevant content can frequently be found in the abstract
          and/or introduction of the document.  If not, this may be
          an indication that there are deficiencies in the abstract
          or introduction.

This document defines an Open Shortest Path First (OSPF) based
Layer-1 Virtual Private Network (L1VPN) auto-discovery mechanism.
This mechanism enables provider edge (PE) devices using OSPF to
dynamically learn about existence of each other, and attributes of
configured customer edge (CE) links and their associations with
L1VPNs.  This document builds on L1VPN framework and requirements,
and provides a L1VPN basic mode auto-discovery mechanism.

      Working Group Summary
          Was there anything in WG process that is worth noting?  For
          example, was there controversy about particular points or
          were there decisions where the consensus was particularly
          rough?

See the discussion above wrt the BGP/OSPF choice.

      Document Quality
          Are there existing implementations of the protocol?  Have a
          significant number of vendors indicated their plan to
          implement the specification?  Are there any reviewers that
          merit special mention as having done a thorough review,
          e.g., one that resulted in important changes or a
          conclusion that the document had no substantive issues?  If
          there was a MIB Doctor, Media Type or other expert review,
          what was its course (briefly)?  In the case of a Media Type
          review, on what date was the request posted?

OSPF-TE is widely implemented and deployed for optical networks. This
document makes a very simple extension to that work and so is simple to
add to existing implementations.

Although L1VPNs are not currently deployed, various experiments and
interop demos have been conducted. Most of these have focused on
signaling with manual configuration rather than autodiscovery, but at
least one implementation with OSPF autodiscovery is known of, and this
has been used to show a proof-of-concept.

Note that there is nothing to prevent the development of an identical
set of extensions to ISIS-TE. This has been put to the WG as an option
on several occasions, but there have been no volunteers to write an I-D
and no indication of any intent to implement. This should not be a
surprise as, although there are many implementations of ISIS-TE and a
very few of GMPLS ISIS, there are no known GMPLS ISIS implementations
for optical equipment. Nothing precludes a future development of
suitable ISIS extensions being developed in the future either in the
L1VPN WG or the ISIS WG.

Proto-write-up for draft-ietf-l1vpn-bgp-auto-discovery-04

Intended status : Standards Track

Recommend that this I-D is progressed in parallel with three other
I-Ds:
- draft-ietf-l1vpn-applicability-basic-mode
- draft-ietf-l1vpn-basic-mode
- draft-ietf-l1vpn-ospf-auto-discovery

> (1.a)  Who is the Document Shepherd for this document?  Has the
>        Document Shepherd personally reviewed this version of the
>        document and, in particular, does he or she believe this
>        version is ready for forwarding to the IESG for publication?

Adrian Farrel is the document shepherd.
He has personally reviewed the I-D and believes it is ready for
forwarding to the IESG for publication.

> (1.b)  Has the document had adequate review both from key WG members
>        and from key non-WG members?  Does the Document Shepherd have
>        any concerns about the depth or breadth of the reviews that
>        have been performed?

I-D had good level of discussions in WG at early stages.

The draft was introduced to the IDR WG and presented at an IDR WG
meeting as it was being developed. This led to constructive feedback
that was incorporated in the I-D.

WG last call was shared with the IDR WG although this did not lead to
any additional review comments.

> (1.c)  Does the Document Shepherd have concerns that the document
>        needs more review from a particular or broader perspective,
>        e.g., security, operational complexity, someone familiar with
>        AAA, internationalization or XML?

No concerns.

> (1.d)  Does the Document Shepherd have any specific concerns or
>        issues 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.  Has an IPR disclosure related to this document
>        been filed?  If so, please include a reference to the
>        disclosure and summarize the WG discussion and conclusion on
>        this issue.

The document is sound.

> (1.e)  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?

There were no problems with consensus for this document.

However, there was strong debate about whether BGP should be used for
this function or whether it was better to use an IGP (see the write-up
for draft-ietf-l1vpn-ospf-auto-discovery). The conclusion of this debate
was that:
- BGP has some advantages in edge-to-edge advertisement or routing and
  membership information.
- BGP may be preferred because it does not require overloading an IGP.
- There is wide experience of similar advertisements using BGP in
  L3VPNs.
- Equipment vendors who make only optical equipment have no experience
  of BGP and may prefer to use OSPF which is already part of their
  GMPLS implementation rather than implement an additional protocol.
- Operators of transport networks who have deployed GMPLS already have
  to manage and operate an IGP and might prefer not to introduce BGP
  if they are not familiar with it.

The WG decided that it would be best to have both a BGP and an OSPF
solution proceed at this stage.

> (1.f)  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
>        entered into the ID Tracker.)

No threats. No discontent.

> (1.g)  Has the Document Shepherd personally verified that the
>        document satisfies all ID nits?  (See
>        http://www.ietf.org/ID-Checklist.html and
>        http://tools.ietf.org/tools/idnits/).  Boilerplate checks are
>        not enough; this check needs to be thorough.  Has the document
>        met all formal review criteria it needs to, such as the MIB
>        Doctor, media type and URI type reviews?

All checks made.

> (1.h)  Has the document split its references into normative and
>        informative?  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
>        strategy for their completion?  Are there normative references
>        that are downward references, as described in [RFC3967]?  If
>        so, list these downward references to support the Area
>        Director in the Last Call procedure for them [RFC3967].

References split.
No downrefs.

> (1.i)  Has the Document Shepherd verified that the document IANA
>        consideration section exists and is consistent with the body
>        of the document?  If the document specifies protocol
>        extensions, are reservations requested in appropriate IANA
>        registries?  Are the IANA registries clearly identified?  If
>        the document creates a new registry, does it define the
>        proposed initial contents of the registry and an allocation
>        procedure for future registrations?  Does it suggest a
>        reasonable name for the new registry?  See [RFC2434].  If the
>        document describes an Expert Review process has Shepherd
>        conferred with the Responsible Area Director so that the IESG
>        can appoint the needed Expert during the IESG Evaluation?

This is a Standards Track I-D that makes a request for one new codepoint
from an existing registry. The registry and request are clearly
explained in the IANA Considerations section.

> (1.j)  Has the Document Shepherd verified that sections of the
>        document that are written in a formal language, such as XML
>        code, BNF rules, MIB definitions, etc., validate correctly in
>        an automated checker?

No such sections.

> (1.k)  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
>          Relevant content can frequently be found in the abstract
>          and/or introduction of the document.  If not, this may be
>          an indication that there are deficiencies in the abstract
>          or introduction.

The purpose of this document is to define a BGP-based auto-discovery
mechanism for Layer-1 VPNs (L1VPNs). The auto-discovery mechanism for
L1VPNs allows the provider network devices to dynamically discover
the set of PEs having ports attached to CE members of the same VPN.
That information is necessary for completing the signaling phase of
L1VPN connections. One main objective of a L1VPN auto-discovery
mechanism is to support the "single-end provisioning" model, where
addition of a new port to a given L1VPN would involve configuration
changes only on the PE that has this port and on the CE that is
connected to the PE via this port.

>        Working Group Summary
>          Was there anything in WG process that is worth noting?  For
>          example, was there controversy about particular points or
>          were there decisions where the consensus was particularly
>          rough?

See the discussion above wrt the OSPF/BGP choice.

>        Document Quality
>          Are there existing implementations of the protocol?  Have a
>          significant number of vendors indicated their plan to
>          implement the specification?  Are there any reviewers that
>          merit special mention as having done a thorough review,
>          e.g., one that resulted in important changes or a
>          conclusion that the document had no substantive issues?  If
>          there was a MIB Doctor, Media Type or other expert review,
>          what was its course (briefly)?  In the case of a Media Type
>          review, on what date was the request posted?

BGP is widely implemented and deployed for packet networks and for
L3VPNs. This document makes a very simple extension to that work and so
is simple to add to existing implementations.

Although L1VPNs are not currently deployed, various experiments and
interop demos have been conducted. Most of these have focused on
signaling with manual configuration rather than autodiscovery, but an
implementation with an early version of BGP autodiscovery is known of,
and this has been used to show a proof-of-concept.