NETMOD Working Group Q. Wu Internet-Draft Huawei Intended status: Standards Track B. Claise Expires: February 17, 2021 Cisco L. Geng Z. Du China Mobile August 16, 2020 Self Explanation Data Object Tags draft-tao-netmod-yang-node-tags-05 Abstract This document defines a method to tag data objects associated with operation and management data in YANG Modules. This YANG data object tagging method can be used to identify characteristics data and correlate data objects from different data sources and provide input, instruction, indication to selection filter and filter queries of operational state on a server during a "pub/sub" service for YANG datastore updates. When the state of all subscriptions of a particular Subscriber to be fetched is huge, the amount of data to be streamed out to the destination can be greatly reduced and only targeted to the characteristics data. An extension statement to be used to indicate self explanation YANG data object tags that SHOULD be added by the module implementation automatically (i.e., outside of configuration). A YANG module [RFC7950] is defined, which augments Module tag model and provides a list of data object entries to allow for adding or removing of self explanation data object tags as well as viewing the set of self explanation tags associated with the data object within the YANG module. 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 Wu, et al. Expires February 17, 2021 [Page 1] Internet-Draft Self Explanation Tags August 2020 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 February 17, 2021. Copyright Notice Copyright (c) 2020 IETF Trust and the persons identified as the document authors. All rights reserved. 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Self Explanation Data Object Tags Use Cases . . . . . . . 4 1.1.1. Network Performance Data Collection . . . . . . . . . 4 1.1.2. Context Information Tagging . . . . . . . . . . . . . 7 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 8 2. Data Object Tag Values . . . . . . . . . . . . . . . . . . . 8 2.1. IETF Tags Prefix . . . . . . . . . . . . . . . . . . . . 8 2.2. Vendor Tags Prefix . . . . . . . . . . . . . . . . . . . 9 2.3. User Tags Prefix . . . . . . . . . . . . . . . . . . . . 9 2.4. Reserved Tags Prefix . . . . . . . . . . . . . . . . . . 9 3. Data Object Tag Management . . . . . . . . . . . . . . . . . 9 3.1. Module Design Tagging . . . . . . . . . . . . . . . . . . 9 3.2. Implementation Tagging . . . . . . . . . . . . . . . . . 10 3.3. User Tagging . . . . . . . . . . . . . . . . . . . . . . 11 4. Tags Module Structure . . . . . . . . . . . . . . . . . . . . 11 4.1. Tags Module Tree . . . . . . . . . . . . . . . . . . . . 11 5. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 11 6. Guidelines to Model Writers . . . . . . . . . . . . . . . . . 19 6.1. Define Standard Tags . . . . . . . . . . . . . . . . . . 19 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 7.1. YANG Data Object Tag Prefixes Registry . . . . . . . . . 20 7.2. IETF YANG Data Object Tags Registry . . . . . . . . . . . 20 7.3. Updates to the IETF XML Registry . . . . . . . . . . . . 25 7.4. Updates to the YANG Module Names Registry . . . . . . . . 26 8. Security Considerations . . . . . . . . . . . . . . . . . . . 26 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 26 Wu, et al. Expires February 17, 2021 [Page 2] Internet-Draft Self Explanation Tags August 2020 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 27 10.1. Normative References . . . . . . . . . . . . . . . . . . 27 10.2. Informative References . . . . . . . . . . . . . . . . . 27 Appendix A. NETCONF Example . . . . . . . . . . . . . . . . . . 28 Appendix B. Non-NMDA State Module . . . . . . . . . . . . . . . 29 Appendix C. Targeted data object subscription example . . . . . 37 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 40 1. Introduction As described [I.D-ietf-netmod-module-tags], the use of tags for classification and organization is fairly ubiquitous not only within IETF protocols, but in the internet itself (e.g., "#hashtags"). A module tag defined in [I.D-ietf-netmod-module-tags] is a string associated only with a module name at module level. At the time of writing this document (2020), there are many data models that have been specified or are being specified by various different SDOs and Open Souce community. They cover many of the networking protocols and techniques. However data objects defined by these technology specific data models might represent a portion of fault, configuration, accounting, performance, security management categories information (e.g., performance metric specific data object type) at different locations in various different ways, lack consistent classification criteria and representation granularity,e.g., sensor data in hardware model is defined with fine granularity with value scale and value precision while interface model only provides statistics data for specific interface type. This document defines self explanation data object tags and associates them with data objects within YANG module, which o Provide dictionary meaning for specific targeted data objects; o Indicate relationship between data objects within the same YANG module or from different YANG modules; o Identify key performance metric scale, precision, statistics operation type; o Identify specific service or feature, data source. The self explanation data object tags can be used by the client to identify characteristics data and correlate data objects from different data sources and provide input, instruction, indication to selection filter and filter queries of configuration or operational state on a server based on these data object tags,.e.g.,return specific object type of operational state related to system- Wu, et al. Expires February 17, 2021 [Page 3] Internet-Draft Self Explanation Tags August 2020 management. NETCONF clients can discover data objects with self explanation data object tags supported by a NETCONF server via operation. The self explanation data object tag capability can also be advertised via capability notification Model [I- D.netconf-notification-capabilities] by the NETCONF server or some place where offline document are kept. These self explanation tags may be registered as well as assigned during the module definition; assigned by implementations; or dynamically defined and set by users. This document defines a YANG module [RFC7950] which augments module tag model and provides a list of data object entries to allow for adding or removing of self explanation tags as well as viewing the set of self explanation tags associated with a data object within YANG modules. This document defines an extension statement to be used to indicate self explanation tags that SHOULD be added by the module implementation automatically (i.e., outside of configuration). The YANG data model in this document conforms to the Network Management Datastore Architecture defined in [RFC8342]. 1.1. Self Explanation Data Object Tags Use Cases The following is a list of already implemented and potential use cases. 1.1.1. Network Performance Data Collection Among Data object tags, the performance metric tags can be used to capture the performance metrics and properties associated with YANG data nodes or data objects modelled with YANG (See Figure 1). Wu, et al. Expires February 17, 2021 [Page 4] Internet-Draft Self Explanation Tags August 2020 ----- ----- // \\ // \\ | Property+------+ +-------+ Property| \\ A // | | \\ B // -----+ +--V----------------V---+ ----- | YANG Data Node | | /Data Object A | /---\ +--^----------------^---+ /---\ / \ | | / \ |Metric +-------+ +--------|Metric | \ A / \ B / \-+-/ \-+-/ +-------------+ | | |-------------- | Metric Group| /----\ | |-------------+ / \ +-------------+ | |Property| | \ D / | \--+-/ /----\ | +----------------------+ / \ | | YANG Data Node <-------| Metric | +---| /Data Object B | \ C / +----------------------+ \----/ Figure 1 The use of performance metric tags would be to help filter discrete categories of YANG data objects across different YANG modules supported by a device and capture network performance data. If data objects across YANG modules are suitably tagged and learnt by the client from a live server, the client can extract paths to all interested data objects and then use an XPath query to list all related data objects which reflect network characteristics(see Figure 2). Wu, et al. Expires February 17, 2021 [Page 5] Internet-Draft Self Explanation Tags August 2020 +-----------+---------------+-----------+-----------------------+ | Object | Property | Metric | Metric Module | | Name | Name | Group | Name | | | | | | |tunnel-svc | name | - | - tunnel | | | | | | |tunnel-svc | create-time | - | - tunnel | | | | | | |tunnel-svc | modified-time | - | - | | | | | | |tunnel-svc | - |lsp-ping-pm| avg-latency tunnel-pm| | | | | | |tunnel-svc | - |lsp-ping-pm| packet-loss tunnel-pm| | | | | | |tunnel-svc | - |lsp-ping-pm| min-latency tunnel-pm| | | | | | |tunnel-svc | - |lsp-ping-pm| max-latency tunnel-pm| | | | |transmitted | |tunnel-svc | - |lsp-ping-pm| -packet tunnel-pm| +-----------+---------------+-----------+-----------------------+ +---------------------------------------------------------+ | Metric Metric Metric Metric Operation | | Group Name Precision Scale Type | | | | lsp-ping-pm avg- 1 1 avg | | latency | | | | lsp-ping-pm packet- 1 1 avg | | loss | | | | | | lsp-ping-pm min- 1 1 min | | latency | | | | | | lsp-ping-pm max- 1 1 max | | latency | | | | | | lsp-ping-pm transmitted 1 1 normal | | -packet | +---------------------------------------------------------+ Figure 2 Wu, et al. Expires February 17, 2021 [Page 6] Internet-Draft Self Explanation Tags August 2020 1.1.2. Context Information Tagging Performance metric tags can also be used to help correlate data objects with the same characteristics when clients are interacting with various different devices with the different categories of YANG data node across different YANG modules. For example, one management client could mark some specific data node across modules implemented in various different devices with the same metric group tag as context information, so consistent representation and reporting can be provided for YANG data nodes belonging to the same metric group (see Figure 2). Another example is the management client could mark some data node across different level of YANG modules implemented in the device, the management system separately with the same service tag (e.g., L3VPN Service) as context information, so root cause can be identified efficiently during network failure troubleshooting (See Figure 3) +--------------+ | Parent object| +-------^------+ | ----- +-----+-----+ ----- // \\ |Service Tag| // \\ | Property+------+ ++--------+-+ +-------+ Property| \\ A // | | | | \\ B // -----+ +--V---V-+ +-V---V--+ ----- | Child | | Child | |ObjectA | |ObjectB | /---\ +--^-----+ +-----^--+ /---\ / \ | | / \ |Metric +-------+ +--------|Metric | \ A / \ B / \---/ \---/ Figure 3 Wu, et al. Expires February 17, 2021 [Page 7] Internet-Draft Self Explanation Tags August 2020 +-----------------------------------------------------------+ | Service Metric Metric Module Level | | Tag Group Name | | | | L3VPN L3VPN maximum L3VPN Service | | -routes | | | | L3VPN OSPF-Process total-active OSPF Device | | routes | | | | total-active | | L3VPN RIP-Process routes RIP Device | | | | total-active | | L3VPN BGP-Process routes BGP Device | | | +-----------------------------------------------------------+ Figure 4 1.2. 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. Data Object Tag Values All data object tags SHOULD begin with a prefix indicating who owns their definition. An IANA registry (Section 7.1) is used to support registering data object tag prefixes. Currently 3 prefixes are defined. No further structure is imposed by this document on the value following the registered prefix, and the value can contain any YANG type 'string' characters except carriage-returns, newlines and tabs. Therefore, designers, implementers, and users are free to add or not add any structure they may require to their own tag values. 2.1. IETF Tags Prefix An IETF tag is a data object tag that has the prefix "ietf:". All IETF data object tags are registered with IANA in a registry defined later in this document (Section 7.2). Wu, et al. Expires February 17, 2021 [Page 8] Internet-Draft Self Explanation Tags August 2020 2.2. Vendor Tags Prefix A vendor tag is a tag that has the prefix "vendor:". These tags are defined by the vendor that implements the module, and are not registered; however, it is RECOMMENDED that the vendor include extra identification in the tag to avoid collisions such as using the enterprise or organization name following the "vendor:" prefix (e.g., vendor:vendor-defined-classifier). 2.3. User Tags Prefix A user tag is any tag that has the prefix "user:". These tags are defined by the user/administrator and are not meant to be registered. Users are not required to use the "user:" prefix; however, doing so is RECOMMENDED as it helps avoid prefix collisions. 2.4. Reserved Tags Prefix Any tag not starting with the prefix "ietf:", "vendor:" or "user:" is reserved for future use. These tag values are not invalid, but simply reserved in the context of specifications (e.g., RFCs). 3. Data Object Tag Management Tags can become associated with a data object within YANG module in a number of ways. Tags may be defined and associated at the module design time, at implementation time without the need of live server, or via user administrative control . As the main consumer of data object tags are users, users may also remove any tag from a live server, no matter how the tag became associated with a data object within a YANG module. 3.1. Module Design Tagging A data node definition MAY indicate a set of data object tags to be added by the module implementer. These design time tags are indicated using a set of extension statements which include: opm-tag extension statement: Classify management and operation data into object type, property and metric three categories. metric-scale extension statement: Provide an additional metric scale (e.g., Measurement scaling factor of 10^0, 10^-3,10^3) information associated with the performance metric data object within YANG module. ; metric-precision extension statement: Provide an additional metric precision (e.g., the range -8 to -1, 0, the range 1 to 9) Wu, et al. Expires February 17, 2021 [Page 9] Internet-Draft Self Explanation Tags August 2020 information associated with the performance metric data object within YANG module. ; operation-type extension statement: Statistics operation of performance metric data object within YANG module, The statistics operation include normal,min, max, average, sum,threshold. metric-group extension statement: Provide correlation between different metric information associated with data object within YANG module. data-source extension statement: The data source type (e.g., connectivity,resource, hardware ,qos,policy) associated with the performance metric data object within YANG module. multi-source-tag extension statement: Identify multiple source aggregation tye(e.g., line card,member link in an aggregated Ethernet interface) related to performance metric data object or interface related data object). Two source aggregation source types are supported, one is aggregation, the other is membership. service-tag extension statement: Provide a service classification information (e.g., tunnel, l3vpn,l2vpn) information associated with data object within YANG module; task-tag extension statement: Provide a task classification information (e.g., fault management, performance measurement) information associated with data object within YANG module. Among these extension statements, the opm-tag extension statement,meric-scale extension statement, metric-precision extension statement,operation-type extension statement are performance meric related while metric-group extension statement,data-source extension statement, multi-source-tag extension statement, service-tag extension statement, task-tag extension statement are context information related. If the data node is defined in an IETF standards track document, the data object tags MUST be IETF Tags (2.1). Thus, new data object can drive the addition of new IETF tags to the IANA registry defined in Section 7.2, and the IANA registry can serve as a check against duplication. 3.2. Implementation Tagging An implementation MAY include additional tags associated with data object within a YANG module. These tags SHOULD be IETF Tags (i.e., registered) or vendor specific tags. Wu, et al. Expires February 17, 2021 [Page 10] Internet-Draft Self Explanation Tags August 2020 3.3. User Tagging Data object tags of any kind, with or without a prefix, can be assigned and removed by the user from a live server using normal configuration mechanisms. In order to remove a data object tag from the operational datastore, the user adds a matching "masked-tag" entry for a given data object within the ietf-data-object-tags Module. 4. Tags Module Structure 4.1. Tags Module Tree The tree associated with the "ietf-data-object-tags" module follows. The meaning of the symbols can be found in [RFC8340]. module: ietf-data-object-tags augment /tags:module-tags/tags:module: +--rw data-object-tags +--rw data-object* [object-name] +--rw object-name nacm:node-instance-identifier +--rw tag* tags:tag +--rw masked-tag* tags:tag 5. YANG Module file "ietf-data-object-tags@2019-05-03.yang" module ietf-data-object-tags { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-data-object-tags"; prefix ntags; import ietf-netconf-acm { prefix nacm; } import ietf-module-tags { prefix tags; } organization "IETF NetMod Working Group (NetMod)"; contact "WG Web: WG List: Editor: Qin Wu Editor: Benoit Claise Editor: Liang Geng Editor: Zongpeng Du "; Wu, et al. Expires February 17, 2021 [Page 11] Internet-Draft Self Explanation Tags August 2020 description "This module describes a mechanism associating self-explanation tags with YANG data object within YANG modules. Tags may be IANA assigned or privately defined. 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 (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://tools.ietf.org/html/rfcXXXX); see the RFC itself for full legal notices."; revision 2019-05-03 { description "Initial revision."; reference "RFC XXXX: YANG Data Object Tags"; } typedef metric-precision { type int8 { range "-8 .. 9"; } description "A node using this data type represents a sensor value precision range. A node of this type SHOULD be defined together with nodes of type measurement-units and type measurement-scale. Together, associated nodes of these three types are used to identify the semantics of a node of type sensor-value. If a node of this type contains a value in the range 1 to 9, it represents the number of decimal places in the fractional part of an associated sensor-value fixed-point number. If a node of this type contains a value in the range -8 to -1, it represents the number of accurate digits in the associated sensor-value fixed-point number. The value zero indicates the associated sensor-value node is not a fixed-point number. Wu, et al. Expires February 17, 2021 [Page 12] Internet-Draft Self Explanation Tags August 2020 Server implementers must choose a value for the associated sensor-value-precision node so that the precision and accuracy of the associated sensor-value node is correctly indicated. For example, a component representing a temperature sensor that can measure 0 to 100 degrees C in 0.1 degree increments, +/- 0.05 degrees, would have a sensor-value-precision value of '1', a sensor-value-scale value of 'units', and a sensor-value ranging from '0' to '1000'. The sensor-value would be interpreted as 'degrees C * 10'."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorPrecision"; } typedef metric-scale { type enumeration { enum yocto { value 1; description "Measurement scaling factor of 10^-24."; } enum zepto { value 2; description "Measurement scaling factor of 10^-21."; } enum atto { value 3; description "Measurement scaling factor of 10^-18."; } enum femto { value 4; description "Measurement scaling factor of 10^-15."; } enum pico { value 5; description "Measurement scaling factor of 10^-12."; } enum nano { value 6; description "Measurement scaling factor of 10^-9."; } Wu, et al. Expires February 17, 2021 [Page 13] Internet-Draft Self Explanation Tags August 2020 enum micro { value 7; description "Measurement scaling factor of 10^-6."; } enum milli { value 8; description "Measurement scaling factor of 10^-3."; } enum units { value 9; description "Measurement scaling factor of 10^0."; } enum kilo { value 10; description "Measurement scaling factor of 10^3."; } enum mega { value 11; description "Measurement scaling factor of 10^6."; } enum giga { value 12; description "Measurement scaling factor of 10^9."; } enum tera { value 13; description "Measurement scaling factor of 10^12."; } enum peta { value 14; description "Measurement scaling factor of 10^15."; } enum exa { value 15; description "Measurement scaling factor of 10^18."; } enum zetta { value 16; description Wu, et al. Expires February 17, 2021 [Page 14] Internet-Draft Self Explanation Tags August 2020 "Measurement scaling factor of 10^21."; } enum yotta { value 17; description "Measurement scaling factor of 10^24."; } } description "A node using this data type represents a data scaling factor, represented with an International System of Units (SI) prefix. The actual data units are determined by examining a node of this type together with the associated sensor-value-type. A node of this type SHOULD be defined together with nodes of type sensor-value-type and type sensor-value-precision. Together, associated nodes of these three types are used to identify the semantics of a node of type sensor-value."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorDataScale"; } extension opm-tag { argument tag; description "The argument 'tag' is of type 'tag'. This extension statement is used by module authors to indicate the opm tags that SHOULD be added automatically by the system. Opm Tag is used to classify operation and management data into object type, property, and metric As such the origin of the value for the pre-defined tags should be set to 'system'[RFC8342]."; } extension metric-scale { argument tag; description "The argument 'tag' is of type 'tag'. The metric-scale tag can be used to provide an additional data scale factor(e.g., Measurement scaling factor of 10^0, 10^-3,10^3) information associated with the performance metric data object. A node using metric scale tag SHOULD be defined together with nodes of type metric unit and type metric precision. Together, associated nodes of these three types are used to identify the semantics of the performance metric data object."; reference "RFC 3433: Entity Sensor Management Information Base - Wu, et al. Expires February 17, 2021 [Page 15] Internet-Draft Self Explanation Tags August 2020 EntitySensorDataScale"; } extension metric-precision { argument tag; description "The argument 'tag' is of type 'tag'. The metric-precision can be used to provide an additional sensor value precision range (e.g., the range -8 to -1, 0, the range 1 to 9) information associated with the performance metric data object. A node using metric precision tag SHOULD be defined together with nodes of type metric unit and type metric scale. Together, associated nodes of these three types are used to identify the semantics of the performance metric data object. If a node of this type contains a value in the range 1 to 9, it represents the number of decimal places in the fractional part of an associated sensor-value fixed-point number. If a node of this type contains a value in the range -8 to -1, it represents the number of accurate digits in the associated sensor-value fixed-point number. The value zero indicates the associated sensor-value node is not a fixed-point number. Server implementers must choose a value for the associated metric precision tag so that the precision and accuracy of the associated sensor-value node is correctly indicated. For example, a component representing a temperature sensor that can measure 0 to 100 degrees C in 0.1 degree increments, +/- 0.05 degrees, would have a sensor-value-precision value of '1', a sensor-value-scale value of 'units', and a sensor-value ranging from '0' to '1000'. The sensor-value would be interpreted as 'degrees C * 10'."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorDataScale"; } extension operation-type { argument tag; description "The argument 'tag' is of type 'tag'.The statistics-operation can be used to provide an additional statistics operation type(e.g., sum, min, max,sum,last, threshold) information associated with the performance metric Wu, et al. Expires February 17, 2021 [Page 16] Internet-Draft Self Explanation Tags August 2020 data object. If the operation type is threshold type, the corresponding data object support threshold handling,e.g.,scan all interfaces for a certain type every 5 seconds and check the counters or status to cross threshold, return an array of interface entries that match the search. If the operation type is average,min,max,sum,last, it indicate the data object supports statistics operation, e.g., scan all interfaces for a certain type every 5 seconds up to 60 seconds, only return min, average, max, sum value of specific data object rather than the values that are current at the end of 60 seconds."; } extension metric-group { argument tag; description "The argument 'tag' is of type 'tag'.The metric-group can be used to provide correlation between different metric information associated with YANG data object."; } extension service-tag { argument tag; description "The argument 'tag' is of type 'tag'.The service-tag can be used to provide a service classification information (e.g., tunnel, l3vpn,l2vpn) information associated with YANG data object."; } extension task-tag { argument tag; description "The argument 'tag' is of type 'tag'.The task-tag can be used to provide a task classification information (e.g., fault management, performance measurement) information associated with YANG data object."; } extension data-source { argument tag; description "The argument 'tag' is of type 'tag'.The data-source-type can be used to provide an additional data source type (e.g., connectivity, resource, hardware,qos,policy) information associated with the performance metric data object."; } Wu, et al. Expires February 17, 2021 [Page 17] Internet-Draft Self Explanation Tags August 2020 extension multi-source-tag { argument tag; description "The argument 'tag' is of type 'tag'.The multi-source-tag can be used to identify multiple source aggregation tye(e.g., line card, member link in an aggregated Ethernet interface) related to performance metric data object or interface related to data object). Two source aggregation source types are supported, one is aggregation which groups data from two or multiple different data objects, the other is membership which identify each data object(e.g., linecard, member link from multiple source aggregation."; } augment "/tags:module-tags/tags:module" { description "Augment the Module Tags module with data object tag attributes"; container data-object-tags { description "Contains the list of data objects and their associated self explanation tags"; list data-object { key "object-name"; description "A list of self explanation nodes and their associated tags"; leaf object-name { type nacm:node-instance-identifier; mandatory true; description "The YANG data object name."; } leaf-list tag { type tags:tag; description "Tags associated with the data object within YANG module. See the IANA 'YANG Data Object Tag Prefixes' registry for reserved prefixes and the IANA'IETF YANG Data Object Tags' registry for IETF tags. The 'operational' state [RFC8342] view of this list is constructed using the following steps: 1) System tags (i.e., tags of 'system' origin) are added. 2) User configured tags (i.e., tags of 'intended' origin) are added. 3) Any tag that is equal to a masked-tag is removed."; } leaf-list masked-tag { type tags:tag; Wu, et al. Expires February 17, 2021 [Page 18] Internet-Draft Self Explanation Tags August 2020 description "The list of tags that should not be associated with the data object within YANG module. The user can remove (mask) tags from the operational state datastore [RFC8342] by adding them to this list. It is not an error to add tags to this list that are not associated with the data object within YANG module, but they have no operational effect."; } } } } } 6. Guidelines to Model Writers This section updates [RFC8407]. 6.1. Define Standard Tags A module MAY indicate, using node-tag extension statements, a set of tags that are to be automatically associated with it (i.e., not added through configuration). module example-module-A { //... import ietf-data-node-tags { prefix ntags; } container top { ntags:opm-tag "ietf:object-type"; list X { leaf foo { ntags:opm-tag "ietf:property"; } } container Y { ntags:opm-tag "ietf:metric"; leaf bar { ntags:operation-type "ietf:avg"; ntags:metric-scale "ietf:milli"; } } } // ... } The module writer can use existing standard tags, or use new tags defined in the model definition, as appropriate. For IETF Wu, et al. Expires February 17, 2021 [Page 19] Internet-Draft Self Explanation Tags August 2020 standardized modules new data object tags MUST be assigned in the IANA registry defined below, see Section Section 7.2. 7. IANA Considerations 7.1. YANG Data Object Tag Prefixes Registry IANA is asked to create a new registry "YANG Data Object Tag Prefixes" grouped under a new "Protocol" category named "YANG Data Object Tag Prefixes". This registry allocates tag prefixes. All YANG Data Object Tags SHOULD begin with one of the prefixes in this registry. Prefix entries in this registry should be short strings consisting of lowercase ASCII alpha-numeric characters and a final ":" character. The allocation policy for this registry is Specification Required [RFC8126]. The Reference and Assignee values should be sufficient to identify and contact the organization that has been allocated the prefix. The initial values for this registry are as follows. +----------+----------------------------------+-----------+----------+ | Prefix | Description | Reference | Assignee | +----------+----------------------------------+-----------+----------+ | ietf: | IETF Tags allocated in the IANA | [This | IETF | | | IETF YANG Data Object Tags registry document]| | | | | | | |vendor: | Non-registered tags allocated by | [This | IETF | | | the module implementer. | document] | | | | | | | | user: | Non-registered tags allocated by | [This | IETF | | | and for the user. | document] | | +----------+----------------------------------+-----------+----------+ Other standards organizations (SDOs) wishing to allocate their own set of tags should allocate a prefix from this registry. 7.2. IETF YANG Data Object Tags Registry IANA is asked to create nine new registries "IETF Data Object Tags","IETF Metric Precision Tags","IETF Metric Scale Tags","IETF Operation Type Tags","IETF Metric Group Tags","IETF Data Source Tags","IETF Multiple Source Tags","IETF Service Tags","IETF Task Tags" grouped under a new "Protocol" category. These nine registries Wu, et al. Expires February 17, 2021 [Page 20] Internet-Draft Self Explanation Tags August 2020 should be included below "YANG Data Object Tag Prefixes" when listed on the same page. Nine registries allocate tags that have the registered prefix "ietf:". New values should be well considered and not achievable through a combination of already existing IETF tags. The allocation policy for these four registries is IETF Review [RFC8126]. The initial values for these nine registries are as follows. +----------------------------+--------------------------+-----------+ | OPM Tag | Description | Reference | +----------------------------+--------------------------+-----------+ | | | | | ietf:object-type | Relates to object type | [This | | | (e.g., interfaces). | document] | | | | | | ietf:metric | Relates to performance | [This | | | metric info | document] | | | (e.g., ifstatistics). | | | | | | | | | | | ietf:property | Represents a object | [This | | | property | document] | | | (e.g.,ifindex). | | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Metric Precision Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:minus-eight |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-seven |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-six |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-five |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-four |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-three |Relates to metric precision [This | | | of performance metric | document] | Wu, et al. Expires February 17, 2021 [Page 21] Internet-Draft Self Explanation Tags August 2020 | | | | |ietf:minus-two |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:minus-one |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:zero |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:one |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:two |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:three |Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:four | Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:five | Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:six | Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:seven | Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:eight | Relates to metric precision [This | | | of performance metric | document] | | | | | |ietf:nine | Relates to metric precision [This | | | of performance metric | document] | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Metric Scale Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:yocto | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf:zepto | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf:atto | Relates to metric scale | [This | | | of performance metric | document] | Wu, et al. Expires February 17, 2021 [Page 22] Internet-Draft Self Explanation Tags August 2020 | | | | |ietf: femto | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: pico | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: nano | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: micro | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: milli | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: units | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: kilo | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: mega | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: giga | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: tera | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: peta | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: exa | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: zetta | Relates to metric scale | [This | | | of performance metric | document] | | | | | |ietf: yotta | Relates to metric scale | [This | | | of performance metric | document] | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Operation Type Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:normal | Relates to statistics | [This | | | operation(e.g.,average, | document] | Wu, et al. Expires February 17, 2021 [Page 23] Internet-Draft Self Explanation Tags August 2020 | | min, max, normal,etc) | | |ietf:avg | Relates to statistics | [This | | | operation(e.g.,average, | document] | | | min, max, sum,etc) | | |ietf:sum | Relates to statistics | [This | | | operation(e.g.,average, | document] | | | min, max, sum,etc) | | |ietf:min | Relates to statistics | [This | | | operation(e.g.,average, | document] | | | min, max, sum,etc) | | |ietf:max | Relates to statistics | [This | | | operation(e.g.,average, | document] | | | min, max, sum,etc) | | |ietf:threshold | Relates to statistics | [This | | | operation(e.g.,average, | document] | | | min, max, threshold,etc) | | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Metric Group Tag | Description | Reference | +----------------------------+--------------------------+-----------+ | ietf:delay | Represent metric group | [This | | |(e.g., loss, jitter,delay)| document] | | | | | | ietf:jitter | Represent metric group | [This | | |(e.g., loss, jitter,delay)| document] | | | | | | ietf:loss | Represent metric group | [This | | |(e.g., loss, jitter,delay)| document] | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Multiple Source Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:member |Relates to multiple source| [This | | |aggregation type(e.g., | document] | | |lag, linecard, sub inf) | | | | | | |ietf:agg |Relates to multiple source| [This | | |aggregation type(e.g.,agg)| document] | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Data Source Tag | Description | Reference | +----------------------------+--------------------------+-----------+ | | | | | ietf:service-flow | Relates to data source | [This | | | type(e.g., microburst). | document] | | | | | | ietf:topo | Relates to data source | [This | | | type(e.g., topology). | document] | Wu, et al. Expires February 17, 2021 [Page 24] Internet-Draft Self Explanation Tags August 2020 | | | | | ietf:resource | Relates to data source | [This | | | type info | document] | | | (e.g., interface,queue). | | | | | | | ietf:policy | Relates to data source | [This | | | type info | document] | | |(e.g., acl, routing policy| | | | | | | ietf:hardware | Relates to data source | [This | | | type | document] | | | (e.g.,optical module). | | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Service Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:l3vpn | Relates to service | [This | | | offering(e.g.,l3vpn | document] | | | l2vpn,tunnel,etc) | | |ietf:l2vpn | Relates to service | [This | | | offering(e.g.,l3vpn | document] | | | l2vpn,tunnel,etc) | | |ietf:te-tunnel | Relates to service | [This | | | offering(e.g.,l3vpn | document] | | | l2vpn,tunnel,etc) | | +----------------------------+--------------------------+-----------+ +----------------------------+--------------------------+-----------+ | Task Tag | Description | Reference | +----------------------------+--------------------------+-----------+ |ietf:vpn-diag | Relates to vpn serivce | [This | | | diagonostic function | document] | | | | | |ietf:vpn-fullfilment | Relates to vpn service | [This | | | fullfillment function | document] | | | | | |ietf:vpn-assurance | Relates to vpn service | [This | | | assurance function | document] | +----------------------------+--------------------------+-----------+ 7.3. 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: Wu, et al. Expires February 17, 2021 [Page 25] Internet-Draft Self Explanation Tags August 2020 URI: urn:ietf:params:xml:ns:yang:ietf-data-object-tags Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. 7.4. 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: name: ietf-data-object-tags namespace: urn:ietf:params:xml:ns:yang:ietf-data-object-tags prefix: ntags reference: RFC XXXX (RFC Ed.: replace XXX with actual RFC number and remove this note.) 8. Security Considerations The YANG module defined in this memo is designed to be accessed via the NETCONF protocol [RFC6241]. The lowest NETCONF layer is the secure transport layer and the mandatory-to-implement secure transport is SSH [RFC6242]. This document adds the ability to associate data object tag meta-data with data object within the YANG modules. This document does not define any actions based on these associations, and none are yet defined, and therefore it does not by itself introduce any new security considerations. Users of the data object tag-meta data may define various actions to be taken based on the data object tag meta-data. These actions and their definitions are outside the scope of this document. Users will need to consider the security implications of any actions they choose to define. 9. Contributors The authors would like to thank Ran Tao for his major contributions to the initial modeling and use cases. Wu, et al. Expires February 17, 2021 [Page 26] Internet-Draft Self Explanation Tags August 2020 10. References 10.1. 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, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [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, . [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . 10.2. Informative References [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . Wu, et al. Expires February 17, 2021 [Page 27] Internet-Draft Self Explanation Tags August 2020 [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Appendix A. NETCONF Example The following is a fictional NETCONF example result from a query of the data object tags list. For the sake of brevity only a few module results are imagined. Wu, et al. Expires February 17, 2021 [Page 28] Internet-Draft Self Explanation Tags August 2020 ietf-interfaces /if:interfaces/if:interface/if:statistics/if:in-errors ietf:metric ietf:avg /if:interfaces/if:interface/if:last-change ietf:property /if:interfaces/if:interface/if:type ietf:object-type ietf-ip /if:interfaces/if:interface/ip:ipv4/ip:mtu ietf:metric ietf:normal /if:interfaces/if:interface/ip:ipv4/ip:enable ietf:property /if:interfaces/if:interface/ip:ipv4 ietf:object-type Appendix B. Non-NMDA State Module As per [RFC8407] the following is a non-NMDA module to support viewing the operational state for non-NMDA compliant servers. Wu, et al. Expires February 17, 2021 [Page 29] Internet-Draft Self Explanation Tags August 2020 file "ietf-data-object-tags-state@2019-05-03.yang" module ietf-data-object-tags-state { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-data-object-tags"; prefix ntags; import ietf-netconf-acm { prefix nacm; } import ietf-module-tags { prefix tags; } organization "IETF NetMod Working Group (NetMod)"; contact "WG Web: WG List: Editor: Qin Wu Editor: Benoit Claise Editor: Liang Geng Editor: Zongpeng Du "; description "This module describes a mechanism associating self-explanation tags with YANG data object within YANG modules. Tags may be IANA assigned or privately defined. 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 (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://tools.ietf.org/html/rfcXXXX); see the RFC itself for full legal notices."; revision 2019-05-03 { description "Initial revision."; reference "RFC XXXX: YANG Data Object Tags"; } Wu, et al. Expires February 17, 2021 [Page 30] Internet-Draft Self Explanation Tags August 2020 typedef metric-precision { type int8 { range "-8 .. 9"; } description "A node using this data type represents a sensor value precision range. A node of this type SHOULD be defined together with nodes of type measurement-units and type measurement-scale. Together, associated nodes of these three types are used to identify the semantics of a node of type sensor-value. If a node of this type contains a value in the range 1 to 9, it represents the number of decimal places in the fractional part of an associated sensor-value fixed-point number. If a node of this type contains a value in the range -8 to -1, it represents the number of accurate digits in the associated sensor-value fixed-point number. The value zero indicates the associated sensor-value node is not a fixed-point number. Server implementers must choose a value for the associated sensor-value-precision node so that the precision and accuracy of the associated sensor-value node is correctly indicated. For example, a component representing a temperature sensor that can measure 0 to 100 degrees C in 0.1 degree increments, +/- 0.05 degrees, would have a sensor-value-precision value of '1', a sensor-value-scale value of 'units', and a sensor-value ranging from '0' to '1000'. The sensor-value would be interpreted as 'degrees C * 10'."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorPrecision"; } typedef metric-scale { type enumeration { enum yocto { value 1; description "Measurement scaling factor of 10^-24."; } enum zepto { value 2; Wu, et al. Expires February 17, 2021 [Page 31] Internet-Draft Self Explanation Tags August 2020 description "Measurement scaling factor of 10^-21."; } enum atto { value 3; description "Measurement scaling factor of 10^-18."; } enum femto { value 4; description "Measurement scaling factor of 10^-15."; } enum pico { value 5; description "Measurement scaling factor of 10^-12."; } enum nano { value 6; description "Measurement scaling factor of 10^-9."; } enum micro { value 7; description "Measurement scaling factor of 10^-6."; } enum milli { value 8; description "Measurement scaling factor of 10^-3."; } enum units { value 9; description "Measurement scaling factor of 10^0."; } enum kilo { value 10; description "Measurement scaling factor of 10^3."; } enum mega { value 11; description "Measurement scaling factor of 10^6."; } Wu, et al. Expires February 17, 2021 [Page 32] Internet-Draft Self Explanation Tags August 2020 enum giga { value 12; description "Measurement scaling factor of 10^9."; } enum tera { value 13; description "Measurement scaling factor of 10^12."; } enum peta { value 14; description "Measurement scaling factor of 10^15."; } enum exa { value 15; description "Measurement scaling factor of 10^18."; } enum zetta { value 16; description "Measurement scaling factor of 10^21."; } enum yotta { value 17; description "Measurement scaling factor of 10^24."; } } description "A node using this data type represents a data scaling factor, represented with an International System of Units (SI) prefix. The actual data units are determined by examining a node of this type together with the associated sensor-value-type. A node of this type SHOULD be defined together with nodes of type sensor-value-type and type sensor-value-precision. Together, associated nodes of these three types are used to identify the semantics of a node of type sensor-value."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorDataScale"; } extension opm-tag { argument tag; Wu, et al. Expires February 17, 2021 [Page 33] Internet-Draft Self Explanation Tags August 2020 description "The argument 'tag' is of type 'tag'. This extension statement is used by module authors to indicate the opm tags that SHOULD be added automatically by the system. Opm Tag is used to classify operation and management data into object type, property, and metric. As such the origin of the value for the pre-defined tags should be set to 'system'[RFC8342]."; } extension metric-scale { argument tag; description "The argument 'tag' is of type 'tag'. The metric-scale tag can be used to provide an additional data scale factor(e.g., Measurement scaling factor of 10^0, 10^-3,10^3) information associated with the performance metric data object. A node using metric scale tag SHOULD be defined together with nodes of type metric unit and type metric precision. Together, associated nodes of these three types are used to identify the semantics of the performance metric data object."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorDataScale"; } extension metric-precision { argument tag; description "The argument 'tag' is of type 'tag'. The metric-precision can be used to provide an additional sensor value precision range (e.g., the range -8 to -1, 0, the range 1 to 9) information associated with the performance metric data object. A node using metric precision tag SHOULD be defined together with nodes of type metric unit and type metric scale. Together, associated nodes of these three types are used to identify the semantics of the performance metric data object. If a node of this type contains a value in the range 1 to 9, it represents the number of decimal places in the fractional part of an associated sensor-value fixed-point number. If a node of this type contains a value in the range -8 to -1, it represents the number of accurate digits in the associated sensor-value fixed-point number. The value zero indicates the associated sensor-value node is not a fixed-point number. Wu, et al. Expires February 17, 2021 [Page 34] Internet-Draft Self Explanation Tags August 2020 Server implementers must choose a value for the associated metric precision tag so that the precision and accuracy of the associated sensor-value node is correctly indicated. For example, a component representing a temperature sensor that can measure 0 to 100 degrees C in 0.1 degree increments, +/- 0.05 degrees, would have a sensor-value-precision value of '1', a sensor-value-scale value of 'units', and a sensor-value ranging from '0' to '1000'. The sensor-value would be interpreted as 'degrees C * 10'."; reference "RFC 3433: Entity Sensor Management Information Base - EntitySensorDataScale"; } extension operation-type { argument tag; description "The argument 'tag' is of type 'tag'.The statistics-operation can be used to provide an additional statistics operation type(e.g., sum, min, max,sum,last, threshold) information associated with the performance metric data object. If the operation type is threshold type, the corresponding data object support threshold handling,e.g.,scan all interfaces for a certain type every 5 seconds and check the counters or status to cross threshold, return an array of interface entries that match the search. If the operation type is average,min,max,sum,last, it indicate the data object supports statistics operation, e.g., scan all interfaces for a certain type every 5 seconds up to 60 seconds, only return min, average, max, sum value of specific data object rather than the values that are current at the end of 60 seconds."; } extension service-tag { argument tag; description "The argument 'tag' is of type 'tag'.The service-tag can be used to provide a service classification information (e.g., tunnel, l3vpn,l2vpn) information associated with YANG data object."; } extension task-tag { argument tag; description Wu, et al. Expires February 17, 2021 [Page 35] Internet-Draft Self Explanation Tags August 2020 "The argument 'tag' is of type 'tag'.The task-tag can be used to provide a task classification information (e.g., fault management, performance measurement) information associated with YANG data object."; } extension data-source { argument tag; description "The argument 'tag' is of type 'tag'.The data-source-type can be used to provide an additional data source type (e.g., connectivity, resource, hardware,qos,policy) information associated with the performance metric data object tag."; } extension multi-source-tag { argument tag; description "The argument 'tag' is of type 'tag'.The multi-source-tag can be used to identify multiple source aggregation tye(e.g., line card, member link in an aggregated Ethernet interface) related to performance metric data objects or interface related data objects). Two source aggregation source types are supported, one is aggregation which groups data from two or multiple different data objects, the other is membership which identify each data object(e.g., linecard, member link from multiple source aggregation."; } augment "/tags:module-tags/tags:module" { description "Augment the Module Tags module with data object tag attributes"; container data-object-tags { config false; status deprecated; description "Contains the list of data objects and their associated self explanation tags"; list data-object { key "object-name"; status deprecated; description "A list of self explanation nodes and their associated tags"; leaf object-name { type nacm:node-instance-identifier; mandatory true; status deprecated; description "The YANG data object name."; } Wu, et al. Expires February 17, 2021 [Page 36] Internet-Draft Self Explanation Tags August 2020 leaf-list tag { type tags:tag; status deprecated; description "Tags associated with the data object within YANG module. See the IANA 'YANG Data Object Tag Prefixes' registry for reserved prefixes and the IANA'IETF YANG Data Object Tags' registry for IETF tags. The 'operational' state [RFC8342] view of this list is constructed using the following steps: 1) System tags (i.e., tags of 'system' origin) are added. 2) User configured tags (i.e., tags of 'intended' origin) are added. 3) Any tag that is equal to a masked-tag is removed."; } leaf-list masked-tag { type tags:tag; status deprecated; description "The list of tags that should not be associated with the data object within YANG module. The user can remove (mask) tags from the operational state datastore [RFC8342] by adding them to this list. It is not an error to add tags to this list that are not associated with the data object within YANG module, but they have no operational effect."; } } } } } Appendix C. Targeted data object subscription example The following subsections provides targeted data object subscription example.The subscription "id" values of 22 used below is just an example. In production, the actual values of "id" might not be small integers. Wu, et al. Expires February 17, 2021 [Page 37] Internet-Draft Self Explanation Tags August 2020 +-----------+ +-----------+ | Subscriber| | Publisher | +------+----+ +-----+-----+ | | | | |Telemery data Tagging Advertisement | (node-selector, opm-tag = metric) |<---------------------------------| | | | establish-subscription | | (datasore,node-selector) | |--------------------------------->| | | | | | | | RPC Reply: OK, id = 22 | |<---------------------------------| | | | | | | | Notification Message (for 22) | | <--------------------------------| | | | | | | The publisher advertise telemetry data object capability to the subscriber to instruct the receiver to subscribe targeted data object with specific characteristics (e.g., performance metric data object) and specific data path corresponding to the targeted data object. The following XML example [W3C.REC-xml-20081126] illustrates the advertisment of the list of available target objects: Wu, et al. Expires February 17, 2021 [Page 38] Internet-Draft Self Explanation Tags August 2020 acme-router-notification-capabilities ietf-system-capabilities@2020-03-23 ietf-notification-capabilities@2020-03-23 ietf-data-export-capabilities@2020-03-23 Defines the notification capabilities of an acme-router. The router only has running, and operational datastores. Every change can be reported on-change from running, but only config=true nodes and some config=false data from operational. Statistics are not reported based on timer based trigger and counter threshold based trigger. ds:operational \ /if:interfaces/if:interface/if:statistics/if:in-errors\ counter metric avg With telemetry data tagging information carried in the Telemetry data Tagging Advertisement, the subscriber identifies targeted data object and associated data path to the datastore node and sends a establish- subscription RPC to subscribe specific data objects that are interests to the client application from the publisher. Wu, et al. Expires February 17, 2021 [Page 39] Internet-Draft Self Explanation Tags August 2020 ds:operational /if:interfaces/if:interface/if:statistics/if:in-errors 500 The publisher returns specific object type of operational state subscribed by the client. Authors' Addresses Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China Email: bill.wu@huawei.com Benoit Claise Cisco De Kleetlaan 6a b1 Diegem 1831 Belgium Email: bclaise@cisco.com Liang Geng China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: gengliang@chinamobile.com Wu, et al. Expires February 17, 2021 [Page 40] Internet-Draft Self Explanation Tags August 2020 Zongpeng Du China Mobile 32 Xuanwumen West St, Xicheng District Beijing 10053 Email: duzongpeng@chinamobile.com Wu, et al. Expires February 17, 2021 [Page 41]