NETCONF Working Group                                             R. Tao
Internet-Draft                                                     B. Wu
Intended status: Standards Track                                  Huawei
Expires: September 7, 2020                                        P. Liu
                                                                  H. Cai
                                                            China Mobile
                                                           March 6, 2020


               Self-explanation data Node tag capability
            draft-tao-netconf-notif-node-tag-capabilities-01

Abstract

   Before a client application subscribes to updates from a datastore,
   server capabilities related to "Subscription to YANG Datastores" can
   be advertised using YANG Instance Data format.  These server
   capabilities can be documented at implement time or reported at run-
   time.

   This document proposes a YANG module for self-explanation data Node
   tag capability which augments system capabilities model and provide
   additional self-explanation data node attributes associated with node
   selector within per-node capabilities.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 7, 2020.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Self-explanation data Node tag capability . . . . . . . . . .   3
     2.1.  Tree Diagram  . . . . . . . . . . . . . . . . . . . . . .   4
   3.  YANG Module . . . . . . . . . . . . . . . . . . . . . . . . .   5
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
     4.1.  Updates to the IETF XML Registry  . . . . . . . . . . . .   7
     4.2.  Updates to the YANG Module Names Registry . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   8
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   9
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   9
     6.2.  Informative References  . . . . . . . . . . . . . . . . .  10
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

   As described in [I-D.netconf-notification-capabilities], a server
   supporting YANG-Push MAY have a number of capabilities such as

   o  Supported (reporting) periods for periodic subscriptions

   o  Maximum number of objects that can be sent in an update

   o  Supported dampening periods for on-change subscriptions

   o  The set of data nodes for which on-change notification is
      supported;

   Notification capability model defined in [I-D.netconf-notification-
   capabilities] allows a client to discover basic system capability and
   YANG-Push related capabilities both at implementation-time and run-
   time.  Without using notification capability, it might lead to
   unexpected failure or additional message exchange for NETCONF clients
   to discover data models supported by a NETCONF server.





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   When the state of all subscriptions of a particular Subscriber to be
   fetched is huge, filtering queries of operational state on a server
   based on server capabilities can greatly reduce the amount of data to
   be streamed out to the destination.

   However without self-explanation indication or instruction
   information associated with data node conveyed in Notification
   capability model [I-D.netconf-notification-capabilities] or pre-
   configured selection filter in the YANG Push model, it is hard for
   NETCONF clients to automatically select which data objects are of
   interest using machine to machine interface, e.g., identify a set of
   objects which have a common characteristic, collect specific object
   type nodes.

   This document proposes a YANG module for self-explanation data Node
   tag capability which augments System Capabilities model and provide
   additional self-explanation data node tag attributes associated with
   node selector for queries filtering.

1.1.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Self-explanation data Node tag capability

   The YANG module ietf-notification-capabilities defined in [I-
   D.netconf-notification-capabilities] specify the following server
   capabilities related to YANG Push:

   o  A set of capabilities related to the amount of notifications the
      server can send out

   o  Specification of which data nodes support on-change notifications.

   o  Capability values can be specified on server level, datastore
      level or on specific data nodes (and their contained sub-tree) of
      a specific datastore.  Capability values on a smaller, more
      specific part of the server's data always override more generic
      values.

   o  On-change capability is not specified on a server level as
      different datastores usually have different on-change
      capabilities.  On a datastore level on-change capability for
      configuration and state data can be specified separately.



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   These server capabilities can be provided either at implementation
   time or reported at run time.

   This document augments system capabilities model and provide
   additional data node self explaination attributes associated with
   node selector within per-node capabilities:

   o  Specification of which object type nodes, which performance metric
      nodes, which property related nodes they can push to the target
      recipient;

   o  Specification of measurement precision or granularity associated
      with performance metric related data nodes;

   o  Specification of operation type associated with performance metric
      related data nodes;

   o  Specification of service classification information associated
      with data nodes;

   o  Specification of task group information associated with a set of
      data nodes;

   o  Specification of group name of a set of data nodes they can push
      to the target recipient.

   o  Specification of data source type associated with a set of data
      nodes;

   o  Specfication of multi-source aggregation assocaited with a set of
      data nodes;

2.1.  Tree Diagram

   The following tree diagram [RFC8340] provides an overview of the data
   model.















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    module: ietf-self-explanation-capabilities
    augment /sysc:system-capabilities/sysc:datastore-capabilities/ +
          sysc:per-node-capabilities/sys:node-selection/sys:node-selector:
       +--ro self-describing-attributes* [group-id]
           +--ro group-id                string
           +--ro opm-tag                 tags:tag
           +--ro measurement-precision   tags:tag
           +--ro measurement-scale       tags:tag
           +--ro operation-type          tags:tag
           +--ro service-tag*            tags:tag
           +--ro task-tag*               tags:tag
           +--ro data-source-type        tags:tag
           +--ro parent-grouping         tags:tag

3.  YANG Module

<CODE BEGINS> file "ietf-self-explanation-capabilities.yang"
module ietf-self-explanation-capabilities {
  yang-version 1.1;
  namespace urn:ietf:params:xml:ns:yang:ietf-self-explanation-capabilities;
  prefix sec;
  import ietf-system-capabilities  { prefix sysc ; }
  import ietf-data-node-tags {prefix ntags;}
  import ietf-module-tags  { prefix tags; }
  organization
    "IETF NETMOD (Network Modeling) Working Group";
  contact
    "WG Web:   <https://tools.ietf.org/wg/netconf/>
     WG List:  <mailto:netconf@ietf.org>

     Editor:   Ran Tao
               <mailto:taoran20@huawei.com>
               Qin Wu
               <mailto:bill.wu@huawei.com";
  description
    "This module defines an extension to System Capabilities model
     and provides additional self explaination data node tag attributes
     associated with node selector for queries filtering.

     Copyright (c) 2020 IETF Trust and the persons identified as
     authors of the code.  All rights reserved.

     Redistribution and use in source and binary forms, with or
     without modification, is permitted pursuant to, and subject
     to the license terms contained in, the Simplified BSD License
     set forth in Section 4.c of the IETF Trust's Legal Provisions
     Relating to IETF Documents
     (http://trustee.ietf.org/license-info).



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     This version of this YANG module is part of RFC XXXX;
     see the RFC itself for full legal notices.";
    augment "/sysc:system-capabilities/sysc:datastore-capabilities" +
         "/sysc:per-node-capabilities" +
          "/sysc:node-selection/sysc:node-selector" {
     description "Allows per-node capabilities have additional self-explanation attributes";
     list self-describing-attributes {
      key group-id;
      description "self describing attributes for each data node.";
       leaf group-id {
         type string;
         description
          "This group ID is used to identify a set of data nodes
          of the same group which have a common characteristic.";
       }
         leaf opm-tag {
           type tags:tag ;
           description
            "Object, Property and Metric(OPM) Tags associated with
            the data node within YANG module.
            See the IANA 'YANG Data Node Tag Prefixes' registry
            for reserved prefixes and the IANA
            'IETF YANG Data Node Tags' registry for IETF tags.";
       }
         leaf measurement-precision {
           type tags:tag;
           description
             "The numeric expression precision of performance
              metric related data node.";
         }

        leaf measurement-scale {
            type tags:tag;
            description
             "The measurement scale of performance
              metric related data node.";
         }
         leaf operation-type{
          type tags:tag;
          description
           "Statistics operation of performance metric related
           data node.";
         }
         leaf-list service-tag {
          type tags:tag;
          description
           "The node-service-tag can be used to provide a service
           classification information (e.g., tunnel, l3vpn,l2vpn)



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           information associated with YANG data node.";
         }
         leaf-list task-tag {
          type tags:tag;
          description
           "The node-task-tag can be used to provide a task
           classification information (e.g., fault management,
           performance measurement) information associated with
           YANG data node.";
         }
         leaf data-source-type{
          type tags:tag;
          description
           "The data source type can be used to identify different
            data source type(e.g., service flow, resource, policy,
            qos, hardware).";
         }
         leaf parent-grouping{
          type tags:tag;
          description
           "The parent grouping tag can be used to aggregate peformance metric
            from different sources.";
         }
     }
   }
}
<CODE ENDS>

4.  IANA Considerations

4.1.  Updates to the IETF XML Registry

   This document registers a URI in the "IETF XML Registry" [RFC3688].
   Following the format in [RFC3688], the following registration has
   been made:

      URI:
         urn:ietf:params:xml:ns:yang:ietf-self-explanation-capabilities
      Registrant Contact:
         The IESG.
      XML:
         N/A; the requested URI is an XML namespace.

4.2.  Updates to the YANG Module Names Registry

   This document registers one YANG module in the "YANG Module Names"
   registry [RFC6020].  Following the format in [RFC6020], the following
   registration has been made:



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     name:
        ietf-self-explanation-capabilities
     namespace:
        urn:ietf:params:xml:ns:yang:ietf-self-explanation-capabilities
     prefix:
        sec
     reference:
        RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove
        this note.)

5.  Security Considerations

   The YANG module specified in this document defines a schema for data
   that is designed to be accessed via network management protocols such
   as NETCONF [RFC6241] or RESTCONF [RFC8040].  The lowest NETCONF layer
   is the secure transport layer, and the mandatory-to-implement secure
   transport is Secure Shell (SSH) [RFC6242].  The lowest RESTCONF layer
   is HTTPS, and the mandatory-to-implement secure transport is TLS
   [RFC8446].

   The NETCONF Configuration Access Control Model (NACM) [RFC8341]
   provides the means to restrict access for particular NETCONF or
   RESTCONF users to a preconfigured subset of all available NETCONF or
   RESTCONF protocol operations and content.

   There are a number of data nodes defined in this YANG module that are
   writable/creatable/deletable (i.e., config true, which is the
   default).  These data nodes may be considered sensitive in some
   network environments.  Write operations (e.g., edit-config) to these
   data nodes without proper protection can have a negative effect on
   network operations.  These are the subtrees and data nodes and their
   sensitivity/vulnerability:

   o  /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
      node-capabilities/sys:node-selection/sys:node-selector/sec:self-
      describing-attributes/sec:node-tag

   o  /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
      node-capabilities/sys:node-selection/sys:node-selector/sec:self-
      describing-attributes/sec:pm-node-precision

   o  /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
      node-capabilities/sys:node-selection/sys:node-selector/sec:self-
      describing-attributes/sec:pm-node-operation-type

   o  /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
      node-capabilities/sys:node-selection/sys:node-selector/sec:self-
      describing-attributes/sec:node-service-tag



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   o  /sysc:system-capabilities/sysc:datastore-capabilities/sysc:per-
      node-capabilities/sys:node-selection/sys:node-selector/sec:self-
      describing-attributes/sec:node-task-tag

6.  References

6.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC6242]  Wasserman, M., "Using the NETCONF Protocol over Secure
              Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011,
              <https://www.rfc-editor.org/info/rfc6242>.

   [RFC7950]  Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
              RFC 7950, DOI 10.17487/RFC7950, August 2016,
              <https://www.rfc-editor.org/info/rfc7950>.

   [RFC8040]  Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
              Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
              <https://www.rfc-editor.org/info/rfc8040>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8341]  Bierman, A. and M. Bjorklund, "Network Configuration
              Access Control Model", STD 91, RFC 8341,
              DOI 10.17487/RFC8341, March 2018,
              <https://www.rfc-editor.org/info/rfc8341>.

   [RFC8342]  Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K.,
              and R. Wilton, "Network Management Datastore Architecture
              (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018,
              <https://www.rfc-editor.org/info/rfc8342>.



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   [RFC8407]  Bierman, A., "Guidelines for Authors and Reviewers of
              Documents Containing YANG Data Models", BCP 216, RFC 8407,
              DOI 10.17487/RFC8407, October 2018,
              <https://www.rfc-editor.org/info/rfc8407>.

   [RFC8446]  Rescorla, E., "The Transport Layer Security (TLS) Protocol
              Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
              <https://www.rfc-editor.org/info/rfc8446>.

6.2.  Informative References

   [RFC3688]  Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688,
              DOI 10.17487/RFC3688, January 2004,
              <https://www.rfc-editor.org/info/rfc3688>.

   [RFC6020]  Bjorklund, M., Ed., "YANG - A Data Modeling Language for
              the Network Configuration Protocol (NETCONF)", RFC 6020,
              DOI 10.17487/RFC6020, October 2010,
              <https://www.rfc-editor.org/info/rfc6020>.

   [RFC8340]  Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams",
              BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018,
              <https://www.rfc-editor.org/info/rfc8340>.

Authors' Addresses

   Ran Tao
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: taoran20@huawei.com


   Bo Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: lana.wubo@huawei.com









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   Peng Liu
   China Mobile
   32 Xuanwumen West St, Xicheng District
   Beijing  10053

   Email: liupengyjy@chinamobile.com


   Hui Cai
   China Mobile
   32 Xuanwumen West St, Xicheng District
   Beijing  10053

   Email: caihui@chinamobile.com





































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