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IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery
draft-ietf-pce-disco-proto-isis-08

Revision differences

Document history

Date Rev. By Action
2017-05-16
08 (System) Changed document authors from "Raymond Zhang, Yuichi Ikejiri" to "Raymond Zhang, Yuichi Ikejiri, Jean-Louis Le Roux, JP Vasseur"
2015-10-14
08 (System) Notify list changed from pce-chairs@ietf.org to (None)
2012-08-22
08 (System) post-migration administrative database adjustment to the No Objection position for David Ward
2012-08-22
08 (System) post-migration administrative database adjustment to the No Objection position for Tim Polk
2008-01-08
08 Amy Vezza State Changes to RFC Published from RFC Ed Queue by Amy Vezza
2008-01-08
08 Amy Vezza [Note]: 'RFC 5089' added by Amy Vezza
2008-01-07
08 (System) RFC published
2007-10-17
08 Amy Vezza State Changes to RFC Ed Queue from Approved-announcement sent by Amy Vezza
2007-10-17
08 (System) IANA Action state changed to RFC-Ed-Ack from Waiting on RFC Editor
2007-10-17
08 (System) IANA Action state changed to Waiting on RFC Editor from In Progress
2007-10-17
08 (System) IANA Action state changed to In Progress from Waiting on Authors
2007-10-16
08 (System) IANA Action state changed to Waiting on Authors from In Progress
2007-10-16
08 (System) IANA Action state changed to In Progress
2007-10-16
08 Amy Vezza IESG state changed to Approved-announcement sent
2007-10-16
08 Amy Vezza IESG has approved the document
2007-10-16
08 Amy Vezza Closed "Approve" ballot
2007-10-15
08 Ross Callon State Changes to Approved-announcement to be sent from IESG Evaluation::AD Followup by Ross Callon
2007-10-15
08 David Ward [Ballot Position Update] Position for David Ward has been changed to No Objection from Discuss by David Ward
2007-10-05
08 (System) Removed from agenda for telechat - 2007-10-04
2007-10-04
08 Amy Vezza State Changes to IESG Evaluation::AD Followup from IESG Evaluation by Amy Vezza
2007-10-04
08 Mark Townsley [Ballot Position Update] New position, No Objection, has been recorded by Mark Townsley
2007-10-04
08 Chris Newman [Ballot Position Update] New position, No Objection, has been recorded by Chris Newman
2007-10-03
08 Jon Peterson [Ballot Position Update] New position, No Objection, has been recorded by Jon Peterson
2007-10-03
08 Lisa Dusseault
[Ballot comment]
I still haven't memorized routing terminology so I exercised the terminology section.  FYI:

- The terminology expansion of IS-IS LSP confused me.  Why …
[Ballot comment]
I still haven't memorized routing terminology so I exercised the terminology section.  FYI:

- The terminology expansion of IS-IS LSP confused me.  Why is LSP "Link State PDU" here and "Label Stitched Path" everywhere else?. 
- I assume PCED is PCE-Domain -- only the latter is expanded in terminology
- TLV not defined or referenced (though I realize it's a very well-known TLA in the field)

Section 3.2
- flooding scope through "L1 area" and "L2 sub-domain" -- should this be part of terminology or an explanation referenced?

Section 4.1
- If two PCE-ADDRESS sub-TLVs appear, " only the first occurrence is processed and any others MUST be ignored".  With this requirement, what use is it to allow two of PCE-ADDRESS?  If one can be IPv6 and one IPv4 but only the first one MUST be processed, then the other one is useless.

thx -- Lisa
2007-10-03
08 Lisa Dusseault [Ballot Position Update] New position, No Objection, has been recorded by Lisa Dusseault
2007-10-03
08 Tim Polk [Ballot Position Update] Position for Tim Polk has been changed to No Objection from Discuss by Tim Polk
2007-10-03
08 Jari Arkko [Ballot Position Update] New position, No Objection, has been recorded by Jari Arkko
2007-10-03
08 Tim Polk
[Ballot comment]
In section 4.2:

Is consistent computation of the PrefL, PrefR, PrefS and PrefY field values important?  If so, are
we depending upon common …
[Ballot comment]
In section 4.2:

Is consistent computation of the PrefL, PrefR, PrefS and PrefY field values important?  If so, are
we depending upon common administration of all PCEs?  Without a more detailed algorithm, it
seems likely a PCC could discover a set of PCEs that used very different algorithms for setting
the preference values.
2007-10-03
08 Tim Polk
[Ballot discuss]
In section 4, The IS-IS PCED Sub-TLV, there are some statements about future migration
that would seem to burn our bridges unnecessarily.

  …
[Ballot discuss]
In section 4, The IS-IS PCED Sub-TLV, there are some statements about future migration
that would seem to burn our bridges unnecessarily.

  No additional sub-TLVs will be added to the PCED TLV in the future.
  If a future application requires the advertisement of additional PCE
  information in IS-IS, this will not be carried in the CAPABILITY TLV.

I was fine with the first sentence - if PCED is deemed insufficient, we should define a new
sub-TLV that contains all the necessary information.  However, the next sentence rules out
defining a new sub-TLV for the CAPABILITY TLV!  This doesn't make sense to me, and it seems
modify RFC 4971, which I did not expect.  Shouldn't the last sentence say "will not be
carried in the PCED TLV"?
2007-10-03
08 Tim Polk [Ballot comment]
2007-10-03
08 Tim Polk [Ballot Position Update] New position, Discuss, has been recorded by Tim Polk
2007-10-03
08 Tim Polk
[Ballot comment]
In section 4, The IS-IS PCED Sub-TLV, there are some curious statements about future migration that would seem to burn our bridges unnecessarily. …
[Ballot comment]
In section 4, The IS-IS PCED Sub-TLV, there are some curious statements about future migration that would seem to burn our bridges unnecessarily.

  No additional sub-TLVs will be added to the PCED TLV in the future.
  If a future application requires the advertisement of additional PCE
  information in IS-IS, this will not be carried in the CAPABILITY TLV.

I was fine with the first sentence - if PCED is deemed insufficient, we should define a new
sub-TLV that contains all the necessary information.  However, the next sentence rules out
defining a new sub-TLV for the CAPABILITY TLV!  This doesn't make sense to me, and it seems
modify RFC 4971, which I did not expect.
2007-10-03
08 Lars Eggert [Ballot Position Update] New position, No Objection, has been recorded by Lars Eggert
2007-10-03
08 Cullen Jennings [Ballot Position Update] New position, No Objection, has been recorded by Cullen Jennings
2007-10-03
08 David Ward
[Ballot discuss]
0) The big issue is the claim that IS-IS can be used as failure detection of the PCE. This isn't possible in the …
[Ballot discuss]
0) The big issue is the claim that IS-IS can be used as failure detection of the PCE. This isn't possible in the current protocol architecture. This could be possible in IS-IS:

" The functionality required to monitor PCE application liveness and
withdraw the advertised information from the relevant IS-IS LSP is outside
the scope of IS-IS. When a failure event for the PCE has been communicated
to IS-IS, it will withdraw advertised information about the PCE. It will
only announce lack of reachability to the PCE if the PCE is in fact
unreachable."

It begs the question of what is used to detect the failure but, that goes into some other spec.




1) This sentence is incomplete:

"When the
  PCE address is no longer reachable, the PCE node has failed, has been

  torn down, or there is no longer IP connectivity to the PCE node."
2007-10-03
08 David Ward [Ballot Position Update] New position, Discuss, has been recorded by David Ward
2007-10-03
08 Magnus Westerlund [Ballot Position Update] New position, No Objection, has been recorded by Magnus Westerlund
2007-10-03
08 Russ Housley [Ballot comment]
2007-10-02
08 Ron Bonica [Ballot Position Update] New position, No Objection, has been recorded by Ron Bonica
2007-10-02
08 Russ Housley [Ballot comment]
One error caught by Vijay Gurbani during Gen-ART Review:

  Section 4.1.5: s/Suggested value =4/Suggested value =5/
2007-10-02
08 Russ Housley [Ballot Position Update] New position, No Objection, has been recorded by Russ Housley
2007-09-25
08 Ross Callon Placed on agenda for telechat - 2007-10-04 by Ross Callon
2007-09-25
08 Ross Callon State Changes to IESG Evaluation from Waiting for Writeup::AD Followup by Ross Callon
2007-09-25
08 Ross Callon [Ballot Position Update] New position, Yes, has been recorded for Ross Callon
2007-09-25
08 Ross Callon Ballot has been issued by Ross Callon
2007-09-25
08 Ross Callon Created "Approve" ballot
2007-09-24
08 (System) Sub state has been changed to AD Follow up from New Id Needed
2007-09-24
08 (System) New version available: draft-ietf-pce-disco-proto-isis-08.txt
2007-09-18
08 Ross Callon State Changes to Waiting for Writeup::Revised ID Needed from Waiting for Writeup by Ross Callon
2007-09-11
07 (System) New version available: draft-ietf-pce-disco-proto-isis-07.txt
2007-06-29
08 Yoshiko Fong
IANA Last Call Comments:

[ no change from the response of the 1st Last Call ]

Upon approval of this document, the IANA will take …
IANA Last Call Comments:

[ no change from the response of the 1st Last Call ]

Upon approval of this document, the IANA will take
the following Actions:

Action 1:

Upon approval of this document, the IANA will make
the following assignments in the "IS-IS TLV Codepoints"
registry located at

http://www.iana.org/assignments/isis-tlv-codepoints

sub-registry "Sub-TLVs for TLV 242"

Value Description References
----- ------------------------------ ----------
[tbd (5)] PCE Discovery sub-TLV [RFC-pce-disco-proto-isis-05]


Action 2:

Upon approval of this document, the IANA will in
the following registry "IS-IS TLV Codepoints" located at

http://www.iana.org/assignments/isis-tlv-codepoints

create a new sub-registry "PCED sub-TLVs"

Allocation policy: IETF Consensus

Initial contents of this sub-registry will be:

Sub-TLV Sub-TLV
Type Name References
----- -------- ----------
1 PCE-ADDRESS [RFC-pce-disco-proto-isis-05]
2 PATH-SCOPE [RFC-pce-disco-proto-isis-05]
3 PCE-DOMAIN [RFC-pce-disco-proto-isis-05]
4 NEIG-PCE-DOMAIN [RFC-pce-disco-proto-isis-05]
5 PCE-CAP-FLAGS [RFC-pce-disco-proto-isis-05]
6 CONGESTION [RFC-pce-disco-proto-isis-05]
7-255 Reserved to IANA [RFC-pce-disco-proto-isis-05]

We understand the above to be the only IANA
Actions for this document.
2007-06-28
06 (System) New version available: draft-ietf-pce-disco-proto-isis-06.txt
2007-06-27
08 (System) State has been changed to Waiting for Writeup from In Last Call by system
2007-06-13
08 Amy Vezza Last call sent
2007-06-13
08 Amy Vezza State Changes to In Last Call from Last Call Requested by Amy Vezza
2007-06-13
08 Ross Callon Last Call was requested by Ross Callon
2007-06-13
08 Ross Callon State Changes to Last Call Requested from Waiting for Writeup by Ross Callon
2007-06-06
08 (System) State has been changed to Waiting for Writeup from In Last Call by system
2007-05-30
08 Yoshiko Fong
IANA Last Call Comments:

Upon approval of this document, the IANA will take
the following Actions:

Action 1:

Upon approval of this document, the IANA …
IANA Last Call Comments:

Upon approval of this document, the IANA will take
the following Actions:

Action 1:

Upon approval of this document, the IANA will make
the following assignments in the "IS-IS TLV Codepoints"
registry located at

http://www.iana.org/assignments/isis-tlv-codepoints
sub-registry "Sub-TLVs for TLV 242"

Value Description References
----- ------------------------------ ----------
[tbd (5)] PCE Discovery sub-TLV [RFC-pce-disco-proto-isis-05]


Action 2:

Upon approval of this document, the IANA will in
the following registry "IS-IS TLV Codepoints"
located at

http://www.iana.org/assignments/isis-tlv-codepoints
create a new sub-registry "PCED sub-TLVs"

Allocation policy: IETF Consensus

Initial contents of this sub-registry will be:

Sub-TLV Sub-TLV
Type Name References
----- -------- ----------
1 PCE-ADDRESS [RFC-pce-disco-proto-isis-05]
2 PATH-SCOPE [RFC-pce-disco-proto-isis-05]
3 PCE-DOMAIN [RFC-pce-disco-proto-isis-05]
4 NEIG-PCE-DOMAIN [RFC-pce-disco-proto-isis-05]
5 PCE-CAP-FLAGS [RFC-pce-disco-proto-isis-05]
6 CONGESTION [RFC-pce-disco-proto-isis-05]
7-255 Reserved to IANA [RFC-pce-disco-proto-isis-05]

We understand the above to be the only IANA
Actions for this document.
2007-05-25
08 Samuel Weiler Request for Last Call review by SECDIR is assigned to Bernard Aboba
2007-05-25
08 Samuel Weiler Request for Last Call review by SECDIR is assigned to Bernard Aboba
2007-05-23
08 Amy Vezza State Changes to In Last Call from Last Call Requested by Amy Vezza
2007-05-22
08 Ross Callon State Changes to Last Call Requested from AD Evaluation by Ross Callon
2007-05-22
08 Ross Callon Last Call was requested by Ross Callon
2007-05-22
08 (System) Ballot writeup text was added
2007-05-22
08 (System) Last call text was added
2007-05-22
08 (System) Ballot approval text was added
2007-05-17
08 Ross Callon State Changes to AD Evaluation from Publication Requested by Ross Callon
2007-05-09
08 Dinara Suleymanova
PROTO Write-up

>(1.a) Who is the Document Shepherd for this document?

Adrian Farrel <adrian@olddog.co.uk>

> Has the Document Shepherd personally reviewed this version …
PROTO Write-up

>(1.a) Who is the Document Shepherd for this document?

Adrian Farrel <adrian@olddog.co.uk>

> 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?

Yes

>(1.b) Has the document had adequate review both from key WG
> members and from key non-WG members?

Yes. Cross-review to IS-IS WG held with significant input
received.

> Does the Document Shepherd have any concerns about the
> depth or breadth of the reviews that have been performed?

No concerns.

>(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.

No concerns.

> 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.

None has been filed.

>(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?

WG agrees.

>(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.

>(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.

Yes.

> Has the document met all formal review criteria it needs
> to, such as the MIB Doctor, media type and URI type
> reviews?

Yes.

>(1.h) Has the document split its references into normative and
> informative?

Yes.

> 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?

There is a normative reference to draft-ietf-isis-caps that
is in the RFC Editor Queue.

As noted above, there is a normative reference to
pce-disco-proto-ospf-05.txt. That document is advancing for
publication at the same time.

> 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].

There are downrefs as common for new IS-IS Standards Track
documents. Those listed are:

[ISO] "Intermediate System to Intermediate System Intra-Domain
Routeing Exchange Protocol for use in Conjunction with the
Protocol for Providing the Connectionless-mode Network
Service (ISO 8473)", ISO DP 10589, February 1990.

[RFC3784] Li, T., Smit, H., "IS-IS extensions for Traffic
Engineering", RFC 3784, June 2004.

[RFC3567] Li, T. and R. Atkinson, "Intermediate System to
Intermediate System (IS-IS) Cryptographic Authentication",
RFC 3567, July 2003.

It is believed that the first of these is commonly referenced as
normative without any issue as it is a stable, external
document.

It is believed that ISIS WG action is under way to promote RFCs
3567 and 3784 to Standards Track.

>(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].

IANA section is correct.

IANA allocation is dependent on the registries created for
draft-ietf-isis-caps that is in the RFC Editor Queue.
Identification of the registries is, therefore, necessarily
slightly ambiguous.

Note that the IANA registries are, in part, common with
pce-disco-proto-ospf-05.txt. That document is advancing for
publication at the same time.

> 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?

None required.

>(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?

Not applicable.

>(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

There are various circumstances where it is highly desirable for a
Path Computation Client (PCC) to be able to dynamically and
automatically discover a set of Path Computation Elements (PCE),
along with some information that can be used for PCE selection. When
the PCE is a Label Switching Router (LSR) participating in the
Interior Gateway Protocol (IGP), or even a server participating
passively in the IGP, a simple and efficient way to discover PCEs
consists of using IGP flooding. For that purpose this document
defines extensions to the Intermediate System to Intermediate System
(IS-IS) routing protocol for the advertisement of PCE Discovery
information within an IS-IS area or within the entire IS-IS routing
domain.

> Working Group Summary

The Working Group had consensus on this document.

> Document Quality

It is currently unclear whether these protocol extensions have been
implemented. Note, however, that the protocol procedures are
identical to those in draft-ietf-pce-disco-proto-ospf-05.txt that have
been implemented.

> Personnel
>
> Who is the Document Shepherd for this document?

Adrian Farrel <adrian@olddog.co.uk>

> Who is the Responsible Area Director(s)?

Ross Callon, David Ward.

> Is an IANA expert needed?

No.
2007-05-09
08 Dinara Suleymanova Draft Added by Dinara Suleymanova in state Publication Requested
2007-05-08
05 (System) New version available: draft-ietf-pce-disco-proto-isis-05.txt
2007-05-03
04 (System) New version available: draft-ietf-pce-disco-proto-isis-04.txt
2007-04-09
03 (System) New version available: draft-ietf-pce-disco-proto-isis-03.txt
2007-02-13
02 (System) New version available: draft-ietf-pce-disco-proto-isis-02.txt
2006-12-12
01 (System) New version available: draft-ietf-pce-disco-proto-isis-01.txt
2006-09-20
00 (System) New version available: draft-ietf-pce-disco-proto-isis-00.txt