Minutes for NETMOD at IETF-88
minutes-88-netmod-1

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NETCONF Data Modeling Language WG (netmod)
IETF #88, Vancouver, Canada
Wednesday, November 6th, 2013, 15:50-17:20, Georgia A
Minutes Alexander Clemm, Juergen Schoenwaelder
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WG Chairs: David Kessens
           Juergen Schoenwaelder
WG URL:    http://tools.ietf.org/wg/netmod/
Jabber:    xmpp:netmod@jabber.ietf.org

Agenda:
          
 1) Administrivia (chairs)                                      [ 5 min]
          
    - minutes scribe     {volunteers welcome in advance!}
    - jabber scribe      {volunteers welcome in advance!}
    - blue sheets
    - agenda bashing
    - status and milestones

 2) Core interface data model (Martin)                          [15 min]

    - draft-ietf-netmod-iana-if-type-07   (WG last call completed?)
    - draft-ietf-netmod-interfaces-cfg-12 (WG last call completed?)
    - draft-ietf-netmod-ip-cfg-11         (WG last call completed)
          
 3) Core routing data model (Martin, Ladislav)                  [15 min]

    - draft-ietf-netmod-iana-afn-safi-00  (ready for WG last call?)
    - draft-ietf-netmod-routing-cfg-11    (ready for WG last call?)
          
 4) Core system data model (Andy)                               [ 0 min]

    - draft-ietf-netmod-iana-timezones-00 (WG last call completed)
    - draft-ietf-netmod-system-mgmt-08    (WG last call completed)

 5) SNMP configuration data model (Martin, Juergen)             [ 5 min]

    - draft-ietf-netmod-snmp-cfg-03       (ready for WG last call?)

 6) Proposals for new infrastructure work                       [25 min]

    - draft-bjorklund-netmod-yang-xpath-extensions-00           [ 5 min]
    - draft-bierman-netmod-yang-conformance-01                  [ 5 min]
    - draft-lhotka-netmod-yang-json-02                          [ 5 min]
    - draft-clemm-netmod-mount-01 (IPR)                         [ 5 min]
    - discussion / prioritization                               [ 5 min]

 7) Proposals for new data models                               [15 min]

    - draft-clemm-netmod-yang-network-topo-01                   [ 5 min]
    - draft-huang-netmod-acl-03                                 [ 5 min]
    - discussion / prioritization                               [ 5 min]

 8) Rechartering discussion                                     [10 min]

 Additional related documents:

  * http://tools.ietf.org/html/draft-yeung-netmod-ospf-00
  * http://tools.ietf.org/html/draft-zhdankin-netmod-bgp-cfg-00
  * http://tools.ietf.org/html/draft-zhou-netmod-openv6-transition-cfg-00

Summary:

  About 60 people attended the NETMOD meeting in Vancouver. The
  chartered documents and the associated actions items are listed
  below:

  - draft-ietf-netmod-ip-cfg has been sent to the AD (Benoit).

  - draft-ietf-netmod-interfaces-cfg and draft-ietf-netmod-iana-if-type
    will both be revised once more to change the interface type to an
    identity. The documents will then be sent to the AD (Benoit).

  - draft-ietf-netmod-routing-cfg will be updated after the IETF meeting
    and then put into WG last call.

  - draft-ietf-netmod-system-mgmt and draft-ietf-netmod-iana-timezones
    have completed WG last call. The shepherd (Juergen) has to produce
    a writeup and then the document will be send to the AD (Benoit).

  - draft-ietf-netmod-snmp-cfg has been updated shortly before the
    meeting and the authors believe it is complete. It will go to WG
    last call.

  The remaining meeting time was used to look at some of the proposed
  new work. The meeting went short of time and further discussions of
  proposed new work and whether the WG should recharter or close down
  once all chartered documents have been delivered will take place on
  the mailing list.

Actors:

  - JS = Juergen Schoenwaelder
  - AB = Andy Bierman
  - MB = Martin Bjorklund
  - LL = Ladislav Lhotka
  - DK = David Kessens
  - BC = Benoit Claise
  - KW = Kent Watsen
  - PS = Phil Shafer
  - AC = Alexander Clemm
  - EV = Eric Voit
  - BL = Balazs Lengyel
  - JM = Jan Medved
  - CM = Carl Moberg
  - L? = Lisa ?

Slides:

  http://www.ietf.org/proceedings/88/netmod.html

Audio:

  http://www.ietf.org/audio/ietf88/

Meeting Notes:

* Core interfaces data model

  MB presented a proposal that was also circulated on the mailing list
  to use identities for interface types.

  The people in the room who were involved in the discussions and who
  have read the document think this is a good way forward. Martin will
  post revised documents and then this will be quickly confirmed on
  the mailing list and then the documents will be with BC.

* Core routing data model

  LL reviewed the changes made in the routing model document.

  MB: I proposed to use a name instead of a numeric identifier.
  MB: Can the numbers change during reboots?
  LL: Probably not a good idea to change the identifiers for routing
      instances and system controlled RIBs.
  LL: I think it is acceptable to use names as keys instead of
      numbers.
  PS: Does the system create these routing instances or are they 
      configured?
  LL: The system creates them.
  PS: Are the number fixed or can they change?
  LL: It might be problematic if they change.
  PS: Can I2RS not use the name as well?
  LL: They insist on using numerical identifiers and they want to
      have they identifiers numeric.
  AC: We need to align our I-Ds containing BGP and OSPF data models
      with the core routing data model.

  LL will revise the document and then it will get last called.

* Core system data model

  JS to produce a writeup and to send the document to the AD (Benoit).

* SNMP configuration data model

  MB explains that text has been added discussing co-existence issues
  (stemming from different persistence models of SNMP and NETCONF)
  that implementers should consider.

  This document will go to WG last call and a high threshold will be
  applied to ensure this document gets proper review.

* Proposals for new infrastructure work

  MB presents a proposal for a YANG extension that can be used to
  define XPATH functions to be used in when and must expressions.

  LL: I support this work but I believe this requires to bump the
      YANG version number.
  PS: I believe this should not require a YANG version number change.
  MB: The change affects a YANG compiler that parses XPATH expressions.
  PS: But it does not affect NETCONF server implementations.
  LL: The extension statements have side effects on other YANG statements.
  MB: This is why this document will update RFC 6020.
  AB: This is somewhat a gray area since the XPATH expression remains
      to be a valid XPATH expression.
  AB: We need to think how we extend YANG. The IEEE way of doing a number
      of extensions that are merged at a certain time into the baseline
      may be a good approach.

  AB presents a mechanism to define conformance profiles for YANG data
  models.

  EV: Is the idea to standardize packages?
  AB: Good question, could be both.
  MB: This seems similar to SMIv2 module conformance, not to agent
      capabilities.
  MB: Can I create a package and claim conformance to a module?
  AB: No, you would claim conformance to your own package.
  PS: I see the value of this from the management application point of
      view. If a server supports a certain package, a management 
      application can manage it. 
  AB: No, it is a contract in the middle.
  BC: How does this I-D solve the import by revision problem?
  AB: Because you have flexibility with the min-revision and max-revision
      statements. Details are in the I-D.

  LL provides an update of his YANG to JSON mapping. The mapping is
  already used by RESTCONF.

  AC presented a proposal to mount remote datastores into a NETCONF
  server.
 
  JS: Why do you believe this belongs to NETMOD and not NETCONF?
  AC: The core of the proposal is the YANG module.
  JS: Can you run an edit-config on mounted data and if so how do
      you make it atomic?
  AC: The reading use case is relatively trivial, writing is of
      course more difficult.
  BL: I believe the protocol issues need to be address for this to
      be useful.
  JM: There are a number of operations that do work without special
      protocol work, but of course, edit-config would require some
      transaction support.
  CM: We have to be careful about the semantics in YANG and how they
      apply to distributed datastores.
  JM: The use case is that you have to compile the device model into
      the controller.
  CM: I agree and I am talking from experience.

* Proposals for new data models

  Skipped due to a shortage of time.

* Discussion and announcement

  DK: Do we need a new charter or do we simply close down and declare
      success?
  AB: Data models like topology data models or packet filter data models
      need to go for a WG forming BOF, they should not be done here.
  L?: We need to get more WG people involved in reviewing. People propose
      new work but chartered work is lacking quite a bit behind.

  DK announces that he will step down as a co-chair. People should
  talk to BC if they are interested in becoming a co-chair. DK will
  continue his duties until a new co-chair has been established.